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My Chemical-Free House

A Guide to Creating a Healthy Home

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Healthy Building

Guide to Non-Toxic Flooring 2021

September 11, 2019 by Corinne 207 Comments

Updated Winter 2020/2021

The best options are real hardwood, polished concrete, and tile. But specific brands of natural linoleum, carpet, and engineered wood are excellent choices as well.

There are many choices for non-toxic flooring suitable for the chemically sensitive or the health-conscious homeowner.

I will look at a few options that are still non-toxic, but not quite as healthy, like luxury vinyl plank, laminate, cork, and bamboo.

If you need assistance choosing the best floor for your sensitivities, budget and area of the house, please contact me for a one-on-one consultation. 

This post covers green non-toxic flooring divided into three categories, starting with the purest options:

1. The Greenest Options (Dark Green)
2. Medium Green
3. Light Green

I recommend all of the products here, some products have affiliate programs and some do not. Upon purchase, I earn a small commission through affiliate links at no extra cost to you.

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1. Greenest Floors “Dark Green” (0 VOC, No Offgassing)


i. Natural Solid Hard Wood 

Naturally finished floors by @wdflooring
@fourboardwoodworks flooring & installation
@thomashartshelby photography

Natural wood flooring is usually my number one choice. It’s one of the purest and safest options. A few caveats for those extremely sensitive:

Wood contains natural terpenes that are safe (and even beneficial) for healthy folks, but do bother some extremely sensitive people. Aromatic woods like pine have higher natural volatile compounds than maple, as an example.

Flooring can contain anti-sapstain chemicals, which could explain why a few people react to wood used in building and not wood in the forest. Not all of these treatments are harmful.

Wood also has a higher possibility of harboring mold than less porous materials. To prevent mold you should make sure your wood has been kiln-dried and kept dry at the store and onsite. In normal conditions, this is not an issue.

Wood Finishes

There are many green 0-VOC options for finishing wood. I used Hemp Oil on my floors, a purest option. AFM Poly BP is another great non-toxic finish.

I go into detail on more options for wood sealers and stains in my post on sealers.

Wood Floor Glues

For subfloor glues, my top pick is definitely AFM Almighty Adhesive which is safe and highly tolerable. My post on Glues has more info.

There are no VOC/HAPs wood fillers by Mohawk and ECOS for the nail holes. I find the standard Minwax wood putty to be too potent. The Dynamic putty pencil is very benign.

Unfinished Hardwood

You can buy solid unfinished hardwood flooring from specialty flooring stores, as well as Home Depot, Lowes and Lumber Liquidators. Lumber Liquidators is usually going to have the lowest price.

These big-box stores have networks of installers.

Prefinished Hardwood

Usually finished with aluminum oxide infused polyurethane and cured under UV lights, these are typically very well tolerated once cured. I consider this to be a safe product even for the chemically sensitive. Test it first. It is close to 0-VOC.

This finish has two main benefits, not having to finish it in house and the finish partially blocks the wood odor.

I have looked over Mirage brand as well as Mono Serra from Home Depot. Bellawood from Lumber Liquidators also uses the UV cured polyurethane with aluminum oxide – they claim low VOC.

Install of Hardwood

Use solid wood baseboards – they come in both primed and unfinished (don’t use MDF).

My post on non-toxic underlayments includes silicone backed paper (for the most sensitive) or Rosin paper.

Nail down installation is less toxic than glue-down. You may need a small amount of regular wood glue on the last piece, or you may be able to face nail.

Best practices for wide planks is to glue and nail. Consider that at the planning stage.

ii. Polished Concrete

non toxic polished concrete floor

If polished concrete flooring makes you think IKEA warehouse, think again, polished concrete can look beautiful and be green and healthy.

The Retroplate system uses “liquid glass” (a modified sodium silicate) and is completely non-toxic and 0-VOC. This option is available across Canada and the US.

Most polished concrete systems use sodium silicate or potassium silicate which are very safe and benign. Polished concrete is vapor breathable which makes it one of the best flooring types, alongside tile, over a concrete slab.

You can do acid stains, add natural pigments, use white cement, or add white sand to Portland Cement to get many different unique and modern looks.

Other concrete sealers

Concrete can also be sealed with topical acrylic or polyurethane sealers, penetrating sealers or epoxies.

A lot of people want to know if epoxy sealers are non-toxic. Epoxy is a two-part sealer, where each part, in theory, comes to a complete chemical reaction with the other. In reality, it’s not that neat. It’s likely to offgas even if it claims 0 VOC.

Eventually, it should come to a complete cure. I don’t advise epoxy over a slab or basement floor, where it’s best to have it be able to dry to the inside.

For a complete review of concrete stains, sealers, and paints, see my dedicated post on this topic.

iii. Tiles

Types of Non-Toxic Tiles:

Marble tile is good in theory. Most of it has a resin put on it at the factory to fill in tiny holes and fissures, and it might have a (chemical) sealant on it as well. The resin seems to cure and be fine for most people, the sealer is not as good for a couple reasons. Look for honed stones you can seal yourself.

A pure slab, or tile, that does not have a glossy finish can be sealed with a natural or low toxin sealer.

Slate is also good, you can find it unsealed like these tiles from Home Depot. Though like marble, a resin is used to fill lines and pits.

Both can be sealed with Meta Cream or walnut oil. Some types of slate and granite are dense enough to not require a sealer.

Concrete tiles have beautiful designs. You may want to ask what additives are in the concrete and test them out for tolerability. I sealed my concrete tiles with AFM Penetrating Water Stop. You can also use tung oil or Meta Cream.

Other natural stones like travertine, soapstone, and limestone are great options for green healthy floors. Always check if a resin or sealer is already applied, and then check to see which natural sealers will work over the stone of your choosing. Honed stones (i.e. not glossy) are the easiest to seal with a natural pure option. Very dense stones like many granite types and some slate do not require a sealer at all (bonus).

Tile Sealers: Budding green companies now make walnut oil and hemp oil that can be used on natural stone and concrete. I have tested the natural oils on slate, light-colored marble and dark-colored marble. Walnut oil is the preferred oil for most indoor stones, as hemp can turn the color, and tung is too thick.

Ceramic tiles have a high incidence of lead in the glaze. Ask for lead test results from the company and do a simple 3M Lead Swab (those are useful on a number of household items, and they are affordable). But to pick up lower levels of lead, you need to hire someone who has an XRF tool.

Lead in Tiles: All ceramic/porcelain tiles should be tested for lead. A client just tested American made tiles that stated they were lead-free, but when tested they showed high levels of lead. So it might be wise to test any glazed tile regardless of origin. And be extra careful when removing them as the lead dust is particularly harmful. Tile over existing lead tiles if possible, instead of removing.

Once you have ruled out lead, ceramic and Porcelain tiles are inert and safe. Plus, you don’t have to seal them. My post on grout and thinset looks closely at the other components used in the install.

Wood-look tiles claim to be 0-VOC even though there is a printed image on them. The glaze seems to block this. I have tested them and I do not detect anything that is different from regular tiles. Wood-look tiles are usually porcelain but can be ceramic.

Glass tiles are inert, but most types are too slippery to use on the floor. Some folks have found a way to use some glass tile types on the floor, but it’s an unusual application and not something I have found available for purchase.

Air Cleaning Tiles

Crossville Tiles have a coating option called Hydrotect. This uses the PCO process to clean the air. A layer of non-toxic titanium dioxide is used to coat the tiles. This reacts with UV light, and just like the PCO air purifiers I reviewed, creates a reaction that can break down some bacteria, molds, VOCs, and viruses. I don’t know how impactful this tile coating will be to the overall air quality in a room. The company does have some reports that show a reduction in bacteria, which may be worthwhile for some folks.

If you read my article on PCO air filters you will remember that some people have a bad reaction to this process. It’s possible that in a high VOC area it creates formaldehyde, or in a clean environment, it can create NOx. I would try out a PCO air purifier before installing this tile, to make sure it works well for you.

This air cleaning technology is also used on wood floors.

2. Medium Green (0 to Low-VOC)


i. Natural Linoleum

Marmoleum, the only natural linoleum currently available in North America, is made from linseed oil, binders, wood flour, limestone, and dry pigments. They are mixed and then calendared onto a backing. It’s got a UV cured sealer on top.

This is the glue used to install it. It claims 0-VOC and does contain mildewcides (typically isothiazolinones). Acrylic flooring glues also typically contain a plasticizer (source).

I found that after one month the odor all but disappeared from the product – though many people say the odor never disappears 100%. I am using this in my trailer. I was surprised and impressed since I don’t normally do well with linseed.

Three Types of Marmoleum

  1. The roll down flooring that is the most typical kind (the sheet) has a jute backing and is glue down.
  2. The tiles (MCT) are also glue down, they have a polyester backing (not jute, and not fiberglass as some websites say) and are slightly more rigid.
  3. The “click” is the same sheet (roll down material) mounted onto a substrate of HDF and cork. It takes longer to offgas, but it has the advantage of not needing glue.

This is one of my top flooring choices, I recommend it often and it looks cool as well. I like many of the colors and the concrete look.

You can use this in wet areas like kitchens and bathrooms if it’s properly installed.

ii. Engineered Wood

Most brands of engineered wood floors now are 0-VOC or close to it, even if they are not marketed that way.

What to Look for

  1. A plywood base/substrate
  2. A stain/varnish that is 0 VOC

The Substrate

Plywood is made with formaldehyde but by the time this product gets to you, it technically is considered cured. They can usually claim that this is no longer offgassing formaldehyde. It’s only the extremely sensitive who should make sure this is good enough.

There are a few brands that use a fibreboard base so check to see what the substrate is.

The hybrid type described below has a PVC base.

The Stain/Finish

Most finishes on engineered wood have no offgassing or close to it. I look for water-based UV cured, which is polyurethane. This usually has aluminum oxide in it and it very close to 0-VOC.

There are also 0-VOC oil-based finishes which are also UV cured. The UV curing speeds up the offgassing so that it is much faster than it would be if you applied it yourself. Both are worth checking out.

Sometimes the stain has a bit of a VOC odor, but you will only know by getting samples yourself, since all brands could qualify for the strictest certifications.

Brands

Kahrs is a top brand that has been marketed as “green” or “eco”. They claim zero added formaldehyde and zero added VOCs. I tested it and found it to be quite good.

Here is my look at their different lines, and here are their test results. With a total VOC level of 50 ug/m3, it’s still not clear to me how three of those five chemicals are not added to the glues or finish. However, that is still an extremely low level of VOCs, and two of the VOCs are terpenes naturally occurring from wood.

The majority of folks do well with Kahrs, but many other brands are just as good.

There are many brands that are good. Lauzon and Home Crafters (from Home Depot!) in Canada. Tesoro, Cali Meritage, USFloors, Whickham, Azur Reserve, and Rockwood, are American brands. There are so many more.

Vinyl-Wood Hybrid

A category of engineered wood that is actually a vinyl/wood hybrid – this has real wood on the top layer and vinyl/limestone composite as the base layer.

In most situations, engineered wood with a plywood base is preferable. But there are reasons to use the hybrid.

This eliminates that pine/spruce/fir odor in engineered wood and also doesn’t have a discernible PVC odor off-gassing that LVP has. In many ways, it’s the best of both worlds.

It’s one of my top picks for a trailer or RV. (More trailer flooring options here).

Brands

1. Cali Bamboo Geowood is one I really liked. It is very tolerable, and for those sensitive to wood, this limestone/PVC substrate (SPC) may be preferable to a plywood base. Plywood will have that odor of pine/spruce/fir and is made with some formaldehyde.

It is formaldehyde-free and it was tested by Green Design Center. I did pick up some offgassing in the stain on the top.

2. Another similar (and inexpensive) wood/vinyl hybrid is Opti-Wood. You can find this at Home Depot (in Canada and the US). It’s well priced, and I did not pick up offgassing in the top layer in the samples I bought. The wood layer eliminates the higher offgassing top layer of vinyl in LVP and it should prevent a lot of the leaching of plasticizers.

3. Raintree is a brand that has a high-quality wood top layer, with some higher-end looks. I have some samples, and like the other brands, the wood layer is very thin. From a distance, it’s hard to tell if these are real wood but underfoot, you can tell it definitely feels like real wood not plastic. The top pick in this category.

Installation

Use floating where possible, not glue down. The Kahrs underlayment is good. My post on underlayment goes into more detail on when to use each type.

iii. Healthy Carpet

For safe, non-toxic carpet, both natural fibers and synthetics can be healthy. If you are interested in carpet, I have a whole post dedicated to this topic that goes into detail on brands, chemical treatments, and how the installation affects toxicity.

I have a separate post devoted to non-toxic area rugs.

Non-Toxic Natural Fiber Carpet

Earth Weave from Green Design Center

1. Earth Weave – wool, no mothproofing, no other treatments, does contain latex. I always prefer undyed wool for the very sensitive.

2. Nature’s Carpet  – wool – contains natural latex adhesive. The dark green line does not have mothproofing and uses undyed wool. The medium green line does not contain natural latex, which for me is a big plus, but it does contain mothproofing.

3. Seagrass – I really like seagrass carpet because of how it feels underfoot. The DMI brand makes one I like that is not dyed or treated with insecticides or other chemicals. It does contain natural latex.

Non-Toxic Synthetic Carpet

1. Home Fresh – One of my top picks for synthetic carpet (PET polyester) with a felt backing. It was extremely low in odor and offgassing. It does contain Scotchguard.

See the carpet post for more details.

This is Air.o by Mohawk (Home Fresh looks similar)

2. Air.o by Mohawk – My other top pick for synthetic, this carpet is very similar to Homefresh. The carpet fibers are made from 100% PET (polyester). They claim it has no odor and is 0-VOC. Some sellers list it as containing Scotchguard treatment.

It has a similar felt padding which is far superior health-wise to typical polyurethane or latex rubber.

3. FLOR – makes carpet tiles which can be arranged as rugs or wall to wall carpeting.

Their regular nylon lines have a different type of offgassing odor than typical carpet, not necessarily less strong, but it did offgas faster.

The Fedora line is made from recycled plastic (PET) and is very low VOC, it quickly approached odorless, in my opinion.

Commercial Grade Carpets

Low-VOC commercial carpet is harder to find than residential. I have reviewed and sniffed a few of the ones that claim to have the lowest VOC levels.

There are wool and synthetic commercial options reviewed in my dedicated carpet post.

Can Carpet ever be a Healthy Flooring?

Because carpet does collect dust, mold spores, pesticides, flame retardants and all types of contaminants and allergens that ride on dust, a HEPA vacuum like the Nilfisk is essential for cleaning.

iv. Terrazzo

Terrazzo is a little complex as there are different materials, resins and sealers involved. But there are systems that are 0-VOC and low-VOC.

v. Laminate Flooring

Most (or possibly all) laminates in North America are now low-VOC.

Look for brands that have certifications, there are many, but GreenGuard Gold is the best certification for laminate.

Most brands can easily meet the other certification levels, so those does not help to distinguish between them.

Formaldehyde-Free Laminate Floors

Most are formaldehyde-free in the core (or more accurately said, no added formaldehyde).

Make sure they are not made with MDF, which is usually high in formaldehyde. Almost all brands are now are made with an HDF backing.

I would go with GreenGuard Gold Certification if you can, as this is the strictest level of formaldehyde allowed (0.0073 ppm), far below any of the other certification levels.

This is “background levels”, there is as much formaldehyde in the outdoor air. This is not the laminate from years ago!

A number of other brands have this certification as well. It’s possible to make HDF without harmful adhesives, but it seems that the formaldehyde has been replaced with undisclosed glues that do still offgas noticeably (possibly MDI glue). It’s wise to check out samples of a few brands.

My Top Brands

Swiss Krono, Home Decorators Collection, and Traffic Master meet GreenGuard Gold and I found them very low in offgassing.

Pergo was also low in offgassing, though I could not tell the age of the samples. They used to have Greenguard Gold certification before they were bought out by Mohawk. I don’t think the glues have likely changed, Mohawk simply doesn’t use Greenguard.

Some lines are “waterproof” – they have an extra component of wax on the tongue and groove parts. I did not find these to be higher in offgassing. I tested all the Pergo lines and they were all similar.

Here is my video review of the brands you can buy at Home Depot, I was impressed.

Home Decorators Collection seemed lower in offgassing straight out of the box, but Traffic Master offgassed quicker – to me it seemed to almost fully offgassed in about a month. Whereas, HDC did not seem to have made much progress at all in a month.

Green Brands of Laminate Flooring?

Brands sold at green supply stores like Eurostyle (by the large worldwide company Krono Flooring) were not able to say their actual formaldehyde or VOC levels, and only cited their certifications, and so they did not provide any information to distinguish themselves from the competition.

Installation

This type of flooring can be floating – it doesn’t require adhesive during installation, which is a bonus. My post on underlayment goes through the choices there.

vi. Zero-VOC Resilient Flooring

Most sheet flooring is vinyl sheet which I find far too high in offgassing. Marmoleum mentioned above is another type of resilient flooring.

Recently though, there are a few very healthy additions to this category.

UPO by Kahrs makes three really great options. Xpression and Zero Tile are made of safer plastics – TPE and polyolefin (which in this case almost certainly means polyethylene and/or polypropylene). No plasticizers and no PVC.

Quartz tile, their stiffer flooring has a base of the mineral quartz and PVC, with no phthalates and no DHEP. It’s virtually odorless, even lower odor than LVP. Nothing like the usual vinyl rolls.

Another new healthy resilient flooring is Shaw Contract’s commercial bio-based polyurethane. It’s made of 90% natural oils (but not linseed) and minerals. It barely has an odor. The backing contains PE and fiberglass and gives off a very slight odor.

You would have to check out the glues as well for each of the floors you are considering.

3. Light Green (Low-VOC)


i. Cork

Cork like wood has a natural odor (terpenes). But with cork flooring, a resin (glue) is used to press and bind all the small pieces of cork together into flat sheets.

I have seen polyurethane glues used which I find to have strong offgassing that persists. Polyvinyl acetate can also be added.

Every cork flooring I have tested is too high in offgassing for me to consider.

In theory, you can heat press cork like they do with some insulation, but this is not how cork flooring is made. That only works with insulation.

An adhesive is also required either to glue it down (and there are 0-VOC glues for this) or, in the floating floors it is usually glued to a fiberboard (HDF) substrate, which has its own offgassing. Though some floating floor brands are cork through and through.

It is finished with urethanes or acrylic which are likely tolerable once cured and are far less of a concern than the glues used to press it together.

Brands of Cork Flooring

I tested Cali Bamboo cork (when they had the type with cork on the top layer) which I found to be the best one at the time. They claim no added urea-formaldehyde (which indicates phenol formaldehyde is added).

US Floors Cork was the second best – this is GreenGuard Gold certified which means the adhesive is almost certainly not formaldehyde. Though the replacement polyurethane glues seem just as high in offgassing to me.

NOVA Cork (38 ug/m3 formaldehyde) and Cancork (no added formaldehyde in the adhesive) smelled very strong to me, and were the strongest of the four.

Here is my Facebook post about the sniff testing of these brands. These floors claim to be green, but the offgassing is higher than I would ever go for, and that’s why they are in the light green category.

I tried the WISE waterproof Amorium Cork flooring in 2020. I could pick up the offgassing clearly. Polyethelene is the main binder here, but it also contains some formaldehyde and BPA. The full Declare label is here. It is GreenGuard Gold.

I clicked two pieces together and put a small amount of water on it. Here are my photos from my test – a small amount of water did go through in between the seams. I personally would not use this flooring in a wet room.

Floors with some Cork

Some flooring that has a cork core and laminate on top can sometimes be referred to as cork flooring even though it has a laminate or plastic top.

Cali Bamboo Silverwood falls into this category, which is cork with a laminate/ceramic top, as well as Woodwise which has a PET plastic (not vinyl) engineered top layer.

Related Post: Non-Toxic Gym Flooring

ii. Bamboo Flooring

Bamboo requires resin or adhesives to hold the strands together, most have a substrate and then a finish. There are many that are GreenGuard certified for low emissions.

This wood is known to be problematic in that it can shrink, expand and do poorly with water/moisture/spills.

It doesn’t do well in high humidity (warp) or very low humidity (crack).

Cali Bamboo GeoCore is made on a limestone-based core which I found quite impressive in how low VOC it was.

The other type that is very solid is the Ecofusion, which is not the typical engineered product – it is 100% bamboo through and through. I look at it in this flooring video here.

Formaldehyde is a typical glue in bamboo flooring. If it doesn’t have formaldehyde it will have isocyanate based glue (like MDI) or soy flour polyamide-epichlorohydrin (PAE) resin. The bamboo is also treated with borates. The finish is usually UV urethane acrylate finish containing aluminum oxide. (Source: Pharos project)

iii. Magnetic Ceramic Tiles

I tested Kablan’s magnetic ceramic tiles. These are ceramic tiles with a magnetic backing. The other side to the magnet is an underlayment that is glued down to the floor.

I found that the magnetic backing components did have a moderately strong smell, though you may not be able to smell them once the floor is installed.

I have a video review of them here. Since the video, they have made these tiles lighter in weight. You may have areas where you want tiles that you can pull up. It’s a cool idea, I quite liked them.

iv. Luxury Vinyl Plank

Luxury vinyl plank (LVP) is much lower in offgassing than people generally think.

I know, most of us think vinyl is one of the worst options.

It is very low-VOC, and most of it is phthalate-free now – though those were replaced with alternate plasticizers. The most common plasticizer used now is DOTP.

There is a huge difference between LVP and sheet vinyl flooring. Sheet vinyl is way higher in offgassing.

However, I do pick up the chemical odor off every brand I have sampled and I do have concerns about plasticizers (which all brands contain), and small amounts of metals (explained more below).

Multilayer LVP

This type has a core (SPC or WPC), vinyl top, and an underlayment. It is click together.

Most of the LVP click together flooring has an SPC (stone polymer composite) core – a mix of limestone, PVC and plasticizer.

Only a few brands have WPC (wood plastic composite), these used to have real wood but now the ones I’m seeing are plastic. They have an added foaming agent, which can be formamide.

I can’t make a generalization about which one is lower in offgassing, it’s been variable.

Should you Consider Vinyl as a Safe Flooring Choice?

This might be one of your first considerations for an RV, and can be considered if engineered wood and laminate floors don’t work for you.

They can also be considered by anyone in the mild to moderately sensitive category.

All LVP brands are very similar there are only three main differences outlined below.

Non-Toxic Brands of LVP

I sniff tested Armstrong and Cali Bamboo brands – both surprised me in how low the offgassing was.

I also tried the brands you can find at Home Depot which I review here. Armstrong and Cali Bamboo are still my top choices.

Cali Bamboo

Cali brand has a limestone backing which is excellent in terms of health and safety (much preferred over vinyl and/or cork backing).

Cali discloses their testing and the VOC levels are extremely low. Here are their phthalate testing results (they are not phthalate-free).

Use a floating floor instead of glue down when possible. You don’t always have to go with the branded underlayment for all floors, but the Cali underlayment is very good.

An alternative to Cali is Tesoro, which also has a limestone backing and they claim it is phthalate-free.

Armstrong

Armstrong has three different thicknesses. The thinnest one (called Good) as shown here, has the least offgassing, however, it’s a glue down floor. “Better” and “Best” are thicker and are click together, and are slightly higher VOCs in my estimation than the thinnest option.

I don’t like the cork backing on the “Best” as the glues in cork are higher in offgassing. All the Armstrong vinyl I have reviewed is phthalate-free.

Home Depot Brands

Out of the Home Depot brands, Traffic Master was the thinnest one. Lifeproof to me seemed to have the lowest offgassing, though the underlayment odor was strong to me.

Home Decorators was similar to Traffic Master. All brands sold at Home Depot, Lowe’s, and Lumber Liquidators are phthalate-free.

THREE Things to Ask (when choosing LVP floors)

1) Double-check to make sure it’s virgin (not recycled) vinyl.

2) Look for Phthalate-Free

3) You might have a preference for SPC over WPC.

Phthalate-Free Vinyl Flooring and Replacement Plasticizers 

Phthalate-free brands are preferable – which most are now. If phthalates (also known as ortho-phthalates) are not used, other plasticizers will be used instead.

Replacement plasticizers include DOTP (also called DEHT) which is the main one used right now. Some may contain benzoate ester (Source).

Toxic Metals in Vinyl Flooring

Organotins (a form of tin) can be used in the top layer. Antimicrobials can be used, usually in the underlayment. I have seen various types, including silver. EHN found the heavy metal cadmium recently in vinyl floors (probably recycled ones, they say).

It’s important to avoid recycled vinyl. Lumber Liquidators and Floor & Decor banned recycled vinyl to avoid the associated toxic contaminants like metals and halogenated flame retardants.

Lead, cadmium, chromium, and mercury can be present and are only officially limited (not banned), as far as I have seen, by Floor and Decor.

Though antimony, bromine, and lead have been virtually eliminated according to the latest study.

Offgassing of VOCs in Vinyl Flooring

Sheet vinyl is higher offgassing than LVP. I have seen this is the 0.5 – 5 mg/m3 Total VOC range, whereas vinyl click will be less than 0.5 mg/m3.

It gives off small amounts of aldehydes as well as a couple of other VOCs. These are less of a concern to me than plasticizers which are a longer-lasting and more concerning class of chemicals.


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Cost Comparison of Green Flooring 2020 (USD)

  • Wood $8 – 10 / sq ft including installation 
  • Polished concrete is $8 – 15 / sq ft for residential
  • Stain and sealed concrete – materials $1/ sq ft (unless you are pouring the concrete or have lots of prep)
  • Tiles are usually $8 – 10 / sq ft but it depends on the tiles (tiles come in a wide range of costs) and prep of subfloor/installation difficulty
  • Marble floor material costs are $10 – $20 / sq ft (specialty marbles can go up to $40 per square foot). Labor is an additional $3 to $7 / sq ft
  • Kahrs Engineered – Materials $5 – 12 / sq ft, labor $3 – 10 / sq ft
  • Home Depot Brands engineered wood start at $3 / sq ft for materials 
  • Marmoleum – Materials $4.50 – 5 / sq ft, labour $1 – 4 / sq ft 
  • Wool Carpet J Mish $4 – $8, Earthweave $6, Nature’s Carpet $7 / sq ft
  • LVP:
    • Cali bamboo – under $3.30-5 / sq ft, labour about $3-4 / sq ft for click
      Armstrong starts at $1 / sq ft for materials
      Home Depot brands $1-3 / sq ft
  • Laminate:
    • Home Decorators Collection $1.30-2 / sq ft, labour $3-4 / sq ft
      Trafic Master $0.50-2 / sq ft
      Pergo $2-3 / sq ft
  • Cork $8-10 / sq ft including installation
healthy home build consult

Corinne Segura is a Building Biologist with 6 years of experience helping others create healthy homes.

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

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Filed Under: Healthy Building, Healthy Interiors Tagged With: Healthy building, healthy interiors, mold prevention

Healthy Home Building Consultant

September 9, 2019 by Corinne 4 Comments

I have been helping folks create healthy homes for over 6 years now!

A certified Building Biologist Practioner, I began this journey with the build of my own tiny chemically safe house, the place in which I started to recover from mold illness and severe chemical sensitivity.

My main expertise lies in materials available in the US and Canada.

Healthy Home Consults are for you if:

  • You own or rent a house, apartment or trailer
  • You are building or remodelling
  • You live with environmental sensitivities, allergies or asthma, including the most severe MCS
  • You have children or are expecting and want to provide a healthy home for them
  • You are a builder, architect, designer or developer and want to collaborate
  • You are healthy and want to minimize exposure to toxins to prevent health issues

Areas I can assist you with:

Healthy Material Selection

We will go over your specific sensitivities, needs, and level of toxin avoidance, and you will come away with a list of products to use in your build or renovation.

This may involve self testing materials for your own reactions. If you don’t have reactions (or obvious reactions), I will use your level of toxin avoidance to recommend products.

You will come away with pros and cons of materials you might have read about.

I will take into consideration the system as a whole, so that your moisture management system is intact and point out areas that are mold prone.

If it’s a new build, you will come away knowing the typical steps to choose an architect, builder, materials and job site supervisor.

I can work with your team from start to finish if you need.

I help healthy folks and sensitive folks who range from those with mild allergies to those with extreme chemical sensitivities.

I’m not just analyzing the SDS and what the manufacturer is telling us about what’s in it, I’m also using industry knowledge to suggest what additives are typically used and undisclosed. And I use my experience and that of thousands of chemically sensitive folks to choose the safest products.

Remediating Chemical Offgassing

If you have an odor or chemical offgassing we will troubleshoot the cause and what can be done about it.

You will come away with strategies to then implement. These might be removing materials, sealing, cleaning with special cleaners, using ozone, choosing the right air purifier, putting in air exchange, using positive pressure and “baking” a house.

If we are having trouble figuring out the source, I will recommend a number of low tech and high tech ways to figure it out.

Healthy Home Audit

You will come away knowing how to make your current dwelling a healthier home.

We might look at one room like a bedroom and top to bottom make it a healthier healing space, or we might look at how to find testing for VOCs, radon, and mold.

Topics include: which materials should be removed and replaced, helping to select the best air purifier for your needs, choosing water filtration systems, choosing furniture, beds and other household items.

In Person Inspection

This can be done in person in the south Vancouver Island and Victoria, BC area. Update: During COVID I will not be conducting in-person inspections.

I use my nose and reactions as well as knowledge about problematic building materials to asses problem areas in your home or to help you find a new healthier home to buy or rent.

Buying, Building a RV, Trailer, or Tiny House

If you want to buy, build or renovate anything on wheels we will look at which ones are best for your chemical sensitivities and which ones are more mold resistant.

If you are buying, you will come away with pros and cons of different brands as well as different strategies (buy one that holds up and let it offgas or buy one and trade it in when it goes moldy).

If you are building or gutting a trailer we will look at typical problem areas that done wrong and are prone to mold and I will refer you to a building science expert if there is something I can see will likely go moldy.

You will also come away with which low offgassing materials will be best to use.

If building a tiny home on wheels I can walk you through the process of finding an architect, builder, choosing materials and supervising.

Camping and Simple Shelters

Whether you need to camp out of necessity or purposefully in order to unmask and bring down sensitivities, we will get your camping set up together.

You will come away with the confidence to camp even with severe sensitivities and limitations.

You will know which types of tent material to consider as well as what other gear you need.

If you cannot tolerate any ready-made tents we will look at custom making a tent or shelter out of almost any material you can think of – hemp, cotton, non-offgassing plastics (both hard plastic and flexible rolls), metal, foam, and wood.

Mold Avoidance Consulting

For a detailed overview of what I offer with mold avoidance coaching, see this post dedicated to that topic.

Booking and Contact

 

Urgent appointments on weekends and (US) holidays can be booked here.

Note: Topics I Don’t Cover

  • Remediation of mold, pesticides, lead, radon and asbestos (consult with specialists in those fields).
  • Pest control choices (consult with a non-toxic pest control specialist).
  • Mechanical systems: HVAC, appliances, electrical system concerns, and water heaters (consult with experts in the required mechanical field).
  • Building science advice (should be provided by an architect, engineer, or other building science expert).
  • How long does x take to offgas. Unless it’s a simple chemical that has been studied, it’s not likely someone has the answer to this. I have sniff tested many products myself and have experience from thousands of chemically sensitive folks, but I don’t have an answer for every product.
  • EMFs/EMR
  • Materials outside of North America – Evaluation of building materials, homes, and products outside of Canada and the US.
  • Recommend a builder – I don’t recommend specific builders including tiny house companies. I do have some builders, designers, and architects on my resource page and can guide you through the process of finding a builder. More on why I don’t recommend builders here.

Filed Under: Healthy Building Tagged With: Healthy building

Tiny Homes & Shelters for the Mold & Chemically Sensitive

September 4, 2019 by Corinne 18 Comments

Updated in Summer 2020

Related posts:
1. Regular-sized non-toxic prefab homes
2. Mobile homes on wheels for those with sensitivities
3. Emergency shelters for those with sensitivities

Simple, Small Modular and Custom Homes for those Sensitive to Mold and Chemicals

These are small and tiny houses (not on wheels) that are suitable for those with extreme sensitivities to mold and or chemicals.

Not all materials will work for all folks, that is why this article features everything from all wood, to all plastic and all metal homes.

I have natural materials on the list as well, like hemp and concrete.

These small houses are ideal to create a healing space away from conventional housing that is so prone to problems.

This post contains an affiliate link to a home sold on Amazon. This home was on this list before they starting selling through Amazon. Upon purchase, through affiliate links I earn a commission at no extra cost to you. This post is not otherwise sponsored by any of the companies.

For individual help choosing the best small home for your needs, or a review of a tiny house company not mentioned, you can contact me here for a consult. 

1. Passive Home Tiny Homes

https://unityhomes.com/our-designs/nano/

Besonwood is a high-quality passive home custom prefab company. Their custom Thoreau Cabin home is 150 sq ft. The owner chose the stone facade but that is not a typical facade. They are custom homes so they can build any size.

Their predesigned wing is called Unity Homes. Their smallest house “Nano” (pictured) is 477 sq ft. Nano Shell packages start at $65,000, and for a complete house, it would be roughly $150,000.

They are wood framed with passive house design, made to high standards. This would not work for those extremely sensitive to offgassing as their walls include OSB and engineered wood framing.

The insulation used is Rockwool and cellulose in the model I saw (they have different wall systems to choose from).

This is a house that mold sensitive folks should consider due to their high-quality design, high-quality factory-built, and indoor factory conditions. This is at the top of my list for a reason, I would build with this company.

You still have to have planning and supervision on the site prep, foundation and the installation of the prefab components. Every detail matters for mold prevention.

2. All Wood Prefab

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The Holz100 homes come in all sizes from very very tiny, small and large.

The walls, floor and ceiling are all wood, no glue, no nails. The roof will not be all wood, there will need to be another roofing material there.

I have a more in depth review in the general prefab post.

I think this house is very promising but needs more investigation. If you tolerate wood there is nothing else in the interior.

To hit codes you will need to put exterior insulation on it. Exterior foam insulation would also be a fool safe method to prevent possible condensation within the air pockets of the wood wall. That is how I would detail it for mold prevention. This would make it quite pricey.

$35,000 BASE PRICE (CAD) for the 93 sq ft little module.

3. Metal Yurts

http://cleanairyurts.com/our-yurts/yurt-homes/

The metal yurt from Clean Air Yurts is 18 ft in diameter. The shell is made of galvanized steel coated in zinc. The door is metal as well.

You would need to build a foundation and choose materials for the exterior and interior, provide insulation and wiring and plumbing (if desired).

Though you could just leave it as a steel structure. The yurt can be assembled in one day and can be taken down and moved if needed.

Metal walls are very difficult to insulate in cold climates. In a cold climate, you would need a perfect airtight insulation. See the section at the end about exterior vapor barriers in cold climates. Metal houses can work well in places where you don’t need insulation or where you don’t use heating.

In some very dry climates, you can get away with loosely fit foam insulation but you would want to be able to check on that and make sure there is no condensation behind it.

The cost of the metal yurt is 10K

Grain Bin Home – Another Yurt Like Option

These Grain Bin Homes are also 18 ft in diameter and made of galvanized steel. There is room for a loft and it has louvers that can collect rainwater if desired. Other options include solar panels.

It does not come with options for interior/exterior or foundation, so those would be up to you.

The homes are around 10K but there is a big discount for non-profits who are purchasing them.

Same as above section regarding metal walls – tricky to insulate in heating climates.

4. Wooden Treehouse

From Out N’ About, a company that rents out treehouses, sells plans and parts, this 16′ Treezebo Hexagon could be a great non-toxic home.

The plans for the treehouse are $450 and that includes a 3-hour consultation. The metal parts are $2000-2500 and the wood would come to around 5-10k, not including materials for wiring and plumbing.

I like this simple option if you don’t need insulation. Using a rot-resistant wood and no need to worry about the foundation type simplifies everything here.

This can be a mold preventative option.

5. Arched Cabins

The basic kit for Arched Cabins includes floor plates, ribs, ridge beam, standard R13 insulation, Super Span Roof Paneling, trim and fasteners needed to assemble the cabin.

Arched Cabin kits do not include the foundation, installation, interior, end caps, delivery.

What I like about arched cabins is that there could never be any leaks with this one-piece roof/siding.

In this design, you can use spray foam insulation (with or without rigid foam) without worrying about exterior leaks getting in behind. Spray foam, while it does offgas, is a vapor barrier and the best bet for insulating metal walls in heating climates.

Either closed cell (2 part) spray foam is used to form an airtight vapor barrier in any climate where you heat, or not quite as foolproof is rigid insulation installed with canned (1 part) spray foam).

This is a great system for preventing mold. You do not want permeable insulation against metal in any heating climate.

The large overhangs are also superb protection from rain over the windows and doors on the ends.

The 12×12 kit is $2400. This is a simple, mostly metal kit that you could then customize to be chemical-free on the inside. 

You can see a video tour here and you can check one out on Airbnb.

6. Plastic Domes

These cool Intershelter domes are easy to transport and assemble and have a lifespan of 30 years.

The larger domes are made of a fiberglass composite material that the company says does not emit an odor. Some sensitive people say fiberglass needs some time to offgas (1-2 years or more) and others find it ok fairly soon after production. 

The small domes are 14 feet and are made of ABS plastic, which is a really safe plastic (the same plastic the LEGO is made of). This one they say has an integrated foam component.

I would look closely at the details on the panels that have integrated foam. You would want to make sure this is not likely to leak.

If this is done well this would be much easier than trying to put foam insulation on the inside of the one-panel fiberglass domes yourself.

The integrated foam would be ideal for heating climates (cold climates).

The domes start at $7,500 for the 14′ model in 2017.

Installing foam in the larger domes with an exterior vapor barrier is not simple in heating climate. If you are in a tropical climate this might be ideal.

A similar dome, the Intergalactic, is also fiberglass, and the insulation is integrated.

7. Plastic “Lego” Home

EverBlock makes plastic blocks that fit together like lego. You can make a simple structure out of these.

It’s a safer plastic than fiberglass that is much more tolerable for the chemically sensitive.

8. Plastic Module Homes

coodo.com

There are a few designs that are using metal framing with a plastic body. I find this design extremely promising.

The Coodo above is made in Germany and can deliver all around the world.

A similar company, AluHause is American, with a show house in Palm Desert.

The downside is that fiberglass does offgas and won’t work for many sensitive folks, at least not right away.

Both have the potential to be very waterproof and mold resistant designs. Neither one gives too much away on how it’s built exactly, so we cannot evaluate it in great detail.

Just like when looking at larger prefabs you have to go through the reconnaissance process outlined here.

The Coodo is 61K British Pounds for the base model.

Another similar model is the Haus.me which I go into more detail on in the prefab article. This one looks to be a different type of plastic, not fiberglass, though they don’t say which type. They claim that it doesn’t offgas.

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Haus.me mOne 2019 Zombie proof house. Completely self-sustainable off-the-grid intelligent Home.

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9. Simple Wooden Cabins 

Solid wood very basic wood cabin


Leisure Cabins bare bone wooden cabins are made of solid wood. I see some OSB in the subfloor but that could be avoided. Opt for solid wood for the roofing as well.

There is no insulation so they would be difficult to live in in extreme temperatures.

It does not include roofing shingles and roof prepping, stains, railing, foundation and deck or windows. You do your own wiring, plumbing, and systems as well.

This version is a thin wood wall, not very warm. And when you start to insulate something like this you start to get into a complicated design.

In that case I would prefer to go back to a prefab like the Unity Homes on this list which already has a well thought out wall system, or even design a house from scratch.

Trying to make one of these kits work with insulation is working backward from a plan that won’t likely come together in a mold preventative way in climates where heating is used.

It is $6500 CAD for a 14 x 14 foot cabin. They are produced in Canada. 

Amish Built Wood House

From Backyard Buildings in Maine, these tiny houses are a good deal. They are custom built. This one pictured is from a member of the EI groups on Facebook and I have her permission to post about it.

The house is made of local wood, non-fiberglass insulation, low VOC adhesives, a woodstove (but you could use electric heat), wired for on-grid (but can do off-grid as well), cedar siding, metal roof, and plumbing.  

This does become a complicated system to design when you add insulation.

When I tried to work with this company, it was difficult to communicate with the builders (because of lack of technology/being Amish). They were mixing some traditional building with some more modern techniques like adding exterior foam insulation and I didn’t think it was mold-safe or detailed right.

They can be moved though they are not on wheels. This one is 400 sq ft and was only 14K. I would only get a shell if buying something like this so that you can detail it yourself.

When buying a shell you also want to make sure it has a rainscreen if you are going to insulate it, otherwise you won’t be able to build that out properly.

A Traditional Log Cabin

https://www.montanamobilecabins.com/projects-updates

For a thicker wood wall look at a company like Montana Mobile Cabins. This true round log cabin does not use insulation.

I much prefer this simple design than to try and insulate a wood framed cabin. This is a much safer bet for mold prevention.

It’s not perfect as I have heard of condensation in log cabins, I would consult with a building science expert on how to make this work in your climate.

Prefab Square Log Cabins

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On a perfectly warm summer's night, what would you do if you had a relaxing porch all to yourself? Would you paint, read, type? #cottagecountry

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I like the thick square logs too. I like that they would fit together well. In theory this might create a more airtight assembly which might help prevent moisture and condensation issues.

Confederation Log Homes above makes custom prefab log homes with square-cut logs. The company has been around for a long time.

This is the first log home company I would look at due to their extensive experience.

10. A Metal SIPS House

The Nomad Cube 

The Nomad Cube is a promising little metal SIPs house. It can be built out to be very non-toxic.

Metal SIPs make up the main walls and roof of the house and are made from laminated steel-EPS white styrofoam-steel. They are essentially 0 VOC and extremely resistant to mold as long as the panels stay laminated together and assuming there are no leaks into the panels.

The smaller Nomad Micro has been redesigned since I originally wrote this. That one is no longer a SIPS house.

The Nomad Cube costs $38,800 USD. It is 13 x 13.

You need to add: shipping (From Vancouver BC), platform/slab/or piers, installation, wiring, heat, plumbing, hot water heater, roofing membrane, interior walls, baseboards, shower door, ladder/stairs, fridge, range, and hood vent.

My most sensitive friend tested the SIPs and thought they were good. It is possible to complete the interior with non-toxic materials.

The basic design of this house is metal framing with metal SIPs. It appears in one of their videos that there is plywood in the base, which I would change.

You will need to have a building science expert review this design and help with the details along the way.

I consider this one of the most promising designs here. It’s the first option on this list I would look into for something really small and simple.

Metal SIPS homes work really well for mold and chemical sensitivities.

Make Your Own SIPS House

You can also make your own SIPS house easily and fast. This one below is made with Structall Building Systems panels. Another brand that I have seen sensitive people use is Permatherm.

These are also metal-EPS foam-metal and have an internal locking together system that allows them to quickly snap together.

In this design the panels are fully structural elements, there is no additional metal framing. The panels make up the walls and roof.

To create a long term structure you would use siding on top of the SIPS and pour a cement slab to the same standards that you would use on a house.

But quick and dirty, you can throw up these panels fast and get away without siding if you don’t need it to last forever.

This is the fastest and safest (for both mold and chemical sensitivity) option on the list.

Review of Boxabl SIPS House

The company Boxabl has created a metal SIPs house that has caught a lot of folks’ attention.

The main reason it has gone so viral is that it promises it all – fast, easy, cheap, resilient, and healthy.

First, is it good for chemically sensitive folks?

Yes, the basic structure of steel/foam SIPs is very safe for those with chemical sensitivities. That part has practically no offgassing.

They also use MgO board on the interior surfaces which is generally safe for most people with MCS. It’s not clear how that is attached, it’s likely glued on, which could be a problem for offgassing.

The flooring appears to be glue down vinyl, though they have described it in different ways. The countertops and tabletop are laminate. And the interior cabinetry is conventional. These three elements will contribute to offgassing of some VOCs, plasticizers, glues, and formaldehyde.

At this time it cannot be customized and it includes all the interior finishes other than the bed and sofa.

Even though it would be quite easy to choose a healthy floor and cabinets, it would likely be difficult to remove the already glued down vinyl.

Is it a mold preventative design?

In general, metal SIPS are very resistant to mold because as long as the wall remains laminated they are immune to condensation problems. The waterproofing will depend on how well the seams are connected.

There are a number of concerns I have with this house:

  • There is a clear negative lap at the bottom of the first piece. It’s not just an exterior trim detail, it’s integral to the design. I don’t see how you would not always be battling water pooling up and soaking the wall.
  • It’s nice that it unpacks quickly into a full livable house but how are all those seams waterproofed? I do not think we have enough information on that right now.
  • Because it’s done almost entirely in a factory we would need to see a detailed factory tour to see if this is a good design (the company does not yet have a full-sized factory and is still raising money). There are so many details I would want to see including how the windows and all seams are waterproofed.
  • The house, like all prefabs, needs to be seen in person, especially during installation to see if there are any vulnerable to water areas. Because this company does not have a show house and is not in full production yet, it’s highly unlikely you will be able to see one any time soon. My prefab post goes over the due diligence needed here, and with this house, we don’t have enough information to even do the due diligence.
  • MgO and steel have not gone well together in the past. In Denmark, massive problems were caused when salts naturally leached out of MgO and corroded the metal in the buildings.
  • The website says that Boxabl “doesn’t use lumber or sheetrock” and in an email they said “we do not use wood or materials that can rot or mold”. But in multiple videos, wood appears to be the framing of the edges of the SIPs. Hidden wood in a metal-based house is a problem in my books.

Is this a reliable company?

Still in development

Well, I don’t think we know if this is a reliable company yet. As I discuss in my general prefab post I never go with the prototype of a prefab. They commonly have problems.

There could be situations in which we know a lot about the company, the construction details, and the testing of the prototype, but I don’t see enough information here to be confident.

The company needs to raise 10 million dollars to be in full production, and right now they are still raising money. They are not yet at production stages.

Inconsistencies

On the fundraising page it says “early investors get a discount”. When someone asked what the discount is they responded “It is possible there will be a discount. We haven’t announced it yet.”

In one of the videos, the rep states that you could install this without a foundation or permit. That sounds like very ill-advised advice.

It does not seem like the reps actually know what the floors are made of.

11. Hemp House

Hemp House Pods – a simple 8 x 12 structure meant to qualify as an ADU (without a permit) is made from hemp and a wood frame. Hemp may be mold resistant in certain climates.

I would have this reviewed just like all the others. I would use huge overhangs and I would look more closely at a foundation type that does not wick moisture up.

The cost does not include plumbing, electrical or the deck.

The houses are 15K and they say they go up in a week.

12. Concrete AirCrete Dome

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I reviewed the AirCrete dome for mold resilience and I have a few thoughts on it. (Note this is different from AirKrete with a “K” insulation, though it’s a very similar material).

AirCrete domes are made of a mix of concrete and a foaming agent. You can use a natural dish soap like 7th Generation.

They were originally used in tropical settings and I do think they might this is simpler in climates that don’t require heating.

Mold Preventative Design of the Roofs

I do not like any of the designs that have multiple domes coming together creating valleys where water will not drain well. In some designs, debris is even accumulating in those valleys. I would only do single domes with as steep of a slope as possible.

No valleys where water and debris collect and soaks in. This is always best practice for mold prevention in houses.

The steeper the slope the better it will shed water.

The Challenge of the Exterior Coating Creating a Vapour Barrier

The exterior is coated with waterproof exterior stucco and then acrylic or similar concrete sealer.

The coating would have to be waterproof which creates a dilemma in heating climates.

If it’s waterproof that is usually an exterior vapor barrier, which can cause condensation and mold in climates where heating is used. This is fine to use in climates where only cooling is used.

I might put this whole structure under a second rood, like a carport (or a souped-up metal roof like this house has). That way you don’t have the conflict of the need for a waterproof but also breathable sealant on the exterior of the dome.

You may also consider a sealer that sheds water but is breathable – a layer of concrete stucco sealed with sodium silicate might work. Just like polished concrete which is vapour breathable but should shed water. Consult with a building science expert to work this out.

Can Concrete go Moldy?

Conventional wisdom is that concrete cannot mold because it’s not organic. As a mold sensitive person, I would say every basement, most slabs, and almost every concrete building in the tropics shows otherwise.

Mold can grow in anything porous, I have found.

Humidity Control is Required

Climates that are hot and humid should use AC or a dehumidifier in any concrete building. AC acts as dehumidification.

It can take 2 years for concrete to fully dry and in humid countries that don’t use AC, concrete goes musty fast.

Many people might not notice this low level of mold but I can smell it and mold sensitive people do often react.

I’ve stayed in many simple concrete builds in the tropics.

Slab Must be Detailed Right for Mold Prevention

It’s also incredibly important to detail the slab right for mold prevention. Slabs are very prone to going moldy in all climates and are rarely detailed properly.

Because slabs are made of concrete and the dome is concrete you also have to take extra precautions with the slab and site details to not have wicking up of water from the ground up through the structure. This could easily happen in rainy climates.

The final flooring over any slab also needs to remain breathable to the inside in best practices for mold prevention. If the slab does take on water through wicking or through water coming in through the sides it needs to dry up.

Only polished concrete, tile (including stone tile), or earthen clay floors should be used as the final floor.

Does the AirCrete Dome Work for Extreme Chemical Sensitivity?

I think this dome would work for many people with MCS.

Admixtures are used in the concrete, you would want to check those out.

The foaming agent can be a non-toxic soap, if you tolerate one of those.

The interior can be finished with natural plaster which does not contain additives.

The exterior finish needs to be looked at carefully, synthetic stucco might not work for everyone who is chemically sensitive. That won’t work in most heating climates anyway. Sodium silicate is considered safe for the chemically sensitive.

The slab would have the same concerns as all slabs. You don’t have to use rigid foam in the slab in many climates, but you do need a thick vapor barrier like Stego. It needs gravel underneath and proper grading.

A polished concrete or tile floor works well for chemical sensitivities.

You can find the workshops and the tools needed to create the concrete foam mix at DomGaia.

13. Container Homes

I have not been a fan of container homes in the past because the exterior metal envelope creates a really tricky situation for condensation is every heating climate.

More on that below, but if you are somewhere where you only use AC or no heat or AC this can be just fine.

When I saw that a company is making exterior insulation for shipping containers this changed my mind on the topic. The foam contours to the container and insulating it on the exterior eliminates the condensation issue.

You will still have to detail around the window and doors, and make the steel envelope airtight (I would try to weld all seams) but I really like this idea.


A Note on Exterior Metal and Fiberglass Shells and Mold Prevention

A prefab house that has a metal or fiberglass shell that does not have a rainscreen system is extremely difficult to insulate in most climates where houses are heated. This includes container homes.

“In a cold climate during the heating season, moisture vapor inside a building is driven outward into exterior walls. When it reaches a surface that’s below the dew point, the vapor condenses into a liquid.” (source).

In this case that “surface” where moisture in the air condensates is that metal or fiberglass shell.

To try and work with this problem you need airtight insulation. This could be 2 part closed-cell polyurethane spray foam insulation. This offgasses too much for most people with chemical sensitivities. It also causes the challenges of exterior leaks going undetected. Arched Cabins has a nice design because there are no seams or permeations.

The second strategy is to use rigid foam insulation and make it airtight. This is also tricky. Foam can be taped or sealed with caulking or 1 part canned polyurethane spray foam, but it’s difficult to keep it airtight. And any gap of air behind the foam can have air with enough moisture to condensate in some climates.

Mold Preventative Design

Options:

  1. In heating climates, it’s easier to have a well-designed wall system that has the proper air barriers (likely no vapor barrier), and a rainscreen – in short, built like a regular house with all the complexities of the wall system but with great attention to design and execution of detail.
  2. A monolithic wall – I tend towards simple buildings that have fewer areas where mistakes can be made. Monolithic walls (a single wall, made of one solid material) is easier in this sense. Log cabins, solid concrete walls, and solid earthen walls are examples. This doesn’t mean they will work in any climate and are foolproof. You still need a building science expert (like an architect) to design the system as a whole and make sure that the wall type is properly designed and executed and well maintained.

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Corinne Segura is a Building Biologist Practitioner with 6 years of experience helping others create healthy homes.

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Filed Under: Healthy Building, Mold-Free Building, Tiny Homes and Trailers Tagged With: green building, prefab, tiny homes

Chemical Offgassing from Pressed Wood and Laminated Wood Products

September 3, 2019 by Corinne 17 Comments


A Guide to Choosing Pressed, Engineered and Laminated Wood Products
– Their Formaldehyde and VOC Levels

This post will cover pressed wood and laminated wood (engineered wood) products used in building, and in household items like furniture and doors.

We are going to look at formaldehyde and other adhesives used and what do they offgas. I will also note which wood types are commonly used.

This is going to be the adhesives used in the US and Canada. Europe will be similar. Other parts of the world may use different adhesives.

This post contains affiliate links to relevant products that I use and recommend. Upon purchase, I earn a small commission at no extra cost to you.

Adhesives used in Engineered Wood Products 

MDI methylene diphenyl diisocyanate – offgasses methylene diphenyl diisocyanate, though the companies claim this cures into a polyurethane.

PF Phenol-Formaldehyde – The change to CARB 2 regulations forced most furniture/cabinet companies to move to phenol-formaldehyde. The offgassing is much lower and in many products comes to a complete cure in a short amount of time.

UF Urea Formaldehyde – This is the type of formaldehyde that offgasses at higher levels and for longer. When you think of furniture or flooring that is offgassing for many years it was likely made of urea-formaldehyde. Try and avoid this type.

NAUF No added Urea Formaldehyde, essentially means PF is used.

NAF No added formaldehyde, this means no formaldehyde is added to the product. They cannot be called formaldehyde-free because wood naturally contains formaldehyde. No added formaldehyde products are often made with MDI or “soy-based glue”.

Soy-Based Glue – Soy-based glue is not just one formulation. They use soy protein mixed with polyamidoamine-epichlorohydrin (PAE), isocyanates and aldehydes. (From the coinventor of the adhesive for Purebond Plywood). This one is called soy-PAE. A similar type of soy-based glue that may be used to replace formaldehyde in MDF and particleboard is a amine-epichlorohydrin adductt/soy protein/isocyanate (source).

Product Certification Formaldehyde Levels:

CARB II – Formaldehyde Levels

CARB II is a standard set by California for products sold there, but most building products across North America comply with this requirement.

Products that fall under this standard include hardwood plywood, medium-density fiberboard, and particleboard – these are pressed wood products sold for indoors.

It does not include exterior sheathing products like exterior plywood (softwood plywood) and OSB.

CARB II Formaldehyde Limits are:

Hardwood Plywood0.05 ppm (parts per million)
Medium-Density Fiberboard (MDF)0.11 ppm
Thin MDF0.13 ppm
Particleboard0.09 ppm

E-0 E-1 and E-2 European Formaldehyde Levels 

E1 certifies that boards release less than 0.1 ppm (parts per million) and for E2 boards 0.1 ppm and 0.3 ppm. E0 is 0.07 ppm

GreenGuard and GreenGuard Gold Formaldehyde Levels

GreenGuard 0.05 ppm (parts per million) formaldehyde and GreenGuard Gold 0.0073 ppm formaldehyde.

How Much Formaldehyde is Acceptable for those Avoiding Toxins?

How do you interpret these levels

Formaldehyde is naturally occurring in wood, plants, animals (including humans), and therefore in the outside air as well.

In fact, wood has a level of natural formaldehyde high enough that if you made a house completely out of wood, you could go over some recommended indoor formaldehyde levels.

Formaldehyde is also produced by human industries, adding to the natural levels in outdoor air everywhere.

The major sources in urban air are power plants, manufacturing facilities, incinerators, and automobile exhaust emissions. Source

Formaldehyde Reference Levels

LevelReference
0.0002-0.006  ppmRural and suburban outdoor air (source)
0.0015-0.047 ppmUrban outdoor air (source)
0.0073 ppmGreenGuard Gold levels for products
0.020-4 ppm Average levels in conventional homes/indoor air (source)
0.04 ppmCanada long-term exposure 8- hour average exposure limit
0.05 ppmGreenGuard levels for products; CARB target level within a home
0.08WHO guidelines for exposure
0.10 ppmUpper limit for residences ASHRAE, EPA,  short term exposure limit
Level at which individuals have reported symptoms in studies
Health Canada short-term exposure 1-hour average limit
0.50 ppmOSHA 8-hour time-weighted average (TWA) action level workplace limit
0.80 ppmLevel at which most people first detect odor
56 ppmPAC-3 (Protective Action Criteria), AEGL-3, 60 minute Acute Exposure Guideline

Wood Products & Adhesives

Plywood (Interior and Exterior)

Which Chemicals does it Offgas?

Exterior plywood

Exterior grades of plywood are used for roof sheathing, subfloors and roof decking.

Exterior grades of plywood is made with phenol-formaldehyde as the binder/glue. Phenol formaldehyde is the least toxic type as it offgasses less and it ofgasses faster.

Exterior plywood can also be called structural plywood or softwood plywood (SWPW).

Type of wood:

It is made of softwood, usually fir (or spruce, pine). In Canada, Douglas Fir Plywood (DFP) (can have up to 21 other species of woods in the inner plies), and Canadian softwood plywood (CSP) may have balsam poplar, trembling aspen and cottonwood.

Formaldehyde:

When the American Plywood Association (APA) tested formaldehyde levels of new exterior plywood they started out below 0.1 parts per million (ppm).

But “emissions rapidly approached zero as the panels aged. In fact, the levels were so low and so close to the ‘background’ levels in the test chamber that is was not possible to measure them accurately” source APA.

While the APA would not say exactly when the PF levels approached 0 or close to it, this is the study that changed my thinking on avoiding plywood in a new build.

For most people, exterior plywood in a build will be sufficiently offgassed by the time the building is complete.

Testing your reactions

If you are extremely sensitive you should test out plywood when new, after a few weeks and after 2-3 months of airing. You should also compare that to OSB, to see which is better for your health.

I generally prefer plywood. My post on sheathing goes into more detail on alternatives if you need to avoid both plywood and OSB.

CDX plywood

CDX is a type/grade of exterior plywood used for sheathing with an Exposure level of 1 other types ending in X are also made for the exterior.

Marine-grade plywood

In the US the marine-grade plywood I’ve seen contains PF, but they can use other glues as well. This is not a specific type of plywood in Canada.

Grades of Plywood

These are grades of Plywood in the US. And here are grades of plywood in Canada.

Pressure-Treated Plywood

Pressure-treated plywood is commonly is treated with Alkaline copper quaternary (ie copper and quaternary ammonia) (ACQ). Copper Azole (CBA) is another type, which contains copper, tebuconazole, and possibly boric acid.

Though some wood is still treated with chromated copper arsenate (CCA), this is not commonly used in residential buildings.

Interior Plywood

Interior grades of plywood were often is made with urea-formaldehyde as the adhesive. Urea-formaldehyde (UF) offgasses more and for longer.

Now, phenol-formaldehyde (PF) is more standard. Interior plywood is often called furniture grade or hardwood plywood. You will want to make sure your furniture is made with PF not UF or with NAF glues.

Interior plywood is made of hardwoods (usually) of various types, though it can be made of softwood like cedar.

Purebond no Added Formaldehyde Plywood – Purebond Plywood is widely known as the healthier alternative to interior grade plywood.

When folks talk about formaldehyde-free plywood, this is the one they are referring to.

Their adhesive is partially proprietary, but they claim it is “soy-based”. The full Declare label is here but this doesn’t say much about what it will offgas.

I have seen chemically sensitive folks react to this brand of plywood so I would make sure to test it out yourself before using.

Purebond plywood is “interior grade”, it is not structural and it is not made to hold up to high humidity or moisture.

Folks are using this improperly when using it as sheathing and roof decking.

For those less sensitive Purebond is a good choice for furniture and cabinets. You can find it as a component of many preferred kitchen cabinets companies here. You can buy it at Home Depot and Amazon.

Medium Density Fiberboard (MDF)

Which Chemicals does it Offgas?

MDF is often made with urea-formaldehyde which offgasses more than phenol.

Where it’s used:

You will find MDF in cabinets, solid-core and hollow core doors, furniture, and as part of some flooring.

My posts on kitchen cabinets, furniture, doors, and flooring provide alternatives.

MDF is also used in baseboards and other trim which can easily be swapped out for solid wood.

Glues and offgassing:

There are brands of no added formaldehyde MDF that may be used by some specialty furniture makers, but it is not what you will commonly see.

One brand is GP Ultrastock FR, the glues are MDI and another isocyanate. Roseburg also makes a number brands: Arreis, Medex, Medite, Permacore, and Fiberlite.

In most MDF the level of formaldehyde offgassing are higher in MDF than in plywood, even if both are CARB 2 certified – 0.11 ppm in MDF compared to 0.05 ppm for plywood.

MDF made with formaldehyde should be avoided where possible in a healthy home.

Oriented Strand Board (OSB)

Which Chemicals does it Offgas?

Boatbuilder  CC BY-SA 3.0

OSB is usually made using phenol-formaldehyde (PF) and MDI as the adhesive (MDI primarily in OSB though they claim the MDI fully cures into a polyurethane). MDI offgases isocyanates.

Where is it used:

OSB is often used in house sheathing – roof sheathing/decking, exterior sheathing and in floors (subfloors).

Usually, OSB or plywood can use used interchangeably for the same application in a building.

Sensitive folks usually choose plywood over OSB, but some brands of OSB listed below can be very good.

Wood types:

OSB is made from either hardwoods or softwoods. The most commonly used softwoods for manufacturing OSB are pines/firs/spruce. Aspen is the most commonly used hardwood.

In the US look for APA OSB which will not contain UF.

There is no added formaldehyde (“formaldehye-free”) OSB, but they may be harder to source.

Particleboard/Low-Density Fiberboard (LDF)

Which Chemicals does it Offgas?

Source CC BY-SA 3.0

Urea-formaldehyde (UF) (the type that offgasses more and for longer) is usually used as the adhesive in particleboard. You may also see MDI used.

Where is it used:

Particleboard can be used in cabinets and in some inexpensive furniture.

For safer options, see my posts on healthy kitchens and healthy furniture.

High-Density Fiberboard (HDF)

Which Chemicals does it Offgas?

Hardboard/HDF/fiberboards could be made with either phenol-formaldehyde (which offgasses fairly quickly), asphalt or no adhesive, depending on type.

Paraffin wax and a small amount of ammonia are typical. Linseed can be added to some types.

HDF is used in the substrate of many floorings like Marmoleum Click and almost all laminates.

It is also used to made Masonite and other brand hollow core doors (as the skin).

It’s often found as the backing to furniture, like dressers and bookcases.

Pegboard is made from HDF.

Structural Engineered Beams and which Chemicals they Offgas

  • Glulam, PSL, LVL are usually made with phenol-formaldehyde (PF).
  • PF is also used for finger joining stress graded lumber.
  • TGI beams are made with PF and MDI glues.
  • Cross-laminated timber can be made with a variety of different glues: polyurethane, isocyanate (EPI), melamine, or phenolic adhesives. The most common adhesives are formaldehyde-free – polyurethane or EPI. With polyurethane being the most common.
  • LSL is mainly made with the adhesive MDI and I have seen a small percentage of undisclosed binders.
  • i beams are made of steel

To avoid laminated wood beams you will have to consider that decision in the very initial planning and design of your house. See this post on considerations that need to be made early in the build for the chemically sensitive.

Chemical Adhesives by Brand

Brands of Plywood and OSB and which Chemicals they use as Glues

  • Norbond Trubond – PF and MDI
  • Aventech Roof OSB – PF and MDI
  • Avantech Subfloor – PF and MDi (claims to be lower-emitting that typical OSB)
  • Ultrastock MDF – UF
  • Medex and Medite II by Roseburg – No formaldehyde MDF
  • Purebond Plywood – no added formaldehyde, proprietary glue used
  • Roseburg – only lists PF as glue
  • Zip Systems – Phenol formaldehyde and MDI
  • Georgia Pacific DryGaurd (what glue?) claim to be lower-emitting than typical OSB.

Cost comparison of OSB, plywood and Avantech Sheathing.

healthy home build consult

Corinne Segura is a Building Biologist with 6 years of experience helping others create healthy homes.

Buy Me a Coffee at ko-fi.com

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

Additional Sources:

https://www3.epa.gov/ttn/chief/ap42/ch10/final/c10s06-1.pdf

http://wooddesign.dgtlpub.com/2013/2013-03-31/pdf/Technical_Solutions.pdf

Filed Under: Healthy Building Tagged With: Healthy building

Non-Toxic Interior and Exterior Doors: A Guide to Door Types and Materials and the Chemicals they Offgas

August 26, 2019 by Corinne 6 Comments

This post is an overview of interior and exterior door types, what they are made of and the potential offgassing of VOCs of each type. We will look at which types are non-toxic and safe, with zero to little offgassing, and which ones contain toxic substances.

The post will focus on outlining the types of doors you will find at big box stores like Home Depot, specialty stores, and online. We will also cover unusual and creative options (including non-wood options) that will suit the most chemically sensitive or the true purist who wants the healthiest door possible.

This post contains affiliate links. Upon purchase, I earn a small commission at no extra cost to you.

If you need assistance choosing non-toxic materials for a build or reno, please contact me for a one-on-one consultation. 

Solid Wood Doors

This category of doors are real solid wood through and through. Only really old doors might be one solid piece (a slab).

Modern solid doors are made from a number of solid pieces glued together in a frame and panel construction.

You might also find flush (flat) doors that have solid wood pieces inside and a veneer on the outside. When looking at a door that has solid strips glued together on the interior, you may want to know the size of the pieces of wood. Some companies may call this “engineered” if the solid wood pieces are as small as 1 inch each. This also, of course, means more glue used in the door.

Wood glues:

Wood glues tend to be quite non-toxic and low to 0-VOC once dry, but you should get a sample if you have reactions to chemicals. I have seen epoxy used as well as wood glue and exterior wood glue.

When testing an epoxy be sure to test both parts mixed in a real-life situation to see how it comes out.

Also, look and what paints or stains are used. This door type can be used for interior and exterior doors. With exterior doors usually coming with a stronger stain or paint.

Accoya wood:

Accoya wood doors are a good option for exterior glass and wood doors. Accoya is a type of wood process where the wood is treated with acetylation to be naturally rot-resistant without adding toxins.

They also claim better dimensional stability and less shrinking and warping from moisture than untreated wood. Check their websites to find the companies that work with this wood and their distributors. These doors are pricey.

Solid wood doors are one of the most non-toxic types. You can find solid wood doors on Amazon, you may find a limited selection at big box stores, and many more options at specialty door stores and though custom builders.

Simpler Versions of doors made only with real solid wood:

Louvered doors can be used when not much privacy is needed. The ones I have seen are made out of just solid wood.

You can find them in unfinished and finish them yourself if you like.

Here is my list of non-toxic finishes and paints.

You can find these on Amazon and at big box stores.


Solid wood barn door can be found at big box stores like Home Depot as well as on Amazon.

You could also make your own solid wood door in this style out of the wood of your choice which would give you more control of the process and the wood itself.

Add hardware from Amazon.

Hollow Core Doors 

Typical interior doors in new houses and apartments are hollow core. You can easily tell as they do seem to be hollow inside and are light.

The interior frames of these doors are solid wood or, more likely, composite like MDF.

To stabilize the hollow interior there may be a honeycomb interior (cardboard, plastic or hardboard) and there might be some solid wood in a strip down the middle.

The outer veneer surface can be real wood in non painted options, but usually, it is HDF/hardboard.

They usually come primed.

Hollow doors could have MDF or other pressed wood products along the frame.

These are interior doors.

What do Hollow Core Doors Like Masonite Offgas?

MDF (in the framing) is made with formaldehyde, there is a fair amount of glue here.

Hardboard/HDF/fiberboards (the door skin) could be made with either phenol-formaldehyde (which offgasses fairly quickly), asphalt or no adhesive, depending on type. Paraffin wax and or linseed can be added.

Masonite brand door:

Masonite doors are the most common door brand of interior hollow core doors. Many want to know if Masonite doors are non-toxic.

Masonite fiberboard skins are not made with an adhesive and are formaldehyde-free, but they do have other additives that are undisclosed (according to the SDS they sent me).

Masonite brand hollow core doors can be made with solid wood framing (which would make those ones non-toxic), but it looks like most of them have at least some composite framing of MDF (which offgasses formaldehyde).

Therefore it’s possible for this door type to have very little offgassing and to be formaldehyde-free if they don’t have MDF and if made with a fiberboard that does not use an adhesive.

Are hollow core doors safe for the chemically sensitive:

Some folks who are avoiding toxins or are chemically sensitive do choose to use this door type. Some do seal it with an AFM sealer or shellac before installing them to seal in some of the offgassing.

See the post on sealers for more info on sealing in offgassing.

Hollow core doors are easy to find at any hardware store and are inexpensive.

Solid Core Doors

Solid core doors have an engineered or composite wood inside, usually a fiberboard.

The outer skin is usually HDF/hardboard.

The other type of solid door is a solid MDF (or another composite wood product molded into a shape and painted).

These are usually interior doors.

This is my least favorite category of doors for those avoiding toxins or for chemically sensitive persons.

Because the core is a solid MDF (or other lower-density fiberboard) this potentially has the highest offgassing of the door types. MDF is made with formaldehyde, they offgas for quite a while.

You can find solid core doors on Amazon, at hardware stores as well as at specialty door stores.

Glass Doors

Glass barn doors, in clear or frosted

Glass barn doors can be found in clear or frosted and can offer some privacy. The benefit is how little there is to offgas.

Glass and metal are inert. In some instances (or for the most sensitive), you may want to wash factory oils off the metal parts. But if you don’t pick up any chemical odors or reactions there, you may just skip that step. Those that need to go the most extreme, would also want to know what kind of finish in on the metal.

Glass and metal barn door. This style might be easier to find than the all-glass at the big box stores. Both types can be found on Amazon.

Frameless all-glass doors are more commonly seen in office buildings, at least in North America, but they can be seen in very modern houses all over the world.

You may find them at high-end residential companies or you may have to look at office supply companies. Frameless glass doors are all glass (other than the door handle, or the base tracks if it’s a sliding door), and are the safest, purist, least toxic door option.

Mirror closet doors can be safe and non-toxic (but check the backing). You can find these at big box hardware stores.

Solid wood and glass doors. I saw these doors pictured left at a B&B. The doors are framed in real solid wood with glass from a local company in Canada, called Wescon that specializes in doors (both custom and premade).

These are “seconds” so they were a good deal. This is a good example of a local specialty door company. They make solid wood exterior and interior doors, some with veneers. Some do have MDF, but you could avoid that style.

Metal doors

This is a typical metal apartment
door that is fire rated

Metal doors are usually intended to be exterior doors. Steel doors are made of heavy-gauge galvanized steel over a core of rigid foam or spray foam (usually with wood framing inside).

They might be coated with a polymer or vinyl that could look like wood or have face veneers, or they can be just painted.

Apartment doors are typically steel in a simple slab construction pictured (the one pictured is by Jeld Wen and is simple steel with paint).

Flush exterior doors often have a core of solid foam (I have seen polystyrene and polyiso). I have seen polyurethane as well. Some have a honeycomb pattern inside as well as steel reinforced.

What’s inside a steel door is well sealed up by the metal (especially if the edges are welded) and so the offgassing should not affect the occupant.

You just want to look at the finish on the outside to make sure that is low-VOC and safe for you. The standard paint on a simple metal door is a primed paint that is baked on and is low-VOC. A simple painted metal door is preferable from a health standpoint to anything faced with vinyl or other polymer.

Masonite metal doors are for residential use (not commercial and apartments) – they have wood framing (real, laminated or composite), some doors have steel framing inside, polyurethane or EPS foam inside and galvanized steel on the exterior (painted).

I have seen folks find used metal doors at used building supply stores. Many supersensitive folks do use metal door intended for the exterior as interior doors, such as the Masonite brand. You can find these at hardware stores and specialty door stores.

Fiberglass Doors

Fiberglass doors are also exterior doors. They have a core of rigid insulation, or polyurethane spray foam inside, and are clad with a fiberglass skin, they usually have a wood look.

Inside the door may be wood (real and or composite) and plastic to frame it. The fiberglass skin is rather thin, but fiberglass is not typically a tolerable material for those avoiding toxic chemicals due to the offgassing.

Though you may find some brands preferable to others, or you may do well with a used one. I prefer metal doors to fiberglass in almost every situation in terms of toxicity and offgassing.

Vinyl Doors

Patio door, sliding glass doors and other glass door types have framing in vinyl, fiberglass or aluminum. Similar to my assessment in my post on windows, I prefer metal. You still have to check for the coating or paint on the metal.

Hard vinyl can be quite tolerable for some, and some brands of fiberglass can be as well. Folks who are sensitive to chemical offgassing and toxins should check out both types, in different brands, if you cannot find metal framed patio doors.

Vinyl can also be used as a skin over metal doors which would not be a preference for me for healthy doors.

Pocket Doors

Almost any type of door including, flush, panel, louvered, and glazed, can be mounted as a pocket door. Just make sure the hardware is rated to handle the size and weight.

healthy home build consult

Corinne Segura is a Building Biologist with 6 years of experience helping others create healthy homes.

Buy Me a Coffee at ko-fi.com

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

Filed Under: Healthy Building, Healthy Interiors Tagged With: Healthy building, healthy interiors

Are Linseed & Tung Oil Non-Toxic and Safe for the Chemically Sensitive

August 14, 2019 by Corinne 10 Comments

This article is a comparison of linseed and tung oils:

  • Are they safe and non-toxic
  • What types of chemical additives are used in the different oil types what compounds do they naturally offgas
  • When do they cure and stop offgassing VOCs
  • Are linseed and tung offgassing any toxic compounds

I review the following oils:

  • Tried and True polymerized linseed (pure and with a stain)
  • 100% Tung Oil
  • Rubio Monocoat (plain and a blue color)
  • Odies Oil

This post contains affiliate links. Upon purchase, I earn a small commission through affiliate links at no extra cost to you.

The video compliments the post:

Linseed and Tung Oil – Chemicals and Offgassing 

Linseed and Tung Oil are the traditional natural finishing oils for wood – some forms also work well as stone and concrete sealers.

Oils that don’t go Rancid

Both of these oils are called “drying oils” which means they polymerize in the presence of oxygen forming a durable and elastic finish. They do not go rancid like semi-drying or non-drying oils.

Are Linseed and Tung Oil 0-VOC?

While all of these oils, the pure ones and ones with additives, claim 0-VOC (a legal term), they do give off natural VOCs, whether these are enough to be considered toxic depends on you and your tolerance.

Are Linseed and Tung Oil Toxic?

The term “non-toxic” means that the toxins are not at high enough levels to do harm to the average person.

During oxidation (curing) of tung and linseed oils, aldehydes and hydrocarbons are produced. Peroxides, alcohols, ketones and acids may also offgas during oxidation (1).

I could pick up this chemical odor very acutely.

In low concentrations, these compounds are not toxic for most people or for healthy folks.

For those who are comprised, aldehydes especially, can be harmful or cause symptoms. This can be considered toxic to someone who is compromised or chemically sensitive. It certainly does cause me symptoms.

Are Linseed and Tung Oil Safe for the Chemically Sensitive?

If you are wondering if linseed and tung are suitable for you and your sensitives be sure to test both in the 100% pure versions, as well as Rubio Monocoat and see how you do.

For those who like pure natural finishes and who are not bothered by the natural aromatics of plants and oils, both 100% linseed and 100% tung would be great options.

Which one was Less Toxic, Linseed or Tung Oil?

I wasn’t expecting to like Rubio Monocoat, the modified linseed oil, because of the lack of transparency of ingredients, but I explain why it turned out to be my top choice in many ways.

The finishes produce slightly different looks and you should also check the application procedure for the oils you are considering, as well as the upkeep

I’m going to compare tung and linseed (including Rubio Monocoat and Odies Oil) in terms of the chemicals added as well as what compounds they naturally give off when curing.

100% Pure Tung – Chemicals and Offgassing

When choosing a tung oil you are looking for 100% pure tung oil.

Are Tung Oils from the Hardware Store Pure and Safe?

I wouldn’t use the “danish oil” mixes from the hardware store, or anything premixed with a thinner.

I have not seen a pure tung oil at Home Depot or other large hardware store (yet). The Behr tung oil contains petroleum waxes, petroleum distillate solvents and metallic driers.

Pure, Safe Tung Oil Brands

My top brands for pure 100% tung oil are Real Milk Paint, The Hope Company and Heritage. We want to start with something pure that does not have additional chemicals added. I found the Real Milk Paint Tung to be more mild than the brand I initially tested in this post which later changed my view more favorable towards tung.

Can Tung Oil be Used Straight Without a Thinner Additive?

Tung oil can be applied without a thinner to weathered wood, new wood floors as well as some old wood floors and concrete.

Check to see if your application requires a thinner before starting because the thinners are chemical compounds that may not be tolerable or desirable.

What are the Chemical Thinners in Tung Oil and are they Healthy and Safe?

Common thinners for tung oil are citrus solvent, mineral spirits, or odorless mineral spirits.

The thinners can be very hard to tolerate. I describe the citrus solvent as “brutal” – it wipes me out and makes me very sick, it does not dissipate quickly. Just because it’s natural does not mean it is safe.

If I had to pick one I would use odorless mineral spirits which should dissipate (offgas) quickly, in theory.

However, whenever you are applying something yourself things get more tricky. If a non-sensitive person is applying the oil you may opt to use an additive that will dissipate quickly and wear protective gear.

Is Tung Oil Food Safe?

100% tung oil is food safe on butcher block, cutting boards, wooden countertops, concrete countertops, and wooden toys once cured. (To err on the safe side, wait 30 days for it to be cured).

Where can Tung Oil be Used/What Surfaces can it Seal?

Apart from wood, tung oil can be used on raw slate (slabs or tiles). Although it did work well on all the stones I tested it on – slate, dark honed marble, light honed marble and granite. It provides such a thick and durable layer that it is not usually used on indoor stone countertops.

You might use it on stones in the shower or outdoor stones.

The Real Milk company has a lot of knowledge here. I was happiest with their tung oil which seemed to be lower odor. I am very happy to support this small company with sharing the discount code for 10% off: mychemicalfreehouse.

It can be used on concrete countertops as well as concrete floors, and works well in those applications.

You can use it on metal, in fact, cans for food used to be lined in tung oil. A coat on some types of steel helps prevent rust.

How Long Does Tung Oil Take to Cure & Offgas?

The companies say tung oil normally takes 30 days for a full cure.

The time it takes to cure is not the same thing practically or scientifically as the time it takes to finish offgassing.

However, in my results at the end of this post, I compare all the oils at 30 days to see if I can still pick up the offgassing.

Companies claim 95-98% cured within 7-14 days and depending on conditions, it can take up to 90 days for a full cure.

Does Tung Oil Cure/Polymerise Faster than Linseed Oil?

There is a statement on Wikipedia that tung comes to a full cure whereas linseed continues to polymerize for years.

I was not able to confirm that statement about tung after looking through all the scientific literature on tung oil and talking to many companies.

In fact, my results after 30 days does not confirm this (comparison at the end of the post).

Cure Times Did Not Line Up With Offgassing Times

In the literature, I did see lots of reference to the idea that tung oil has a superior ability to polymerize due to its a-elaeostearic acid (77–82%) content.

In theory, this gives it a greater chemical reactivity and excellent ability to polymerize (cure) (2, 3).

However this didn’t line up with the end of the offgassing level/time, my sniff test at 17 and 30 days revealed more offgassing of tung than all of the linseed oils I tested.

Comparing Offgassing of Tung and Linseed Oil

The offgassing odors of tung are a little different from linseed.

In my assessment, tung is not as pungent when in liquid form, but they both offgas similar VOCs while curing.

During oxidation, aldehydes and hydrocarbons offgas. Peroxides, alcohols, ketones and acids may also offgas during curing. (1).

At the end of the experiment, the two had reversed in my assessment: tung was the strongest at 30 days. The end of the post shows the comparison.

How to apply it instructions here.

Linseed Oil – Review of Chemical Additives and Offgassing

Linseed Oil Comes in Three Types

1.  Raw, which is pure, not usually used for wood, as it takes a long time to dry and is often cut with a thinner.

2. “Boiled” which has driers, usually metals like cobalt, or petroleum (which I would want to avoid), this version could be considered toxic if it has toxic metals.

3. Polymerized/stand oil which is pure, food-safe, and faster to dry. This oil does not require a thinner. Polymerised is the type you want to use. I like the brand Tried and True because it’s pure 100% linseed, and because of their total transparency with ingredients and additives.

Odor and VOCs that Offgas from Linseed

The odors of linseed oil (and the citrus solvent) comes from their naturally occurring VOCs (4). For the chemically sensitive, both tung and linseed have odors that are stronger than some other finishes.

The pungent smell of linseed comes mostly from the aldehydes (5).

Do you Need to Add a Thinner to Linseed Oil?

You should see if the pure version works for you first.

I prefer to use linseed oil only on applications that do not require solvents/thinners.

The solvents/thinners should be tested separately, and are not always tolerable (or needed).

How Long Does Linseed Take to Cure?

Linseed will dry within a few days.

But according to the literature, the drying (curing) reaction of linseed oil continues for many years even when the oil film effectively drie in a few days (7).

You can speed up the offgassing odor by increasing temperature and decreasing humidity. Raw linseed might be different in this regard, compared to modified oils with driers.

Comparison of Linseed and Tung Oil Offgassing

Tung oil has milder offgassing compared to polymerized linseed in my assessment at first, but at the end of the 30 days, tung had a stronger odor left.

Rubio Monocoat (modified linseed with driers), was the exception, it was far less pungent than either polymerized linseed or tung.

Surfaces to Seal with Linseed Oil

Linseed Oil is mainly used to seal wood.

It should not be used on marble or granite.

Odies Oil has been used as a concrete sealer which I am quite certain is linseed based, but the ingredients are not disclosed.

(In the video, I discuss why I think Odies Oil is linseed based.)

Here are the instructions for the application of polymerized linseed oil.

Is Linseed Oil Mold-Prone?

Woodworkers having varying opinions on the two oils, each camp preferring one over the other with some noting caution to linseed as being less mold resistant in certain conditions.

Outside in high humidity linseed does not do well. For indoors with regular humidity levels, linseed will work just fine, and I have no trouble recommending it.

Tung oil has the advantage of holding up well to water and mildew outside.

Top Non-Toxic Brands of Linseed Oil

1. Rubio Monocoat Linseed Oil Finish

Rubio Monocoat makes linseed based finishes (natural and modified) that smell like honey or lemony incense.

It contains a wax component (natural and modified) as well.

They claim zero-VOCs but you should test any linseed product before using it.

Chemical Additives in Rubio Monocoat

The accelerator which is a part B drying agent lists hexamethylene diisocyanate as an ingredient (0.5%), but not all ingredients are listed.

Because part A (without the drier) takes a very long time to dry, it sounds like part raw linseed to me (though it does not smell like raw linseed). This means Part B is unknown driers and hexamethylene diisocyanate.

It does contain non-aromatic hydrocarbons, I could not get the company to claim no metallic driers, but they do claim no solvents.

I will always prefer brands that disclose all their ingredients.

Why Rubio Monocoat Turned Out to be My Top Choice

Sensitive folks reporting that they really like this brand is important data, and caused me to seriously consider it.

It turned out to be my top pick based on odors, offgassing level as well as personal tolerance.

I was surprised by how mild it was from start to finish, though I did still pick up a chemical odor at 30 days in the plain color.

I was very impressed with Sapphire which I found cured to my nose at 30 days. Because it’s easy to apply, easy to touch up and seemed to have the least offgassing, much lower than I expected, I have to say it is my top pick. Though with reservations, since we don’t know everything that is in it.

I would like the company to confirm no metals since metals are a major health problem for many of us.

Performance of Rubio Monocoat

This brand offers unique colors in their stains that few other natural option offers (greys and white).

Be sure to sample both Part A and Part B as well as different colors, which for me tested quite differently. I tested plain and sapphire.

It also is easy to touch up which is a major bonus.

Cure Time and Offgassing Time of Rubio Monocoat

Rubio Monocoat (Part A & B mixed) takes one week to cure, they say. You could use just part A which takes 3 weeks to dry.

Although I say in the video it is approaching offgassed at 48 hours, at one week my sense of smell ramped way up (due to a reaction I had to something else), at this point, I could still smell it very noticeably.

So the time that it cures will very much be dependent on you and your level of sensitivity.

2. Tried and True – Polymerised Linseed

Tried and True Java
Polymerised Linseed

Tried and True is my top recommendation for pure linseed with a stain because it is totally pure and because of their full disclosure of ingredients.

No driers are used.

This company can claim that metals are not a component in their pigments other than what comes naturally from the soil.

Performance of Tried and True – Review

I really liked the look of the Java stain (pictured), it went on beautifully even though I did not sand and prep my wood properly.

That’s going to give you a high-quality stain/finish in one. I was really impressed with how the stain looked after my disaster trying to mix my own pigments with hemp oil.

They offer versions with waxes and resins as well, check out the different formulas to see which suits your project.

3. Odies Oil (Universal Finish)

Odies Oil (the Universal Finish) is another oil I tested in the video.

I suspect this to be a linseed based finish. The ingredients are listed as: lubricating oil, drying oil, natural waxes; essential oil.

They claim solvent-free, that it contains UV inhibitors, and it has the warning for spontaneous combustion (which is seen on almost all drying oils).

My Experiment to Guess What is in Odies Oil

I made the following mix which came very close to the odor of Odies: mineral oil, linseed, beeswax, carnauba wax, lemon and orange oil.

I did not get the exact match but it seemed pretty close, therefore, that is my guess on the basics of what is in Odies Oil.

There is still is another essential oil I think, lavender or similar, something flowery.

And there is a different mix of waxes I think, compared to my test. But I got quite close to their mix, according to my nose.

Odor and Offgassing of Odies Oil

This tested quite strong to me at first, with the essential oils being overpowering for me (I’m extremely sensitive to essential oils) in the first 24 hours, but at 48 hours that had faded significantly, and what smelled to me like linseed was then dominant.

Those who are reactive to essential oils might have trouble with this one, but you can see how fast it fades for you.

As always, I’m not a fan of using products that I don’t know the ingredients of, we don’t know if there are toxins in here, but it did cure faster than some of the others.

They claim 2-3 weeks to cure.

4. Other Brands

Fusion tung oil is a similar oil and stain in one but they don’t reveal all the siccatives (driers). This brand does have other products that I am a fan of, but unknown driers is not one of them.

Oils labeled as teak oil or danish oil from hardware stores are usually a mix of oils like linseed or tung, solvents, and possibly resins, UV inhibitors and mildewcides.

I wouldn’t use those, go with one of these pure brands.

My Test Results

My test results at 24 and 48 hours are in the video.

My testing at 17 days 

  • Rubio 1st place 
  • Tried and True Java 2nd place
  • Odies Oil and Tried and True still quite noticeable odor, 3rd place
  • Tung actually the strongest at 17 days, last place (though I like the Milk Paint version better).

My testing at 30 days when they should all be “cured”

  • Rubio Sapphire – this is the only one that seems totally cured to me at 30 days 1st place.
  • Rubio plain – I can pick up the Rubio plain at 30 days though it is very light. My nose is unable to pick up any offgassing from the
  • Odies oil – very slight odor in 3rd place for offgassing levels
  • Tried and True Java in 4th place very slight odor
  • Polymerized linseed – Tried and True plain still offgassing 5th place
  • Tung oil – strongest one. I do not agree that tung oil cures in 30 days, at 30 days I can still pick up the odor of one coat. I kept it at 30C and about 50% humidity. I cannot say it is 100% offgassed. Last place. Later when I tested Milk Paint brand I was much happier with this and would likey choose it over linseed.

Other Natural Oil Options for Sealing Wood

If these two don’t work for you, try hemp oil. I was really happy with pure refined hemp oil. If you want a totally natural purist option, hemp is a good choice. It’s not as strong of an odor as the others.

Other finishing oils reviewed in my main post on finishes are coconut, walnut and rosewood. That post is also a comprehensive overview of water-based 0-VOC and non-toxic finishes for wood as well as stone and masonry.

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Corinne Segura is a Building Biologist with 6 years of experience helping folks create healthy homes.

Buy Me a Coffee at ko-fi.com

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

Sources for this Post

 1. EPA 1991 Impact Of Declaring Soybean Oil Exempt From VOC Regulations On The Coatings Program  

2. Modern Technology of Paints, Varnishes & Lacquers (2nd Edition), NIIR Board February 7, 2007, ASIA PACIFIC BUSINESS PRESS Inc. 

3. Meiorin, C., Aranguren, M. I., & Mosiewicki, M. A. (2015). Polymeric networks based on tung oil: Reaction and modification with green oil monomers. European Polymer Journal, 67, 551–560. 

4. Identification and Quantitation of Volatile Organic Compounds from Oxidation of Linseed Oil
Juita, Bogdan Z. Dlugogorski, Eric M. Kennedy, and John C. Mackie. Industrial & Engineering Chemistry Research 2012 51 (16), 5645-5652  

5, 6, 7 Low temperature oxidation of linseed oil: a review. Juita, Dlugogorski, B.Z., Kennedy, E.M. et al. Fire Sci Rev (2012) 1: 3.  

Filed Under: Healthy Building, Healthy Interiors Tagged With: Healthy building, healthy interiors

Non-Toxic Grout and Thin-Set Mortar

July 15, 2019 by Corinne 44 Comments

Updated Spring 2020

This post contains affiliate links to relevant products that I use and recommend. Upon purchase, I earn a small commission at no extra cost to you.

For individual help on choosing the best products and materials for you and your home, you can schedule a consultation with me here.

Non-Toxic Thin-Set Mortar

Thin-set is the bonding layer that goes down under your tiles. Concrete based thin-sets are the safest type and are also easy to source.

Brands

I used Custom Building Products Standard Thin-Set Mortar which is zero-VOC (and mildewcide-free). It had a light “wet concrete odor” when wet but it is safe once dry.

Unmodified Thin-set (no Additives)

An unmodified concrete based thin-set that is not mixed with acrylic-latex additives.

The unmodified type is recommended for floors and may not be suitable for all applications. Schulter also makes SET, an unmodified thin-set mortar.

These non-toxic thin-sets are more prone to cracking than ones with additives, and you have to check if your application requires polymers.

Modified Thin-set

On walls thinset usually has some acrylic-latex additive. Ceramic tile doesn’t need much acrylic-latex, porcelain tile needs more.

Other Types

Most chemically sensitive folks would want to avoid the toxic epoxy thin-sets and most mastics. Although there are some safe and tolerable tile glues like AFM 3 in 1.

Thin-set mortar is also known as dry set and dry bond.

Non-Toxic Tile Membranes / Underlayments

non toxic no offgassing odourless underlayment
Schluter Kerdi 

Over the first layer of thin-set, I used Schluter DITRA (polyethylene with a fleece backing), an uncoupling membrane that will help prevent cracking when my tiny house moves (it worked well and did not have an odor to me).

Polyethelene is a very safe plastic. In regular-sized houses, you can use this as well to prevent cracking.

If you just need a waterproofing membrane, use Schluter Kerdi (a modified polyethylene (PEVA) core with non-woven polypropylene).

Membranes for the Walls

For a tiled shower, the Kerdi shower system is recommended by architects to create a mold preventative shower.

Be sure to test all parts including Kerdi Fix sealant if you are sensitive to chemicals (though you can use your own thin-set, as long as it’s compatible).

Integrated Membrane Boards

Instead of using the membranes over concrete backer boards (backer boards discussed in this post), you could use Kerdi Boards or Wedi Panels. Test for tolerability before proceeding, they are not odor-free. But they will be behind the thin-set, tiles and grout, which will be safe for most people.

These integrated membrane wallboards help simplify things by replacing concrete backer boards + membrane with just one substrate that is easy to waterproof.

The panels are made of non-toxic 0-VOC polystyrene with a plastic membrane already integrated.

Concrete Based Non-Toxic Grout

Concrete grouts are the safest grouts and are generally non-toxic. You don’t need to go to a green building store here, these grouts can be found at regular building supply stores.

Top Brand

I used Custom Building Products Polyblend grout, the same brand as the thin-set, which like the thin-set is 0-VOC and contains no mildewcides or antimicrobials.

It comes in sanded and unsanded and in different colors. (Unsanded is for marble and certain tiles). You can find this at Home Depot as well as Amazon.

It barely had an odor, though it does have polymers (listed as EVA). Almost everyone does well with this one.

Alternative Brands

Mapai Keracolor (U and S) is another brand that lists the polymer – we know it is EVA.

If those don’t work for you, Hydroment is also recommended for people with sensitivities. However, it has a small amount of latex additive (this usually refers to acrylic) and contains an antimicrobial, which appears to be silver-based.

Laticrete also makes a number of 0-VOC grouts and thin-sets. It’s a matter of finding out which additives work for you and if additives are required for your application.

Many Laticrete products use Microban, which is this case almost certainly refers to Microban’s silver antimicrobials.

Make Your Own Grout

If you need to avoid all additives, you can make your own grout with Portland Cement mixed with sand, lime, and water for a totally chemical-free option. 

Here are the ratios from Craftsman’s Construction Encyclopedia. To mix your own unmodified grout it is a ratio of Portland cement to sand, 1:1 for 1/8th joints, 1:2 for 1/2 inch joints, and 1:3 for over 1/2 inch joints. Adding up to 1/5 lime increases workability.

What are Grout Additives and are They Toxic?

Those who are sensitive to chemicals will probably want a concrete-based grout (like those above) and then see which additives if any can be tolerated.

Since additives are trade secrets and polymer is a word that can mean a variety of chemicals (there are over 10,000 polymers that can be used in cement) you will probably have to test them against your sensitivities.

Common polymers in grout include: latex-based polymers, acrylate copolymers (acrylic eg. PVA), styrene butadiene rubber copolymers (SBR), vinyl acetate-ethylene copolymers (VAE), and ethylene-vinyl acetate (EVA).

They might come mixed in or you might mix them in yourself. Mixing them means you can test the additive against your sensitivities in a more concentrated form, on the other hand, you may not want to test the polymers and the grout until it has cured.

Polymers are added to improve chemical resistance, reduce porosity, improve flexibility, and freeze/thaw stability (source).

You will have to find out when and where you need additives, which will depend on your specific project. I don’t consider most of these polymers to be toxic.

Are Thin-Set and Grout Safe – Why do They Have the Prop 65 Warning?

Sanded grout and thin-sets contain silica (the same substance as glass) which is harmful to breathe in when in dust form; you will see a Prop 65 Warning on every product that contains silica dust.

Use an N95 mask (or better) when mixing it until it is fully wet. This is completely safe when it is no longer in dust form.

There may also be other minerals in there that are only a problem in dust form like aluminum oxide, which can result in a high health rating on the SDS and other warnings. Again, these are safe when it’s mixed wet and when it cures.

Some cement contains fly ash and some don’t. Plain Portland Cement does not have any other harmful additives.

Non-Toxic Thick-Set /Thick-Bed Mortar 

Thick-Bed mortar (also called thick-set or mud set) in its most basic form is simply Portland cement and sand. Custom Building Products makes a mix of 1:3 that is unmodified, it contains no chemical additives like polymers.

This is harder to source than thin-set. 

Alternative to Concrete-Based Grout

For something more waterproof check out QuartzLock; this won’t be tolerable for everyone. It is a urethane-based grout, not cement, and provides more waterproofing.

This grout is significantly higher in offgassing and it should not be necessary in most applications to use this over cement-based grouts.

Your waterproofing needs to be done properly behind the tiles.

There are applications that would call for a waterproof grout.

Epoxy grouts are also waterproof, and may be selected when a clear grout is specified.

Non-Toxic Tile Types

I used concrete tiles from Morocco. For more info on choosing non-toxic tile types, my post on bathrooms goes into the most detail.

Tiles don’t generally have any offgassing. Lead is the biggest concern.

Non-Toxic Grout Sealers

If you are just sealing the grout (and not the tiles) you can use AFM Grout Sealer. It’s 0-VOC and is one of AFM’s most tolerated products. This is a potassium silicate product also known as liquid glass. It’s a breathable densifier (which is what you want).

Custom Building Products grout sealer is another one that many people do well with, less than 1 g/l VOCs. This also looks to be a potassium silicate.

ECOS, a well-liked brand, has a stone sealer that is used on grout. They do not disclose any of the ingredients in this product so it’s not possible to know if it is a breathable densifier or topical coating.

Sodium, potassium, and lithium silicates (aka water glass or liquid glass) is a very safe product that also leaves the grout breathable. It is a densifier so it makes it easier to clean and less likely for dirt grime and mold to get embedded. It’s not intended to be waterproof.

On this topic, I take expert advice from contractor Mike Holmes and architect Cheryl Ciecko. Your waterproofing layer is behind the tile (see the section on Schulter). The grout should be breathable.

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Corinne Segura is a Building Biologist with 6 years of experience helping others create healthy homes.

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Guide to Non-Toxic Glues and Caulks

July 11, 2019 by Corinne 40 Comments

Updated in Spring 2020

Testing wood glues, construction adhesives and silicone caulks was the hardest part of building my house since I did this when I was highly sensitive.

But, you’re going to need glues, caulks and adhesives if you are building so it’s a good idea to start testing them out!

You’re going to need them for repairs and renovations too. I would suggest knowing which ones work for you before that urgent repair is needed.

This post covers low VOC, low odor, non-toxic options that are suitable for the chemically sensitive or health-conscious.

This post contains affiliate links to products I recommend. Upon purchase, I earn a small commission at no extra cost to you.

Non-Toxic Wood Glues

It’s difficult to extrapolate a small jar of dry glue to a house filled with it. (In retrospect I would have tested a much larger dry sample.) I smelled them wet because I got a clearer sign of their relative effects on me.

There is no ideal way to test materials. I test everything wet and dry unless it’s solvent-based.

It is usually a better idea to sniff something dry/cured since there can be a dramatic difference between how tolerable something is wet and when cured.

Testing when it’s cured is the most important test in most cases.

Top Non-Toxic Wood Glue Brands

1. Elmer’s Wood Glue – Not good for me when wet, but many chemically sensitive prefer this brand.

This is a PVA based glue, with a mild acetic odor until it’s cured.

Carried at hardware stores and on Amazon.

2. ECOS Wood Glue – ECOS makes extremely tolerable products, and while I didn’t get a chance to test this one, I would expect it to be good.

The ingredients are acrylic dispersion, thickeners made of cellulose and polymers (plastics), and unlisted dispersing aids.

safe healthy 0 VOC wood glues
Roo Glue was great for me

3. Roo Glue – White glue and wood glue – Not great when wet, but not terrible. It seemed totally benign when dry. The severely sensitive might want to try this brand even though it’s special order.

This is a PVA glue.

Available in the US and it ships to Canada from their website.

4. Titebond – This is a brand that is often recommended for chemically sensitive folks. I had already picked Roo Glue before I got a chance to test it. My sofa was later made with this and it worked out well for me, though I received it after it had cured.

Out of the Titebonds, Titebond III technically has the lowest VOC level of the 3 main types of this brand’s wood glues. It comes in at 5.6 g/l VOC. But that doesn’t mean it will be best for everyone when cured.

These are PVA glues.

I would start here with the testing, since it’s inexpensive and easy to order from Amazon and find in stores.

5. Hide Glue is the most natural glue option for wood. It’s made from animal protein of the collagen from skins, bones, tendons and other tissue.

It is a strong glue with no VOCs, but it is not waterproof.

You can mix it yourself from beads or flakes for the most natural option, or you can buy it ready-made, but those do contain some additives. The Titebond brand lists ammonium thiocyanate.

6. Gorilla Glue – I found this to be difficult when wet, but not terrible. It seemed fine to me when dry.

This is a polyurethane glue that will offgas isocyanates until it’s cured. Isocyanates are potential human carcinogens and known to cause cancer in animals. Like many products, if it comes to you cured it may be perfectly safe.

Easy to find at hardware stores and on Amazon.

Non-Toxic, Low-VOC Caulks and Sealants

Which Caulks are Mildewcide Free?

Note that caulks labeled for bathrooms or as mildew resistant contain a mildewcide. Currently GE I is mildewcide free, GE II contains a mildewcide. Any caulk labeled aquarium safe is free of mildewcides, including DAp Aquarium caulk and others listed below. AFM Safecoat and Chemlink Durasil are also mildewcide free.

Top Non-Toxic Caulking/Sealant Brands

All caulks have a chemical odor when wet. I tested them at 24 hours, 48 hours, one week and two weeks.

I would recommend getting a non-sensitive person to put them in jars and only testing them after they have dried.

1. AFM Safecoat Caulk 

AFM Caulk is one of the top choices along with GE. I used this in my bathroom, you can use this around the shower and sink. It can be used around doors and windows.

My testing: Not the best when wet, not the best at 24 hours, but the best at one week.

Where to use AFM Caulk:

It can be used inside and outside. Around windows, cracks, tub and shower enclosures, backsplash, siding, walls and wood (like sealing molding) and general maintenance. It does not hold up as long in the bathroom as silicone with a mildewcide.

It is polyether resin that does not contain solvents (it’s not acrylic, latex, silicone or polyurethane). It is non-shrinking. 0-VOC once cured.

You have to special order this one from Green Design Center.

Mildewcide: none. Elongation: 35%. Color: white. Paintable: yes

Alternative: ChemLink NovaLink 35 is similar but comes in different colors, if that is needed.

2. GE Silicone 2 Clear Caulk 

This may be a better choice for some applications. This is the next one to test alongside AFM.

My testing: It was not as good at one week as AFM or Ecobond (Ecobond is now out of business). I find that after a couple of weeks it is essentially odor-free (to me).

Testing again in 2020, most sensitive people would not pick up any offgassing at one week (it’s there, but extremely subtle). At two weeks I find this odorless, but when I was at my most extreme I could still pick up something very subtle at two weeks. Thicker amounts take longer.

Offgassing: Most of the caulks (at least all the silicone and polyethers) would be suitable for the chemically sensitive at 2 weeks. Only most extremely sensitive may still pick up some offgassing even at that time.

Where to use GE 100% silicone: Windows, doors, siding, trim, molding, baseboards, vents, around wires/pipes, and more.

We used this on the underbelly of my house and on my windows. It is low-VOC.

Mildewcide: GE 1 is mildewcide-free. Elongation: 50%. Color: Clear. Paintable: No.

Alternative: If GE Silicone doesn’t work for you, you may want to try DAP, their aquarium calk is mildewcide free, Dow Corning 100% Silicone, or Durasil below.

3. ChemLink DuraSil

This is a neutral cure silicone that chemically sensitive folks tend to do well with.

This company makes great products that you can find at the Green Design Center.

I have not tested this one myself but I would expect it to be up there with the most tolerable options.

Mildewcide: No. Elongation: 50%. Color: Clear and White.

4. Silicone Aquarium Caulks

are aquarium caulks safe and non toxic, no offgassing
Aquarium caulks I did not do well with

I read that aquarium caulk is the least toxic because fish are exposed to it and they can’t handle chemicals (especially biocides). But it turns out fish are a little different than people.

I tested two brands, Aquarium Silicone Caulker and one called Marina from a local pet food store, they were much more expensive than brands for home use (for no apparent reason), and they were both the worst of the worst to me.

So bad I would not recommend testing or using these brands. Though one super sensitive person preferred the Aquarium caulk Aqueon to GE I or II and Ecobond.

Marine caulking is not the same as aquarium caulk (it’s for marine applications, not fish tanks). I tested GE Marine Silicone Sealer. It had that same pungent odor though, like vinegar x a million.

It did, however, offgas quite rapidly. After one week it was at the same point as GE 100% Silicone, and at two weeks it was just as good (virtually odorless), but there is a different chemical that is offgassing.

Since folks with sensitives vary so much in their individual triggers, it’s worth checking out multiple brands.

5. Chemlink Novalink35

Chemlink makes an elastomeric caulk for sealing concrete and masonry called NovaLink35.

I haven’t tested this one, but it’s a great brand and many chemically sensitive folks do well with it.

You can find it at Green Design Center and Amazon.

Caulking Materials – What Caulks are Made of?

Polyurethane caulks – Usually contain isocyanate. Might not be as safe. This type smells strongly like typical fresh paint, and takes a while to offgas. They can be made without solvents. If they do contain solvents it would typically be mineral oil, toluene or xylene. It’s not used as widely as the others. I tried Loctite PL S40.

Acrylic Latex caulk – They have the mildewcide octhilinone or carbendazim in them as well as a benzoate plasticizer (which has largely replaced phthalates) and naphtha (source). They are often water based but still could contain mineral spirits, mineral oil, and propylene glycol (source). Painters caulk are usually acrylic latex and are sandable and paintable.

I tried DAP Dynoflex 230 latex caulk and DAP Alex Plus, an acrylic latex with some silicone. At one week they both had more offgassing than the silicones, though they had different chemicals offgassing. At two weeks Alex was still clearly offgassing (at three weeks I could still pick up the odor, at 5 weeks it was very mild), and Dynoflex was close to done at two weeks.

Silicone – While silicone itself is not toxic, the chemicals added to keep caulking in liquid form are. For silicone caulk, look for 100% silicone. There are different types listed below that offgas different chemicals. Once they are cured, you may find them to be essentially the same.

The chemical additives in “100% silicone” are not usually listed. Silicone doesn’t usually have a solvent but some have traces of benzene and toluene (source). Plasticizers are typically added. The biocide, if it has one, is likely to be phenoxarsine oxide, according to Pharos.

Types of silicone caulk and what chemicals they offgas:

1. Typical silicone caulking is acetoxy silicone and it offgasses acetic acid. On the SDS you will see “odor: acetic acid”.

2. The less common type, labeled “neutral cure silicone”, does not give off acetic acid, but instead offgasses alcohols, methyl ethyl ketoxime or acetone. (source)

3. Aquarium caulk is usually acetoxy silicone without mildewcide. It might be labeled aquarium caulk or you can just get GE 1 if you are avoiding mildewcide, which will be less expensive.

4. Paintable silicone caulk is a mix of silicone and acrylic latex.

Top Choices: GE 1 100% silicone doesn’t contain a mildewcide. GE 2* Advanced 100% silicone is “neutral cure”.

Polyether – specialty silicone replacement caulks are often polyether. My top pick is AFM Caulk.

Acoustical Caulk – this non-hardening sealant prevents sound leakage. They are mostly water-based acrylic. They are about 20% ethenylbenzene. In smaller amounts, they typically contain plasticizers, naphtha (as the solvent), ethylene glycol, and formaldehyde.

Solvents common in caulking (of all types) include acetone, methyl ethyl acetone, toluene, xylene, and naphtha (Source).

Non-Toxic Adhesives

Construction adhesives are used for subfloors, to install doors (glue down threshold), to build stairs, exterior brickwork, under countertops, and more.

Non-Toxic, Low VOC Construction Adhesives

1. AFM Almighty Adhesive

Almighty is the best adhesive I have ever tested. I had absolutely no problem and no reaction to smelling it while it was wet.

This was a pleasant surprise after all the other glues and silicones.

It is a highly tolerable very low odor, multipurpose adhesive (make sure it’s right for your application).

It is a polyether adhesive with 1-3% silanes.

I used Almighty to install my shower, on subfloors, and my countertops. I would use this anywhere and everywhere this can be used since it’s the healthiest adhesive I have found.

Insider tip, this is the same formula as Build Secure by Chemlink.

2. Chemlink Wallsecure

Wall Secure is made for bonding drywall, gypsum, landscape blocks, capstones, stone, foam, fiberglass, FRP panels, and ceiling systems.

I haven’t tested this one but this brand makes great low toxin adhesives.

3. Ecotite ET 5500 and 9500

This is another good brand that is well-liked by the chemically sensitive.

Their ET 5500 is an adhesive that works on multiple surfaces: PVC, concrete, glass, aluminum, painted surfaces, wood plywood, marble, metal, and more.

At about one week most would find this odorless. At two weeks it seemed totally offgassed. I was very happy with this one.

The 9500 is used for windows, doors, trim and some kitchen applications. At three weeks it’s still not odorless/offgassed. I’m not as happy with this one as it did not stop offgassing by three weeks.

The bottles say odorless, but the point in time that it is odorless depends on the conditions (curing rate) and how sensitive your sense of smell is.

Right off the bat, the 5500 is significantly milder, and lower odor than conventional adhesives.

The links to the 5500 and 9500 are to a Canadian store, but you can find this product in the US as well.

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Corinne Segura is a Building Biologist Practitioner with 6 years of experience helping folks create healthy homes.

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Filed Under: Healthy Building, Healthy Interiors Tagged With: Healthy building, healthy interiors

Guide to Non-Toxic Drywall: Types and Brands

July 11, 2019 by Corinne 22 Comments

This post contains affiliate links, upon purchase, I earn a small commission at no extra cost to you.

“Mudding Sheetrock” by Forest Service – Northern Region is licensed under CC BY 2.0

Drywall is also called gypsum board, sheetrock, plasterboard, or more generally, wallboard. We are going to look over the types and brands, and which chemicals they contain. Which ones have the least toxic additives, don’t offgas and are the healthiest choices.

For assistance with choosing the best wallboard for your needs, sensitivities, and budget, you can contact me for a one-on-one consult. 

What is Drywall Composed of?

The main ingredient in drywall is gypsum, so let’s start there and look at the health considerations of gypsum. There are two types of gypsum:

Natural Versus Synthetic Gypsum

Natural gypsum is a product mined from the earth. Synthetic gypsum is made from the byproduct of power plants, also called FGD gypsum. They are both technically gypsum.

Unless a product specifically states they use natural mined gypsum, it is exceptionally difficult to track which brands use which type, or if they use a mix.

  • 30% of all drywall in North America is synthetic
  • USG, the largest drywall manufacturer, has 21 drywall plants. 9 of those only use synthetic. 6 use a mix of the two Source
natural gypsum mineral

What Else is Drywall Made up of?

  • Drywall is 70-90% gypsum (synthetic, mined or mixed)
  • 10% paper, on the paper-backed types

Other additives may be included:

  • Cellulose fibers (in monolithic drywall)
  • Fiberglass fibers (fiberglass is in X and C types, and fiberglass backed drywall)
  • Plasticizers
  • Starch
  • Finely ground mica crystal as an accelerant
  • EDTA or other chelating agents
  • Boric acid/borates
  • Wax like paraffin or hydrocarbon, or silanes to hinder water absorption (on the greenboard types)
  • Potassium sulfate
  • Sodium sulfate
  • Vermiculite (in Type C fire resistant drywall)
  • EVA as an adhesive

Source 1, source 2, and SDS sheets

Does Synthetic Drywall Contain Mercury?

Both synthetic and natural gypsum contain low amounts of mercury. It is regulated by the UL standard (ULE 100).

How Much Mercury is in Drywall?

The amount of mercury in synthetic gypsum varies depending on the power plant it came from (source).

It is also a trace metal found in natural mined gypsum. One study found the amounts were 0.92 ng/m2-day for natural gypsum wallboard and 5.9 ng/m2-day for synthetic gypsum wallboard. This resulted in mercury levels in the rooms that were below the background levels normally found indoors and within or below the levels found in outdoor air (source).

Therefore, mercury in drywall has not been a major concern of mine in the past. If you wanted to avoid all gypsum board you would be looking at alternatives like MgO board, covered here, tongue and groove wood (not allowed by all codes due to fire risk), or plaster and lath (wood or metal lath).

Or you could minimize the amount of mercury by going with natural gypsum.

Non-Toxic Drywall – Types & Brands

Natural Gypsum

nationalgypsum.com

National Gypsum makes natural gypsum boards that are VOC-free (the paper backed ones).

Their standard line is the regular Goldbond. LITE may also work well for sensitive folks. More on Light drywall below. The type X is a fire-rated drywall, it contains fiberglass.

You can source this through your contractor’s suppliers. You can get a test sheet at Lowes.

I would rather not have recycled paper-backed drywall. But the other major brands also use recycled paper.

Synthetic Gypsum (and Mixed)

USG, Georgia-Pacific and CertainTeed are the three main drywall producers in North America along with National Gypsum above. These are all easy to source at all building supply stores and through contractors.

The gypsum could be natural, synthetic or mixed, and it’s very difficult to find out which drywall line contains which type of gypsum.

USG SheekRock

usg.com

This is the largest drywall brand and the easiest to source. The SDS sheets claim 0-VOC. They also have GreenGuard Gold certification, which I discuss more below.

The “regular” drywall should contain the least amount of additives (in all the brands). They have the recycled paper, but there should be no mildewcide, fiberglass or other major additives.

USG Sheetrock Ultralight – I have been happy with their Sheetrock Ultralight, I did not pick up any offgassing or moldiness in the paper. Although we don’t know what the blowing agent is, I would feel comfortable using this one in my home due to my own testing of it.

This one is inexpensive and easy to find. You can get it at Home Depot or through your contractor.

USG Firecode X – Research that a very sensitive client revealed that USG was the cleanest gypsum on the West Coast (as it contained more natural gypsum). Though these things change over time, and that same brand could be made in a different factory on the East Coast.

It does not contain a flame retardant, it does contain glass fibers (fiberglass). More on type X below.

Georgia-Pacific

buildgp.com

Georgia-Pacific Gypsum boards are all GreenGuard Gold Certified. Their exact VOC levels are not listed on the SDS.

Like the other brands, they have a “standard” which is what I would recommend as the safest bet. The light can be considered as well.

GP DensArmor Plus is the most popular fiberglass backed drywall. No paper here. They recently made a statement that the Dens line can be treated with biocides.

Certainteed

certainteed.com

CertainTeed Gypsum boards claim 0 VOC (no reportable VOCs), and they have GreenGuard Gold certification.

They have all the same categories of drywall types as the others.

Should you use Paper-Backed or Fiberglass backed?

Many drywall companies use recycled paper which some folks are reluctant to use in their homes. One study showed that paper is already full of mold spores (source). The other concern is that if it gets wet it will mold faster than other materials.

If that is a concern of yours, I would check out the fiberglass backed drywall and see if that is tolerable for you. Fiberglass has some offgassing.

If it isn’t, keep in mind that you should not have moisture or condensation behind your wall if your wall is designed and built right. If you have a big leak you are likely to find that quite quickly. I would not rule out paper-backed drywall, personally.

USG Fiberock Monolithic Drywall

Another type of drywall is called monolithic drywall – no paper and no fiberglass – such as the USG Fiberock line.

It does not have a backing, instead, it contains cellulose fibers dispersed throughout the gypsum. This is a more unusual type, but you should try and test this out for you if you have to rule out the other two types.

Paper backed is the least expensive type, followed by fiberglass backed, and then monolithic.

Behind wet areas, concrete backer board should be used (not drywall), that is discussed in the post on bathrooms.

Types of Drywall with Special Properties – Which Chemicals are Added?

Fire-Rated Drywall

USG SheetRock Firecode C

Type X drywall means it meets requirements for fire codes (that could be required in certain rooms of a house). This type contains glass fibers, is denser, and is 5/8th thick (regular drywall is ½ inch).

It is 10-20% more expensive than regular drywall.

Type C is another type of fire-rated drywall, with a higher rating than type X. It also contains fiberglass and a form of vermiculite. It is more expensive than type X and may be specified for certain areas.

Drywall that Reduces Formaldehyde

Certainteed AirRenew

CertainTeed’s AirRenew (GreenGuard Gold), claims to soak up formaldehyde. However, it contains a biocide that is likely not healthy.

It is a little harder to source than the ones above. In Canada, you can find it at Lowes. Some have reported an odor with this one that might indicate that an additive used to soak up formaldehyde might not work for everyone.

This patent might be related to this brand.

Light Drywall 

USG SheetRock Ultralight

The major drywall companies all have lines that are lighter in weight, and these are very commonly used. We don’t know what is in light drywall that makes it light.

From my testing of it, I did not find that it had chemical offgassing, but we don’t know what the blowing agent is (it could be air or something that dissipates quickly) source.

I did well with USG Sheetrock UltraLite, and I don’t suspect a toxic blowing agent.

Borates are likely to be found in light drywall (source). The SDS will sometimes list borax.

Mold Resistant Drywall 

Both the monolithic (homogenous) drywall and fiberglass backed are slightly less prone to going moldy (or at least to going moldy as quickly) compared to paper backed.

Fiberglass backed may be promoted as more mold-resistant, the brands I have looked at including Dens line does contain mildewcide.

Biocides are commonly used in the paper backed lines, if they are labeled as mold resistant.

USG SheetRock Mold Tough line

Paperbacked brands with mildewcide in them include:

  • Georgia-Pacific’s ToughRock Mold Guard (unclear what it is treated with)
  • Certainteed’s M2Tech (unclear what it is treated with)
  • National Gypsum Goldbond XP (treated with thiabendazol, azoxystrobin and fludioxonil)
  • USG Sheetrock Mold Tough line (treated with sodium pyrithione)

Greenboard is a generic term for green colored drywall like these that have treated paper and are meant for areas with more moisture. It is still paper backed.

GP’s ToughRock Mold-Guard, American Gypsum’s Aquabloc and Sheetrock Mold Tough are greenboard.

Purple drywall by National Gypsum is similar to greenboard. They claim it is treated for mold prevention.

Additional Health Concerns with Drywall

Greenboard

Use the Schulter system over backer board

It is not best practice to use greenboard (including purple) behind tiles that get wet. Best practice here is to use concrete backer boards with the Schluter system discussed in this post on bathrooms. If you want to create a mold preventative shower, Schulter is no question the best system.

Using greenboard behind wet tiles can lead to mold if there is moisture.

They also contain added mildewcides, so I prefer to avoid these types of drywall.

Sulphur Emitting Drywall

The “Chinese Drywall” debacle is the best-known case of a major problem in the drywall industry. For a time (2001-2009) some drywall offgassed sulfur to the point of causing major problems. There have also been lawsuits against American made drywall, but they were dismissed source). I have not seen any issues with sulfur and drywall lately.

In every industry, these kinds of problems do crop up from time to time. Those very sensitive should use their own reactions to guide them. Drywall should never smell like sulfur, and if you react to it that won’t be good for you.

Those who are healthy or less sensitive should go with well-respected companies and do the best you can with the research that we have. Made in America may be better, but is no guarantee that there will not be problems.

The problematic drywall also contained strontium.

Silica Dust 

When drywall is cut and when joint compound is in dust form (straight out of the bag or after sanding), silica, the same substance that glass is made of is, is harmful to breathe in. Silica is perfectly safe when in solid form.

Be sure to take great caution when mixing up drywall mud, when cutting drywall and when sanding the mud.

Use an N95 mask or better when around the dust. I use these masks all the time for many purposes.

The dust is very fine and difficult to remove, I have seen it in builds that are 2 years old. It clings to the wall so you have to clean it very thoroughly.

Make sure the central HVAC is off when drywall and drywall mud work is being done, there should never be drywall/silica dust in your ducts.

Products containing silica dust/quartz will have a Prop 65 warning, keep in mind it’s safe when in solid form.

Should your Drywall be Certified – GreenGuard Gold or UL?

The only benefit to a Greenguard Gold product is it might catch these unusual problems with offgassing that have cropped up – either sulfur or formaldehyde.

More than a decade ago, some drywall did test positive for formaldehyde, in that sense, GreenGuard Gold is the best certification for this case, as it ensures the levels are extremely low, the same as outdoor air. More details on GreenGuard levels in this post on certifications.

Those who do not want to over-research should go with a big brand Greenguard Gold line that does not contain mildewcides. National Gypsum Goldbond if you want natural mined gypsum.

Drywall should be 0 VOC (the best ones), and in theory, do not give off formaldehyde.

UL 100 is somewhat helpful in that it regulates mercury, but I expect all drywall to have very extremely minuscule levels of mercury.

For drywall mud (spackle/joint compound), drywall tape, and mud for textured walls see my dedicated post on this topic.

For assistance with choosing the best wallboard for your needs, sensitivities, and budget, you can contact me for a one-on-one consult. 

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

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Sources:

1) https://www.buildinggreen.com/primer/synthetic-gypsum
2) https://www.thespruce.com/what-is-drywall-made-of-1821482
3) SDS sheets for all the major brands
4)http://www.teledyneleemanlabs.com/resource/Application%20Notes/AN1301%20Determination%20of%20Mercury%20in%20Synthetic%20Gypsum.pdf
5) www.ncbi.nlm.nih.gov/pubmed/19452875
6) https://www.researchgate.net/publication/298054499_Pre-contamination_of_new_gypsum_wallboard_with_potentially_harmful_fungal_species
7) http://www.freepatentsonline.com/y2011/0113961.html
8) https://www.thespruce.com/ultra-light-drywall-1821478
9) https://www.borax.com/BoraxCorp/media/Borax-Main/Resources/Brochures/borates-gypsum-board.pdf?ext=.pdf
10) https://www.propublica.org/article/american-made-drywall-emerges-as-potential-danger

Filed Under: Healthy Building Tagged With: Healthy building

A Guide to Non-Toxic Sealers and Varnishes

June 12, 2019 by Corinne 192 Comments

Updated Winter 2021

This post is my overview post on sealers. I’m starting with oil sealers for wood because these are the only totally pure and natural options. Natural waxes are sometimes used with oil finishes and so those follow.

But what about if you want to add a stain to the wood? Onto looking at both non-toxic water-based wood stains and natural oil stain and finishes in one.

Then an overview of clear 0-VOC water-based wood stains – some of these are durable enough for floors and others are only for furniture or walls.

Cabinet paints are next. A notoriously difficult surface that needs a smooth and durable coating without added toxins or VOCs.

Another way of looking at sealers is not just as a protector against water and stains but to seal in an offending chemical or odor. An overview of those sealers is included.

Next are exterior sealants, a category that is almost always higher in VOCs than their interior counterparts, these are the healthier options.

Lastly, an overview of stone and concrete sealers and where you can use each of the non-toxic brands in this category.

I recommend all of the products here, some products have affiliate programs and some do not. Upon purchase, I earn a small commission through affiliate links at no extra cost to you.

If you need assistance choosing the best paints, sealers, and finishes for your sensitivities and project, please contact me for a one-on-one consultation. 

1. Natural Non-Toxic Wood Sealers

i. Natural Oil Wood Finishes

Rubio Monocoat on floors by @wdflooring
@fourboardwoodworks flooring & installation
@thomashartshelby photography

Linseed, tung, refined hemp, soy, and walnut oil are drying oils.

Drying oils penetrate, harden and preserve wood – providing a long-lasting finish that does not turn rancid. 

Coconut oil if refined can be used on wood and won’t go rancid. But it’s not a drying oil, meaning it won’t polymerize and form a durable coating (source).

I wouldn’t recommend using olive or other (non-drying) oils that can go rancid on wood.

Linseed and Tung Oil

natural non-toxic linseed tried and true

Linseed Oil and Tung Oil are the traditional natural finishing oils for wood.

Although they are natural, legally 0-VOC, and technically non-toxic, they do offgas aldehydes (and other compounds), that can be bothersome for the chemically sensitive.

I review tung and linseed in detail in their own dedicated post. That includes a look at Rubio Monocoat and Odies Oil.

I look at additives including possible metals, chemicals added, as well as which compounds they offgas and when they fully cure.

Linseed and/or tung are often labeled as “teak oil” or “danish oil”, though this is a general term that can mean either it’s pure or mixed with additives, as I go over in the post on these oils.

Hemp Oil Finish

Hemp Oil is my top choice for an all-natural drying oil for wood due to how mild and safe the odor is.

It does have a light aroma, which I would consider pleasant. I would test for your own sensitivities (and allergies) by buying a small amount first.

Hemp oil is the only ingredient in the Milk Paint Company and the Homestead House brands. I used the Milk Paint brand and was happy with it. If you order it directly through their website you can get 10% off with code mychemicalfreehouse.

I used hemp oil on all the interior wood in my chemical-free tiny home – floors, stairs, interior door, and window sills. The ladder to the loft did get grimy, though the dirt did wipe off easily.

It’s not the most durable of the wood finishes compared to some more conventional options but I was very happy with it.

Make sure it’s refined hemp oil (made for a wood finish) as opposed to the edible oil from the grocery store.

This finish is certainly one of the safest and healthiest options for wooden toys, butcher block countertops, and other food-safe surfaces.

Walnut Oil

Walnut Oil another drying oil, is used on surfaces like concrete countertops, raw slate, non-glossy marble and granite, soapstone, sandstone, and onyx.

I tested the Milk Paint walnut oil and the odor is very mild, even lighter than hemp. I was extremely happy with its performance on stones.

I go through sealing various stone types more in the countertop post.

You can buy Milk Paint walnut oil on Amazon or on their website. You can use code mychemicalfreehouse for 10% off on the website.

Rosewood Oil

Another oil to check out is Penofin Verde which is Brazilian rosewood oil mixed with other natural oils.

They use “vegetable ester solvents” and zero VOC pigments.

I would expect a solvent odor and offgassing here.

Oils need to be reapplied to wood every few years or more in high traffic areas.

For information on using natural drying oils on stones (which ones work to protect stone and which ones can discolor them), see my post where I test them all.

ii. Natural Wax Wood Sealers

Beeswax & Carnauba Wax

Wood (but not floors) can then be finished with a beeswax polish for extra durability. Beeswax takes 30 days to fully dry.

I used beeswax on my window sills over the hemp oil to provide a more water-resistant finish and I was really happy with it.

It also works well on counters, cutting boards, and toys.

This Beeswax/Carnauba Polish works well but does have mineral spirits in it. Mineral spirits do evaporate quite quickly and leave the product once cured. I haven’t found odorless mineral spirits to be a very toxic ingredient.

Hemp and beeswax mixed, make a great food-grade finish for cutting boards and other items. I like Fusion brand which is 100% hemp and beeswax with no additives.

Walnut oil with carnauba wax works great as well. I have used this brand on many surfaces.

Wax usually needs to be re-applied every year.

Natural Shellac Resin

Shellac is a resin, and one of my top picks for many different purposes.

Shellac, in the purest version, is just the natural flakes of the resin produced by a beetle, and alcohol.

You can purchase flakes from www.shellac.net or Amazon.

Shellac can be used on many indoor surfaces, including floors, toys, and furniture.

Natural, de-waxed shellac, would be the purest choice for most projects. It does come in a synthetic formula as well, so be sure to check which one it is. Regular (waxed) would be used for some applications.

If you want to buy it ready-made, Zinsser makes one they claim is only shellac and alcohol. I discuss this more in the posts on sealing in toxins since this finish is great at sealing in offgassing and odors.

Oils for Earthen Floor Finishes

If you don’t have ox blood on hand, no problem, you can seal your earthen floor with any of the hardening oils we talked about under wood finishes.

I would use Hemp Oil, though a final coat of linseed and possibly wax, may be needed to get it to hard enough. I did find that to be the case on a project I worked on.

Beeswax can also be used in the final coat for extra protection if desired.

iii. Natural Non-Toxic Wood Stains

natural non toxic hemp oil wood

Natural Oil Wood Stains

Each oil in the section above will tint the wood to some degree, so you should test for the look you want to achieve – you might find that you don’t need a stain at all.

You may need a stain just to lighten it.

If you do want a stain I prefer the oil and stain in one options:

1. Rubio Monocoat

Rubio is a low odor modified linseed with many color options. We don’t know a lot about what’s in it other than (modified) linseed and wax. It’s significantly lower odor than pure linseed. It does have a drier, the Part B. I review it in more detail in this post.

It comes in 40 different colors including lightening shades like greys and whites.

They claim 0-VOC, though the MSDS does indicate some VOCs. Despite the unknowns, I really liked this brand for both low odor and performance.

2. Penefin Verde

This is Brazilian rosewood oil based, with other natural oils. They use natural solvents and it contains a mildewcide. It comes in 18 shades including lightening grey and whites.

They claim no odor, though the SDS indicates mild odor, and extremely low VOCs.

3. Tried and True

Tried and True premixed oil and pigment stains went on beautifully. I tested the Java color on oak.

This is pure polymerized linseed and pigment, nothing else added. This is the most natural option, with no solvents or additives.

It comes in 5 darkening shades.

Legally linseed is 0-VOC, but it does give off natural volatile compounds. I do a deep review of linseed and tung oil in a dedicated post.

4. Osmo

A well-known brand available worldwide. Their stains alone are low odor but they are meant to be used with the top coat of Polyox Oil.

Polyox contains sunflower, soya and thistle oil, with waxes, including paraffin, plus de-aromatized white spirits, siccatives, and polysiloxanes. They declare all of their ingredients.

The Polyox oil had a very noticeable solvent odor for me, the majority of that odor did flash off quickly but the general odor did take more time than I expected to go down. I would not consider this low enough in toxins for me to use.

I did really like the stain colors though. The Wood Wax comes in bright colors (along with the usual wood stain colors and greys and white) which would be fun for art and toys.

The Oil Stain, which is for floors, comes in 10 colors including lightening shades.

They claim very low VOCs.

Water-Based Non-Toxic Wood Stains

The truly non-toxic water-based wood stains are more difficult to apply than the oil-based ones.

1. ECOS Paints stains

ECOS makes the most tolerable finishes in my view. The stains come in 14 different shades (one grey one) and a clear coat of varnish follows.

This was highly tolerable for me when I was at my most sensitive. They also have tinted varnishes.

All of their ingredients are fully declared. These are acrylic based, which is usually more tolerable than polyurethane.

2. AFM Durotone

A recently improved formula from a popular brand for the chemically sensitive.

It comes in 11 colors including one lightening shade.

A topcoat is required, either water-based or oil.

iv. Clear Water-Based Wood Sealers

1. ECOS varnishes, which are acrylic based, are super low toxin. They don’t seem to be as durable as the polyurethane alternatives according to many people I have talked to.

I used ECOS sealer on the wood in my kitchen and I was very happy with it. I have not had problems with water marks, and for me, any trade-off was certainly worth the low toxicity.

I find this to be a very tolerable brand that I was able to apply myself at a time when I could hardly tolerate any coatings.

2. AFM Polyureseal is liked by many. It is a very tolerable formula by a high-quality brand. You can expect this brand to be durable.

Vermont Natural Coatings’ interior floor finish is extremely similar to this one.

3. Another low toxin polyurethane that holds up well and is becoming more popular is Vermeister. Some vendors claim it contains no acetone or ammonia, which are exempt VOCs. The SDS sheet does however list ammonia.

4. Very low odor polyurethane and acrylic also include, BioShield Aqua Resin, Earthpaint Aqualine and Easy Safe 1K, and Vermont Natural Coatings. I compare them all in a dedicated post.

I tested and compared all of the clear non-toxic wood finishes – the full post on all the top brands is here.

5. Danish Soap finish. An unusual non-toxic way to finish floors is a Danish process using soap as the finish. You can either use just soap, or soap and lye. Lye is quite toxic while it’s reacting, and I don’t know how long that takes to dissipate.

When used in the making of soap the lye reacts with other components and in the end you just have a safe soap product.

v. Non-Toxic Kitchen Cabinet Finishes

Clear Finish for Cabinets:

  • AFM Acrylacq is a clear alternative to conventional lacquer. It is acrylic and siloxane. You can get a matte look by using 2 coats of gloss finished with a coat of matte. Or you can use the gloss or satin. This is a durable finish. AFM is my top choice in this category. VOC 93 g/l.
  • AFM Poly BP This is a polyurethane finish (with a little bit of acrylic). This is another durable finish for cabinets. VOC 93 g/l.
  • Vermeister Polyurethane finish that claims 0 VOC. It does contain an exempt VOC though, ammonia (ECOS clear varnish does as well!)
  • EarthPaint Easy Safe 1k or NanoTech Clear.
  • Vermont Natural Coatings PolyWhey All-in-One Stain&Finish, and PolyWhey Floor Finish can both be used on cabinets.

Most of these are also floor finishes, my detailed testing of these brands can be found here.

Natural Oil Finish for Cabinets:

  • Rubio Monocoat oil plus for furniture comes in a lot of cool colors. It is easy to touch up and has been reported to work well on cabinets. If you don’t mind the natural linseed oil and some unknowns with the formula, I really like the quality of this finish.
  • Penefin Verde rosewood/linseed 1g/l VOC.

vi. Sealing in Toxins

Sealing in Fungicides

If you are buying new wood-framed windows, the wood will likely have been treated with fungicides and should be sealed with AFM Safe Seal, AFMTransitional Primer, or Zinsser Shellac.

This version of shellac from Zinsser claims that the only ingredients are shellac and alcohol. That’s one you can find at Home Depot as well as Amazon. You can also mix the flakes yourself with Everclear alcohol.

Sealing in Formaldehyde

AFM Safeseal is used to seal in formaldehyde in engineered wood products.

You can also use shellac which is one of the best sealers to seal in odors and VOCs, including formaldehyde.

I have tested these side by side on formaldehyde offgassing, they both performed very well. Shellac beats Safeseal.

Safeseal is made with acrylic polymers. It works quite well.

Sealing in Wood Odor/Terpenes

Clear Coat Options

Shellac is the best sealer for sealing in the odor of wood. Depending on where the wood is, you may need to go over that with another sealer that can take water better.

That shellac is dewaxed, it’s thinner, but it’s easier to paint or coat over. You can go over dewaxed shellac with AFM Acrylacq.

Acrylacq can also be used on its own. The vendors estimate that it seals in the odor on its own by about 80-90%.

Painted Options

Paint on it’s own also seals in a good amount of wood odor and is usually sufficient for most sensitive folks.

Paints with good sealing properties include AFM Safecoat Paint. Higher gloss options seal in more. This is a better seal than other “green” brands like ECOS, but all acrylic paint seal wood odor to some degree.

Adding their transitional primer will be an even better seal.

The other option is to use shellac followed by paint. I like Bullseye (waxed) shellac followed by Annie Sloan Chalk Paint or Rustoleum Chalked.

For more on this topic, see my posts on Sealing in New Offgassing and Sealing in Fragrance, Smoke and Related chemicals.

You can always contact me for one-on-one help so we can find the best product for your application.

vii. Exterior Wood Sealers

exterior non toxic wood finishes

Natural Oils

To protect exterior wood against the elements, you could use more potent oils than you might used inside – oils like Rubio Monocoat hybrid, and Penofin Verde.

Rubio doesn’t declare all of their ingredients but I was quite happy with it. Penefin has natural solvents and I would expect a fairly strong odor there, though I have not tried it myself.

I like Milk Paint Company tung oil with pine and zinc called Outdoor Defense Oil. It contains no other additives. If you do well with tung and pine oil, this could work for you.

AFM Safecoat makes a Natural Clear Penetrating Oil, a linseed based outdoor sealant. It’s made of flax, linseed, hemp, and soybean oils. They claim it’s free of isoaliphate, cobalt, and lead driers as well as aromatic hydrocarbons, mildewcides/fungicides or preservatives. Mold growth can occur with extreme humidity on exterior surfaces (like with all linseed based finishes).

Synthetic Sealants

Clear sealers include the zero-VOC Cedar-Seal, the same company makes another sealer for other woods.

AFM has a new exterior clear sealer called Polyureseal EXT which is an acrylic/polyurethane.

2. Non-Toxic Tile, Concrete & Stone Sealers

i. Stone, Concrete and Brick Sealers

For a detailed look at concrete floor finishes, see this dedicated post.

1. AFM Mexeseal is a surface coating for masonry/stone. It is for unpolished marble, limestone, granite, sandstone, slate, fireclay (brick, tile, terra cotta, pavers), and concrete. Mostly for honed stones – though it can work on some polished stone (you would have to test it). Good for slate floors, and concrete floors. In sum, use on porous interior tile or masonry surfaces where oil and water repellency are desired. Not for use outside. Not for interior showers. The product is polyurethane and acrylic. Very low VOC.

2. ECOS sealer/stain is for concrete, masonry, brickwork, and plaster. They make a solid color concert sealer and semi-transparent concrete sealer. These are acrylic coatings with a little bit of silicone in there.

3. ECOS clear sealer is acrylic, just like the stains with pigment. You can use it on concrete floors.

4. Lithofin for initial treatment for rough & honed surfaces – natural stone, engineered stone, and tiles: ceramic/porcelain/quarry and to touch up and protect polished travertine and limestone surfaces which have become matte or dull over time.

5. AFM Penetrating Water Stop (zero-VOC) for porous, mineral containing surfaces such as brick, pavers, concrete block, and other cementitious materials, stone, and stucco. I used it on my concrete bathroom tiles and on the clay plaster in my kitchen. The only components listed on the SDS are silicone and lye. This product does not create a film on top of the surface, it is like a densifier.

6. AFM Watershield is a clear, penetrating sealer that repels water, grease, and oils. For use on porous surfaces such as concrete, stucco, brick, and stone. This can be used over American Clay Plaster. This can also be used outdoors on vertical wood surfaces e.g. under eaves that are raw wood or those stained with water-based stains such as AFM Durotone. Not for use on decks or horizontal fence railing. This is an acrylic sealant so it will be at least in part, a surface coating.

7. Milk Paint Soapstone Sealer is walnut oil and beeswax. It works well on soapstone, concrete, raw slate, honed marble, granite, sandstone, and onyx. You can buy this from the Milk Paint store and Amazon. I have used this sealer on many stone surfaces and I have been really happy with it. It’s all-natural and low odor. It needs some time to cure, but all natural oils do. You can get 10% off with the code mychemicalfreehouse.

8. Hemp Oil is also a drying oil, and like walnut oil, it does work on most stone and concrete (as well as wood). It can change the color of some stones, so test it first. It passed my tests, but it can yellow or green just a little, depending on the base color of the stone.

9. Metacreme is a synthetic water-based low odor sealer for natural stones and concrete. I have tested this one on stone countertops and found it quite good. It has a chemical odor that is fairly mild. It works on marble, in wet areas, and goes over the grout as well. This could be used if walnut oil is changing the color of stone too much, though in my tests it did not hold up as well to what I threw at it.

10. Acri-soy is a concrete sealer that can also be used on stone as well. This is an acrylic made from natural sources. This page explains what that means.

11. Tung oil also makes a good finish for concrete and many stones. It can be used on concrete floors as well. It is often preferable to other oils in outdoor conditions. The odor is higher than the other natural oils and even the synthetic sealers (I review the offgassing odors of tung and linseed in a dedicated post). Though some might prefer this oil and not be bothered by the natural odor. Tung oil forms a very durable film.

For a detailed look at my testing of natural sealers on stone surfaces see my dedicated post.

ii. Concrete-Based Grout Sealer

For sealing grout there are a number of good options, I discuss grout sealers options in my post on grout and thinset.

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Corinne Segura is a Building Biologist Practitioner with 6 years of experience helping others create healthy homes.

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Filed Under: Healthy Building, Healthy Interiors Tagged With: Healthy building, healthy decor, healthy interiors

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Hi, I’m Corinne, I am a Certified Building Biologist Practitioner with 6 years of experience helping people create healthy homes.

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