My Chemical-Free House

A Guide to Creating a Healthy Home

Non-Toxic Insulation: A Complete Guide

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There are so many excellent choices for non-toxic, healthy, green insulation, there should be one to fit everyone’s needs.

Look out for Greenwashing

There are many new options that claim to be “green” “soy-based” or are formaldehyde-free – this does not mean that they are VOC-free or safe. Look very closely at what’s in it. Also, flame retardants and mildewcides are not counted as VOCs.

Green Certified?

On top of that, certifications are not that useful: almost every insulation now qualifies as GreenGuard Gold, which for sensitive folks is not enough information.

The post includes the best of green non-toxic insulation and includes a cost comparison as of 2020.

What is the Safest Insulation?

Well, that depends. Technically, the options with no offgassing and no additives are the purest. But the natural odors in the organic options might not agree with everyone. Neither will the cost or availability.

Mineral wool is my top pick for most people, in most cases, because it’s simple in its composition and comes to a complete cure, leaving a 0 VOC product.

The types are outlined below organized by where they are used in the home, and in the order in which I would consider them in.

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.

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

Options Used in Wood Framed Houses

1. Fiberglass Insulation

Fiberglass is the most common insulation used in standard stick-framed houses in Canada and the US. For this reason, I am starting here. It’s not actually my top pick in the batts category.

You can use it between wooden studs of a house, between floor joists and in the attic. It is used in many trailers, but I don’t recommend that.

This option has improved dramatically in recent years, and the following brands are now extremely low in VOCs.

Formaldehyde-Free Fiberglass Brands:

1. Knauf EcoBatt is recommended by many extremely sensitive folks who could not tolerate polystyrene, cotton, or wool. They are formaldehyde-free and their declare label lists all ingredients down to 100 ppm.

2. Owens Corning Ecotouch fiberglass insulation has GreenGuard GreenGuard Gold certification. The binder is formaldehyde-free and “made from widely available plant materials”, according to the company. All ingredients except the pink dye are listed. The patent can be found here.

3. Certainteed Fiberglass insulation is also made with a plant-based binder.

4. Johns Manville Fiberglass insulation is GreenGuard Gold and uses a formaldehyde-free acrylic binder. A patent by the company that is likely related to this product can be found here.

What are BioBinders in Fiberglass Insulation?

We don’t know much about what bio binders actually are, but by looking at this patent you can tell that they look mostly safe. However, it’s hard to zero in on what it is.

There are some preservatives in there, and when they use a biobased binder it looks like they are adding a biocide. (According to patents the acrylic binders might also use biocides, but which type is unknown).

Are there Flame Retardants in Fiberglass?

Fiberglass insulation is made with boron but I don’t see any other flame retardant added, especially in the batts that do not have paper backing, and in the spray in type.

Neither Declare labels nor the companies’ patents suggest flame retardants. Pharos also does not list flame retardants as a component.

Blow-in fiberglass that I have looked at recently contains borates, soda ash, lime, siloxanes/silicates/silane, mineral oil, and an unknown anti-static additive.

Owens Corning unbonded loose-fill and Knauf Jetstream Ultra look similar. A client reported a “strong smell” from JM Climate Pro Fiberglass blow in, but I don’t see the ingredients for that one, so I cannot compare it to the other two.

  • R-Value
    • 3.5 inches is R-11-R-15.
  • Cost USD (2020)
    • Knaff Ecobatt is 0.49/sq ft and you can buy it at Home Depot or through your contractor.

2. Mineral Wool Insulation

Mineral wool is my top choice for batt insulation. It is in widespread use by builders who build green or high-quality homes and is the most obvious alternative to fiberglass. It is also easy to source.

  • The batts can be used between wood studs anywhere in the house.
  • It’s very good at staying in place with compression fitting, so it fits well between framing.
  • It fits and holds up well in ceiling joists.
  • It can be used in an attic if detailed really well and if you don’t do well with any of the blown-in options.
  • It can be used on basements walls.

Non-Toxic Mineral Wool Brands

1. Rockwool (formerly Roxul) is the most common and accessible mineral wool insulation.

They have a newer version called AFB, that does not contain formaldehyde. The binder is an undisclosed polymer (a plastic, likely acrylic), it also contains mineral oil. It’s much harder to source than their standard batts.

The standard Rockwool ComfortBatt does contain phenol-formaldehyde which will cure completely and quite quickly if it’s not already cured by the time it gets to you.

Rockwool ComfortBatt is the type for perimeter exterior walls, Safe N Sound, their soundproofing version is for interior walls, and ComfortBoard is exterior insulation (outside of the sheathing). All three contain the same binders/additives: <3% phenol-formaldehyde, <1% starch, and <0.2% mineral oil Source.

You could try both options (the regular and AFB), but there are few situations in which the regular Rockwool does not work for someone after airing it out for a short time.

2. Thermafiber by Owens Corning is a brand that has a regular phenol-formaldehyde line and a formaldehyde-free line (you will see the letters FF), which usually has to be special ordered through a store. They also have a blown-in option as well.

3. American Rockwool is a brand that is harder to source (in 2020 they stalled production). The company claims no chemical additives or binders, and that would be a bonus for the extremely sensitive. They also have a blown-in option.

Other Info

An easy way to cut through mineral wool is with an electric carving knife.

This insulation has good soundproofing qualities. The Safe n Sound version can be used on interior walls for soundproofing between rooms.

The fibers can cause a contact allergy if you are not using gloves, but the insulation itself is hypoallergenic for most people.

  • R-Value
    • 3.5 inches is R-15.
  • Cost USD (2020) 
    • $0.95/ sq ft for Rockwool (Comfortbatt, 3.5 inch)
  • Where to Buy
    • You can find Rockwool and Thermafiber at hardware stores across the US and Canada, or through your contractor.

3. Wool Batt (and Blow-In) Insulation

Havelock Wool Insulation via www.havelockwool.com

Less common and more expensive, wool batting might be the next insulation type to consider if you want a non-fiberglass option and you have ruled out mineral wool.

It can be used between wood-framed walls and in the attic floor.

Top Brands of Wool Insulation

1. Havelock Wool has no synthetic fibers and no binders. It’s only wool and boric acid. They provide a Declare Label for all of their ingredients. This is the purest of the wool options (and really the most natural insulation all around).

It’s definitely a favorite in the environmentally sensitive community. You can buy it online which makes it the most accessible option.

2. Oregon Shepard adds boric acid, sodium pentaborate dehydrate, and a proprietary component that includes a natural protein, last I checked with them.

3. Black Mountain NatuWool which is 95% wool and 5% polyester binder and is treated with borax.

Blown-in Wool Insulation

The purest option here will be the blow-in wool insulation.

Some extremely sensitive folks have done well with Oregon Shepard blow-in and another extremely sensitive person did well with Havelockย loose-fill. I tested Havelock and found that it did have a noticeableย woolyย smell, though others have barely noticed it.

The natural oils of the wool have an odor that may not work for some sensitive people, although it is not an additive or chemical smell.

While none of them claim organic certification, wool is one of the purest options.

As for borax/boric acid, I’m mostly concerned about inhalation, ingestion, and absorption through touching eyes and mouth. I’m not very concerned about it once it’s behind the wall.

  • R-Value
    • Wool in batts has R-13.7 in 3.5 inches
      Blow in dense-pack R-value: can be 15.3 in 3.5 inches
  • Cost USD (2020)
    • Havelock Loose Fill is $1.97/sq ft
      Havelock Batts is $1.62/sq ft
  • Where to Buy

4. Recycled Cotton Batt

Ultratouch Insulation is what my builder used in my chemical-free tiny home. If you rule out fiberglass and mineral wool, this would be something else to consider.

It used to be made from new denim scraps, but they have moved to recycled denim now. It does contain boric and ammonium sulfate and an olefin binding fiber (similar to rayon).

You have to test for your own sensitivities. I became more sensitive to fabric treatments after I moved into my house (and I had the type made from new scraps).

I would not use this insulation again due to its poor ability to hold itself tight in the walls, the potential for mold if it gets wet, and the slight odor I picked up.

It can be used between wood-framed walls though it does not hold itself up well in ceilings/between floor joists, especially compared to mineral wool. I personally would not use it in a basement.

  • Other Info
    • Wear an N95 mask while cutting and installing as it does get extremely dusty when working with it.
  • R-Value 
    • For the 3.5” thickness, you get an R-Value of 13
  • Cost USD (2020) 
    • $0.79/sq ft
  • Where to Buy
    • This had to be special ordered when I built my house. Now, you can buy it at Lowes and Home Depot.

5. Hemp Insulation

Hemp insulation is the newest alternative insulation in the North American market. It’s been used for much longer in Europe.

I think it is very promising. It’s harder to source and more expensive than some of the other options in this category, but it could be really great for someone who wants something natural and who hasn’t one well with the other options above.

Brands

1. Thermo-Hemp out of Europe was one of the first brands.

2. NatuHemp Semi-Rigid panels are available in the UK and Canada. Canadian NatuHemp, which can be shipped throughout Canada and the US, is made of 88% hemp fiber and 12% polyester fiber, with no chemical binders and no off-gassing (they claim).

3. HempWool is 92% wool and 8% polyester. It’s available through their website and ships within the US (not to Canada).

Companies have been coming and going out of business rapidly in the hemp insulation industry.

Ask them what they add to it, apart from hemp: alternate fibers, binders, flame retardants, and if it’s organic. And always test a sample first!

  • R-Value
    • It is R-13 for 3.5 inches
  • Cost USD (2020)
    • NatuHemp is $1.80/sq ft
      Sunstrand batt is $1/sq ft
  • Where to Buy
    • Contact the companies on where to source it.

Blown-In Insulation

1. Cellulose

Recycled cellulose is an option often slated for those with chemical sensitivity. It is a blown-in insulation made with recycled newspaper that contains a fire repellent like boric acid.

Newspapers are made with “soy-based” inks but they still contain many other chemicals in the inks apart from soy, and there are additional additives in the insulation, usually mineral oil.

Dense packed cellulose is often used in Passive House design, which have great attention to details around moisture management and green healthy materials.

It is used in both walls and attics.

Safe Brands of Cellulose Insulation

1. Greenfiber brand from Lowes and Home Depot is 85% recycled newspaper. It contains boric acid, sodium poly borate, sodium tetraborate pentahydrate, amylopectin, and mineral oil.

2. Ecocell makes batts that are a mix of cellulose and cotton. It also contains PET plastic, very small amounts of boric acid, as well as sodium poly borate, and ammonium sulfate. You can find this insulation without ammonium sulfate – that may be special order. This used to be sold at Home Depot but now it’s not clear where to source it.

3. Weathershield brand by Rona in Canada.

  • R-Value 
    • 13.3 for 3.5 inches
  • Cost USD (2020)
    • $0.32/sq ft

2. AirKrete Cementitious Insulation

https://www.instagram.com/p/B5S7DjoBMSk/

AirKrete is a cementitious blown-in insulation that claims to be VOC-free. It has passed the “sleep next to it test” of many an MCS patient.

The company, however, has declined to participate in the industry-standard VOC test as well as the proper R-value test, so there is some doubt around this product’s claims.

We don’t know what the undisclosed 2% of this product’s ingredients are, but many with severe chemical sensitivities have chosen to go with this option and done well with it.

Because it is a foam, it will get into all the cracks and crevices and therefore give you a higher “real life” R-Value than the batts.

Some people have reported shrinking, crumbling, and trouble drying. Here is the source for the concerns.

Paula Baker-Laport continues to recommend this insulation, so I’m assuming that many are still doing well with it.

It can be used in walls and roofs. (Consult with an architect when designing an unvented roof).

Non-organic options like AirKrete are more likely to be hypoallergenic.

  • R-Value
    • R-13 for 3.5 inches
  • Cost USD
    • Around $2.25/sq ft including installation costs
  • Where to Source
    • You would have to check to see if you have a certified installer in your area before proceeding.

3. Real wool, mineral wool, and fiberglass

These three insulation types can be blown in as well. Fiberglass (pictured) is the most common blown-in insulation, followed by cellulose. Mineral wool and real wool blown-in are less common but are healthier choices.

Brand names in those respective sections. 

Exterior Insulation for Houses 

1. Styrofoam/Rigid Foam

i. Polyisocyanurate “Polyiso” Foam Board Insulation

Polyiso is one of the insulation types that is used on the exterior side of sheathing.

Typical current blowing agents for polyiso are CO2 and pentane. There is some “thermal drift”, meaning the blowing agents offgas over time. The offgassing is extremely minimal.

This is going to become a very common exterior insulation as building codes move to require exterior insulation.

It can be used in trailers and metal structures as well.

Flame retardants are a bigger concern than trace pentane. The most common flame retardant is TCPP. It’s best to look for brands that use a phosphate-based FR instead of TCPP, as it’s safer.

Though the foil does block the FR, the edges are unsealed and it will never be perfect.

Healthy Brands of Polyiso Foam Insulation

1. Johns Manville Foil Faced Polyiso has been the most popular brand among those who are sensitive, but they have discontinued Energy 3E, which was the one made without TCPP (it used organo-phosphorus FR instead).

2. GAF polyiso EnergyGuard-NH uses a halogen-free flame retardant (which is phosphate-based, like Energy 3E was). “Unlike TCPP, the flame retardant becomes part of the polymer backbone of the insulationโ€”so there is no free flame retardant that can leach out, according to GAFโ€™s director of sustainability Martin Grohman. TCPP, by contrast, is not chemically bonded to the polyiso polymer, so it can more readily escape.” Source

3. ZIP System R-Sheathing is the Huber Zip OSB sheathing, polyiso and weather-resistant barrier all in one. Though you can use the above two brands as exterior insulation on the outside of the plywood or OSB, “ZIP-R”, as this type is normally called, integrates it into the sheathing, on the interior side.

  • R-Value 
    • Technically it’s R-6/ inch but it’s really about R-5.6/inch over its lifespan because it loses R-Value over time. It also loses R-value the colder it gets.
  • Cost by R-Value (R6)
    • R-6 is $0.60 / sq ft

ii. Extruded Polystyrene (XPS)

XPS (extruded polystyrene) is another common exterior insulation outbound of the sheathing. It is also used on exterior concrete basement walls, underneath the slab, and in trailers.

XPS, like polyiso, has some “thermal drift” i.e. some very slow offgassing of the blowing agents over time.

“Over a long period of time (50 to 75 years), the blowing agent slowly diffuses through the thickness of the foam” (source).

Typical blowing agents for XPS are CFC-12, HCFC-142b, and HFC-134a, but they change their formulas over time. HFC-134a was eliminated from extruded polystyrene on January 1, 2021.

XPS insulation was treated with the flame retardant hexabromocyclododecane (HBCD) until recently.

The two main brands, Dow Styrofoam (Lowes) and Owens Corning Foamular (Home Depot) no longer contain HBCD.

Most are now using a butadiene styrene brominated copolymer as the flame retardant (Source). DOW lists a brominated flame retardant (FR122P) in some of their XPS.

How Concerning are These Flame Retardants in Rigid Foam?

Flame retardants are sometimes considered non-volatile and sometimes semi-volatile. They leach out in dust form as opposed to gas. If they become dust borne in the house, the main route of exposure is hand to mouth, though you can also inhale them.

My post on Flame Retardants goes into more detail.

  • R-Value
    • R-5/inch
  • Cost by R-Value
    • R-5 is 0.60/ sq ft

2. Mineral Wool Board 

The other common and easy to source exterior insulation used in the US and Canada is Rockwool in board form.

The Rockwool Comfortboards will be used more and more as many codes across the US shift to requiring exterior insulation.

Foam and Rockwool will be the two main exterior insulation types to consider since they will be familiar to builders and easy to source.

The boards can also be used on interior basement walls. They are also being used under the slab, as the only alternative to foam insulation there.

  • R-Value 
    • R-4/inch
  • Cost by R-Value (R6)
    • R-6 is $1. 24 sq ft

3. Cork

Thermacork insulation, unlike cork flooring, does not contain adhesives. It is held together by compressing it with heat which releases a natural binder in the cork.

The cork does give off a smoky smell that dissipates with time, as well as the natural odor of cork.

This is a newer product in North America and is more expensive than the more conventional options.

If you can afford it, it is my top pick for non-toxic exterior insulation due to a lack of additives and flame retardants.

It can be used as exterior insulation or even the facade of a house which serves the purpose of siding, insulation, and noise reduction.

See this post as an example or cork used as the facade.

  • R-Value
    • R-4/inch
  • Cost by R-Value (R8)
    • R-8 (doesn’t come in R-6) it’s $4.93/sq ft for the insulation type (rougher than the facade)
      R-8 in the facade grade, which covers your exterior insulation and your siding in one, is 10.77/sq ft
  • Where to Buy
    • You can buy this through green building supply stores.

4. Wood Fiberboard Insulation

Wood fiberboard is often used in High Performance/Passive House designs as exterior insulation. It can be used closer to the interior as well.

One popular brand in North America is Gutex. It is 95% wood (spruce/fir, post-industrial, recycled and new wood), 4% polyurethane, and about 1% paraffin. The total VOC level is 187 ฮผg/m3.

  • R-Value
    • R-3.7/inch
  • Cost
    • R 5.8 is $1.81/sq ft
  • Where to Source
    • You can buy this through 475.

Insulation Typically Used in Trailers, RVs, and Vans

1. Rigid Foam

If you prefer to watch a video on the three rigid foams I made this video to explain the toxins in them.

EPS (Expanded Polystyrene aka Styrofoam)

EPS (expanded polystyrene) is often used in trailers and can be referred to as “block foam” by the companies.

It can also be used as exterior insulation, insulation over concrete basement walls on the interior, and under the slab. Though you are far more likely to see the XPS type of styrofoam under a slab.

Blowing Agents

EPS usually is made with pentane as a blowing agent, the final product has trace amounts of pentane which dissipates rather quickly and completely. Some butane can also be used as a blowing agent.

Sometimes the only blowing agent is carbon dioxide.

0-VOC

EPS, despite the name (polystyrene), does not offgas styrene under normal conditions.

It is considered 0-VOC (pentane and styrene are not exempt from the VOC testing).

What about Styrene?

The concerns over polystyrene (Styrofoam) and styrene comes from the following a) chemicals released during the manufacturing of the product b) the product is very toxic if you burn it and c) the styrene can leach if you drink beverages especially hot or acidic beverages out of Styrofoam cups.

In the form of insulation, I would consider this product to be non-toxic, 0 VOC, odorless, and stable, with the only risk being the flame retardants.

This is a very old product with a long track record. Here are a couple of links to back up the claims.

Flame Retardants

EPS used to be treated with hexabromocyclododecane (HBCD), but luckily it no longer is. Polymeric FR (a copolymer of polystyrene and brominated polybutadiene) is now the most common FR.

The foil faces of these insulations block the flame retardants. However, the foil and plastic-backed versions can have some offgassing odor. Some EPS is not backed with anything.

EPS used in packaging and cups does not contain a flame retardant and people have sometimes been able to source this type of foam for small structures.

If using EPS in a living space I would recommend borate treated foams to prevent ants that love this insulation.

R-14 for 3.4 inches EPS.

2. Reflectix and Prodex Insulation

Reflectix is a bubble foil made of aluminum over polyethylene bubble wrap. It is flexible, very thin, and claims to have a very high R-value. The thicker version claims R-21 (which is higher than 5 inches of wool).

These claims are disputed by Green Building Advisor and the Government of Canada. The former states that the 3/8th-inch foil has an R-value of only 1 (the same as a single pane of glass).

This would hardly be useful anywhere unless it is in a curved trailer or other RV or vehicle where all other options have been ruled out. Sometimes it’s just used to insulate windows, which can be a great help.

Prodex is another similar material – foil and polyethylene-based – that also has a disputed R-value.

Many similar brands can be found easily on Amazon or Home Depot.

3. Aerogel Insulation

Aerogel is a fairly new product – unusual, extremely expensive, and harder to source.

The term itself can refer to a variety of materials from the original silica translucent product to polymer-based products that may include the addition of fibers.

The original Aerogel insulation was developed by NASA.

Aspen Aerogel collaborated with NASA to make their polymer enhanced aerogel combined with fibers.

Some companies are selling insulation online that they claim is Aerogel. I would look closely at what’s really in it. Look for proper studies on the R-Value of it.

They claim an extremely high R-value of R-10 to R-30 per inch.

They may be ideal for small, round, and difficult to insulate places.

4. Thinsulate Insulation

3M Thinsulate (SM600) is insulation used in vans, other vehicles, and RVs.

It is made of polyethylene terephthalate (a type of polyester) and polypropylene fibers which will be tolerable for most people. The backing is polypropylene.

One percent or less of the additives are proprietary and therefore unlisted. The health rating is 0 which is good.

What I don’t love about using this product in vehicles is that the insulation itself is vapor permeable and it is attached to the walls with 3M 90 Spray (GreenGuard certified, not GreenGuard Gold, not reported to be very tolerable by many chemically sensitive).

You may find this insulation tolerable and it may be a good product for a tiny house or structure. You can buy it on Amazon and Ebay.

R-value

5.2 for the 1.65 inch

NB I have seen similar but more unusual insulation made from polyethylene and polyester for homes in batts. (It is more popular in some countries outside of North America.) It may be tolerable depending on what is added to it.

5. Vacuum Insulation Panels 

Vacuum Insulation Panels have the highest insulation value of any of the insulation materials.

These Panasonic panels have an R-Value of R-60 per inch. They were used in the latest Leaf House design (tiny house). This could allow you to build a tiny house for almost any climate. Though this introduces a tricky vapor barrier which needs to be carefully thought out.

The foil vacuum pack will block any VOCs from migrating through, but your moisture management system would have to be planned carefully here.

These won’t work in most houses. You might consider them in some trailers or metal framed homes.

They are very pricey and harder to source than almost all of the others.

6. Non-Toxic Spray Foam Insulation

Spray foam that is used to fill cavities of walls is two-part polyurethane. Some of it may have soy added, but it’s still mostly polyurethane foam.

This insulation has to be mixed perfectly, under the right conditions (there are many), and applied correctly. When looking for a good spray foam you are looking for an excellent installer (the best one you can find) and not a specific brand.

The companies have claimed that it is 0-VOC, or close to that once cured, but many individual tests and many individual noses of those sensitive have shown otherwise.

I know moderately sensitive folks who have looked at many houses with spray foam and been able to pick up the odor for two years.

And that’s when it’s done right. When it’s done wrong it’s a massive disaster that can end in a lawsuit against the company, plus an expensive imperfect removal of all the foam.

If you are extremely sensitive you would lose the whole house if this goes wrong, as the VOCs will soak up into other materials. This has happened to two of my clients.

One part polyurethane, which is the canned stuff discussed below, is much easier to tolerate, it’s used in small quantities, and it doesn’t have the same challenges and risks as the two-part foam.

Insulating Around Windows and Doors – Non-Toxic Options

Spray foam is often used around windows and doors. HandiFoam is GreenGuard Gold and will be tolerable for many folks after curing. In Canada the best source is Organic Lifestyle.

I find this spray foam to be odorless once cured.

Other brands like Great Stuff, which you can find anywhere, seem very similar to me, if not the same.

Great Stuff does contain a flame retardant in some of its lines and Handi-Foam has declined to answer whether it contains a flame retardant or not.

Instead of using spray foam around windows and doors you can fill in the gaps with Backer Rod and seal with non-toxic caulk if needed.

I have a post on caulking if you need to test multiple brands.

healthy home build consult

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

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Reader Interactions

Comments

  2. Tracy says

    Whar about ceramic board or ceramic paper insulation for a skoolie? It is usually used around engine bays to prevent heat transfer, but what about using all over? Is it considered toxic?

    Reply

  3. Tina T. says

    Hi Corinne,
    We are planning our new home and are debating which construction to choose – ICF or concrete block filled with concrete plus insulation on the outside. This will be for the whole house (basement and one floor).
    We are not very sensitive but we are concerned about toxins. I’m wondering if the toxins from the EPS on the ICF forms will leak through drywall over time. How much of a seal is the actual gypsum in the drywall? And what about holes for pictures, cracks etc..
    We are in KY and the summers get pretty humid, so mold is a concern, too.
    So many questions…
    Thank you for making this world a healthier place.

    Reply

  4. Jenny says

    Have you ever looked into the insulation โ€œGuardianโ€œ by Knauf? It is available in store at Home Depot. They do not have the Ecobatt in store. Just wondering if it is a safer option?
    (I would add a product label, but I donโ€™t see an option to insert a picture)

    Reply

  5. Rain Balen says

    Thank you for this useful and comprehensive breakdown of a vast spectrum of insulating building materials, their cost, function, and properties, but I thought it a little strange to find mineral wool and fiberglass in this list as they are known irritants, and their factories keep having issues with mesothelioma lawsuits.

    Hemp wool can, and will, get cheaper as unnecessary regulations are removed and we can begin manufacturing it in the USA, without the need for toxic melting of slag and rock. My company https://www.dopepanels.com , is making acoustic panels with hemp wool insulation wrapped with hemp canvas. I can personally confirm hemp wool’s dopeness.

    Why no mention of hempcrete? Hempcrete is truly non toxic, and 100%DOPE!

    Reply

  6. Yvonne Espinoza says

    Corinne, Iโ€™m not understanding the Rockwool option.
    There are advantages, but at what cost? Or at the very least, possibly not as bad as asbestos?
    Here is one article I found, but there are many that refer specifically to the tests done on Rockwool, and the actual product being sold. The production facilities are also of local concern to residents in the U.S.

    https://www.theparliamentmagazine.eu/news/article/eu-urged-to-act-on-the-possible-health-risks-of-mineral-wool

    Reply

  7. Dan says

    We currently have R -30 fiberglass insulation in connecticut. we are looking to help keep the home warmer by bringing that up to r-49 and the company has recommended blowing in Class 1/A Cellulose directly on top of the existing insulation to R-49 via GreenFiber. It is very confusing. I have seen some sites that suggest staying away from cellulose due to the boric acid and suggest fiberglass. Your article appears to say that GreenFiber is safe and that the boric acide isnt as worrisome for this particular product. could you expand on that please?

    Reply

    • Corinne says

      I am concerned with it used in household products. But the routes of exposure are inhalation, ingestion and absorption (through hand to mouth or eyes etc). I don’t consider it toxic once it’s behind a wall. Though if you are not air sealing the wall with a vapour retarder or in another way it could come through in small amounts.

      Reply

  8. Shane says

    Ok Corinne..here is a tough question! I am currently renovating my home in Ireland. We have opted for grey EPS underfloor and in the flat roof section of the house. From reading your post, I was happy to growth EPS. I was concerned about the FR but I knew it was not an issue being below floor level and above ceiling level. WE also got external wall insulation which also used grey EPS. An unexpected problem has occurred. Through the cutting of these boards, there are EPS beads EVERYWHERE. I feel like we will be finding polystyrene beads in our garden for decades. Also, the house is FULL of them. Hopefully when the house is finished, they can all be eliminated. However, I am still quite concerned. I don’t want it all in the grass where my children play. I don’t want any traces of it left inside our house, I have heard that EPS only contains 0.5-0.7% FR. Is it present in the beads (easy to see) or is it coming off the beads (hard/impossible to see and very hard to eliminate from house prior to one in). I simply cannot describe to you the lengths I have gone to in building a chemical free house. But this issue concerns me…I hope to hear from you soon. Thanks so much Corinne.

    Shane

    Ireland

    Reply

    • Corinne says

      it has to be cut further from the house and with an attempt for some containment like tarps on the ground as it certainly does become a big mess.

      Reply

  9. Jo says

    What is the safest (for hypersensitive human & potential fire) & most energy efficient insulation to use when building a sauna in MN? Keeping the heat in & being able to handle temps up to 200ยฐ & safe from flammability are critical.

    Reply

    • Corinne says

      I would consult with an architect for that one, mainly because of the need to control moisture. Unless it’s just a dry infared sauna. It also depends on your climate and the wall system you have or are going to use.

      Reply

  10. Reuben says

    I was reading this article today and found it quite helpful. I also found the spray foam brand “Tiger Foam” that claims “DOES NOT contain CFCs, VOCs, Formaldehyde or PENTA-BDEs”. Has anyone heard of them, used the product and can you confirm that it is odorless after curing?

    Reply

  11. Irene Zeppieri says

    I am confused. The beginning of your post says that Green-guard Gold certification is not enough. I have found two spray-foam products that meet Greenguard Gold certification. They are using the new HFC technology so are good for the environment and should have low VOC emissions to meet the above certification. Should I be concerned about other chemicals/emissions from these products. In parts of my new home I have no choice but to spray foam……

    Reply

    • Corinne says

      It depends how sensitive to offgassing you are, how thick the spray foam application is, and how perfectly they mix and apply it.

      Reply

  12. Stefanie says

    Aloha from East Hawaii,

    a big mahalo for all the information posted in your website!
    Since East Hawaii climate is different from mainland climate – lots of rain, humidity, saltwater spray from ocean, sun, mold issues …- and I am a vegan (no wool) what would you consider to be the perfect insulation for my tiny home? It also needs to stay affordable and be available here.
    I am organic raw vegan and super health conscious,

    Mahalo nui loa, Stefanie

    Reply

    • Corinne says

      I don’t think there is a perfect insulation for everyone. It depends on how your house is designed to handle moisture, how it’s designed to be able to breathe. If your design calls for batts Rockwool is by go to insulation before going up to more expensive and hard to source types.

      Reply

      • Ronald says

        How is rockwool ‘green’? Requires lots of energy to melt slag and almost all mineral wool batts have formaldehyde binders (unlike fiberglass insulation which got rid of formaldehyde binders decades ago).

        You are a misinformed and should take more care to present accurate facts.

        Reply

        • Corinne says

          I have explained the use of formaldehyde in mineral wool. While the companies claim it’s already cured by the time it gets to you I can pick up a slight offgassing when the bags are new that does cure really fast. I specify this insulation over fiberglass for many reasons, it’s usually a better choice for the chemically and mold sensitive. Though folks can test out both options for themselves.

          Reply

        • Clayton says

          Ronald, this is not a Green forum – it is one for chemical sensitive people.
          Nevertheless, the simple fact that rockwool takes energy to produce doesn’t make it un-green. EVERY form of insulation takes energy to produce, the real questions are (1) what is the ratio of energy consumed to energy saved, and (2) are there other non-production energy aspects that should be considered.
          Rockwool saves over 100X the production energy in a typical lifetime (actually nearly 130X per one manufacturer, but we’ll take that with a grain of salt). It also is hydrophobic, so it is less likely to harbor mold than other options and it also holds its shape, unlike fiberglass batts and many types of green blown-in insulation (cellulose, etc.) that hold condensation and compress over time, which means its insulating value holds up better than other choices over the long term, saving more – wait for it… Energy!
          It has essentially no chemical emissions in use which is critical to chemical- and smell-sensitive individuals. Which, BTW, this forum is about. And what would be the total life cycle energy efficiency if you have to rip out your walls to replace the insulation due to mold, chemical irritation, or both?
          I might almost believe you were a market competitor of rockwool with your narrowly based criticism, but more likely you’re just an ill-informed greenie thinking you’re saving all those lesser intellects out there.
          In fact, it seems like it’s really you who are misinformed and should take more care to present accurate facts.

          Reply

  14. Celina Burns says

    I am totally gutting a single wide trailer for my son who is supersensitive. Where and what kind do I put a vapor barrier. Do I need interior and exterior insulation and what would be the best kind? Do I use a different kind of insulation in the walls that separate rooms. Would I use something different in the bathroom? What insulation should I use in the floors and ceiling.? He is very sensitive to formaldehyde. Please let me know your thoughts on this project. Thanks!.

    Reply

    • Corinne says

      Hi most of this depends on the design of the house – they type of roof and how it is vented or not vented. Give special consideration to the floor of a raised up mobile home as that creates new and different issues compared to homes on a foundation. When you gut is you will see where the problem areas are. The vapour barrier (or usually lack of) also needs to be determined by the wall system and the climate. Most mold preventative builders prefer to design a system that does not use a vapour barrier, in most climates.

      Reply

  15. Todd says

    Is there any form of spray insulation (foam like) that I could use in a crawl space that doesnโ€™t release toxic off gasses?

    The structure is a new construction cottage With poured foundation walls (about 44โ€ from the poured slab to the in derided of floor joists)

    Looking for way to insulate and provide a safe environment for our 5 young children.

    I have been recommended spray foam but I read so much on its off gas issues.

    Any help?

    Reply

    • Corinne says

      Spray foam is sometimes needed but I would not insulate the ceiling of the crawl if that’s what you mean, I would condition the crawl.

      Reply

  16. Unknown says

    I'm a big knauff fan. Reflextic is awesome too. I know the R value is questioned on reflextic but that stuff is GREAT, espcially in the southern states. Under metal roofs and behind crawl space skirting. Waterproof, pack rats don't like it much, and it keeps outside temps, outside and inside temps, inside.

    Reply

    • Jo says

      What is the safest (for hypersensitive human & potential fire) & most energy efficient insulation to use when building a sauna in MN. Keeping the heat in & being able to handle temps up to 200ยฐ & safe from flammability are critical.

      Reply

  18. Unknown says

    Cork factory workers found to be sick from the dust of cork in factories: Respiratory disease in cork workers (`suberosis'). I am not sure if this would affect us after they are made into unsulation panels. Anyone know anything about it?

    Reply

    • Corinne says

      Many products are dangerous in dust form including all wood. And cork is a type of wood bark. Concrete is harmful and dust form glass is harmful and dust form the list goes on. That doesn't mean it's harmful when it is solid.

      Reply

  21. Stacy Hancock says

    I'm currently trying to research what best insulation to use for a school bus conversion. We were planning on rockwool, and then I came across the video where the gentleman mentioned it being made of slag. I don't think slag is safe. Probably doubly so in a moving vehicle where friction might cause dust some how to be released into our living area. I only recently learned about slag due to an issue with some local towns trying to save money and putting that on the roads instead of gravel.

    Reply

    • Corinne says

      It seems to me similar to Concrete and other products where it is hazardous in dust form to breathe that in. This one has an extra component or it seems like it could be hazardous to also handle it with bare hands. It's not something I would use in a bus though.

      Reply

    • Corinne says

      You would need to know which kind of system is needed first, to know if you need batts or foam. Blown in cellulose is often used in the attic as well but first you might need some technical advice there.

      Reply

  23. Crystal clear says

    In search of an insulation that does not off gas and is affordable, I tested different batts by putting them on my wood stove, Rudolph smelt like melting crayons and some form of chemical stuff, but Owens Corning fibreglass with plant based binders passed, it smells like a baking cake. Iโ€™m a super sensitive individual and no off gassing of this stuff, however I have done one wall in my tiny house with 6 ml poly and now I can not enter it without a gas mask…..what can I use as a vapor barrier, what can one use to replace accoustcal sealants….

    Reply

    • Corinne says

      Hi, is it the insulation that is bothering you that you are trying to block? A sample may be offgassed while a new package will not be. Roxul offgasses quickly which is why it's one of my top choices. It's unusual to put an interior vapour barrier like poly. If you ever us AC you would not be able to have an interior barrier in most systems.

      Reply

  24. Winged Lady says

    I called Johns Manville and asked for samples. I am ok with the foil faced board, but they also sent a few pieces of the insulation for the ceiling. It is thicker and is cardboard faced on both sides of the foam. I don't do well with cardboard odors, and this one does have the cardboard odor. So, what to use under the ceiling drywall?

    Reply

    • Corinne says

      Depends on the type of house and the moisture management system. Which insulation are you referring to with paper backing? Has that been recommended by a building science expert for your house?

      Reply

    • Winged Lady says

      No. I'm still trying to figure out which kind of building to build. We are leaning toward Structall panels construction, and that would eliminate the need for the Johns Manville. But I have concerns about EMFs and RF's being trapped in a solid metal building. So, then considered steel frame, and that would need to be insulated. Trying to figure what would be good to use in our very humid sub-tropical environment. Thank you!

      Reply

  25. Unknown says

    I happened upon your site searching for a way to winterize my windows on a budget and without the offgassing. I am sensitive to petroleum based odors. But I am entertaining the idea of using large sized bubblewrap but see HDPE is not considered a zero voc plastic. Could cover window and patiodoor with another clear product after the bubblewrap to create a barrier, but what I wonder? Any ideas would be much appreciated.

    Reply

    • Corinne says

      It would be very unusual to react to the plastic in bubble wrap insulation. It has foil on either side. If you buy it from a big box hardware store it likely picked up other chemical odours there. They don't provide much insulation though.

      Reply

  29. Winged Lady says

    We have mold in our home, and are going to build a tiny home in the backyard to stay in while we do remodeling and tent for termites. We will be building a "Quonset Hut" of about 425 sq feet. It is a tunnel type of structure with either teardrop or rounded roof, all made of steel, coated in "Galvalume". To prevent condensation, spray foam is recommended as an insulation. Which of these would work best in a metal building? Not sure what "moisture barriers" are in relationship to insulation, as I see people mentioning above. I certainly don't want to invite more mold growth! We live in S. Florida. I am a sensitive. Thank you!

    Reply

    • Corinne says

      Hi, I can't give technical advice but there is a reason they suggest spray foam as it's the least likely to cause condensation if you heat the place in winter. If you don't heat the place you have more options. Consult with a building science expert if not sure. You can also read articles on Green Building Advisor which will give you the basics on condensation and vapour barriers (you have an exterior vapour barrier when you have a metal wall on the exterior with no rain screen).

      Reply

  31. Unknown says

    Hi Corinne, Thanks for this incredibly valuable info! You wrote: "Instead of using spray foam around windows and doors you can fill in the gaps with Backer Rod and seal with non-toxic silicone." 1) Do you recommend one type of backer rod over another? Did you choose the backer rod in the link because it has special non-toxic qualities? 2) I'd really like to avoid the isocyanates in Handi Foam (http://www.fomo.com/Data/Sites/1/Assets/ModuleDependencies/csFomoMediaView/Media/%20A16186%20One%20Component%20PU%20Foam%20HC%20November%202015pdf.pdf). What would I lose in terms of keeping air, water, and mold out if I used backer rod and silicone instead? Thank you in advance for considering my question!!

    Reply

  32. Trisha says

    Unfortunately many of us with MCS are also financially strapped and end up in toxic environments because we can't afford to live in a chemical-free home….it's not a cheap disease to have. I have half-torn-up floors in my mobile home because it would cost me nearly $10,000 USD to replace them all and I live on disability. At least I had the soft spots fixed, but it would be nice to have floors again instead of only subflooring. I can use real hardwood, real linoleum, or cork squares. None of it is cheap by any stretch of the imagination. To do 1100 square feet with underlayment, other supplies, and labor is almost as much as I live on in a year. Many of us find ourselves in similar situations. Instead, I use throw rugs to cover the worst spots and rarely have people over because it's embarrassing to have such a messy floor. However, I had to have the floors repaired or risk falling through one of the soft spots.

    Reply

  33. American Rockwool says

    How about Rockwool Premium Plus from American Rockwool. This Rockwool has zero chemical additives. It is made as a loose fill material so there is no need to add any binders. High R value at 4.13/inch, non-combustible, inorganic and is excellent at sound deadening.

    Reply

  34. Brooke says

    I just want to say thank you for all your hard work on this blog and sharing your knowledge! I am building a house and constantly refer back to your website. I have found most the Green websites to be junk as they promote recycled products as opposed to non-toxic, low VOC.

    Reply

  35. Unknown says

    We used Reflectix insulation in a trailer and two tiny homes in a cold climate with great results. It was labeled r-14 for double bubble 3/4". I believe it! It is most effective with an air gap on one side or both sides (not sandwiched tightly between two other layers.) It is even better in the horizontal position, floor and ceiling, but be careful to ventilate the room properly, because reflectix is a complete moisture barrier.

    Reply

  38. Unknown says

    So many options!! We need to choose one for our basement. My husband wants soundproofing so we don't hear everything from upstairs. I don't want any toxins if possible. We are not chemically sensitive, just like to live as clean as possible. Can you suggest which of these will do the job for us?

    Reply

  39. Mike B says

    Is there polyester insulation in Canada? It's rather popular in au and nz. But not so popula in Canada, usa and Europe. Why? Do you know?
    Regards, Mike

    Reply

  42. Bill Baggins says

    I would tend to think that a wool bat might be a more common option for people, but I don't know a lot about insulation types. However, I liked when you mentioned that materials are going "green" more, it seems like that might appeal more the the general populace. Nowadays with technology and different manufacturing, it seems like there are more options for those who want an eco-friendly solution. Thanks for the information. http://www.allweathershieldpa.com/services.html

    Reply

  43. ruby says

    Do you suggest a vapor barrier such as tu-tuff under the Eva and against the outside wall if attaching to a fiberglass shell trailer wall or on top of an aluminum tread floor? Would that help condensation? Should i apply reflectix first in order to have a better R value?

    Reply

  45. Leslie says

    Good Shepherd wool insulation had latex as I binder last time I checked. (It was _very_ difficult to get the owner of the company to admit this, but after checking out a sample it was very clear to me there was something in there besides wool, and he finally admitted it was latex.) I had talked with Shepherd's Dream about getting some wool that was really just wool (they are a very eco-minded company, and I consider them trust-worthy). I ended up going with Latitude brand. It has boric acid, and an acrylic binder. Acrylic is much more tolerable for me than latex, and boric acid doesn't seem to pose any MCS-related problems. (As Corrine said, don't eat it or breathe it, and you will probably be okay with it, as it does not put of any VOC's.)

    Reply

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