A Guide to Choosing Pressed, Engineered and Laminated Wood Products and their Formaldehyde and VOC Levels.
This post will cover pressed wood and laminated wood (engineered wood) products used in construction and in household items like furniture and doors.
We will look at which adhesives are used and what chemicals they offgas. Formaldehyde levels will be noted, as they vary between engineered wood types. But not all engineer wood is pressed together with formaldehyde.
I will also note which wood species are commonly used.
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.
Overview of the Adhesives Used in Engineered Wood Products
Methylene diphenyl diisocyanate (MDI) – offgasses methylene diphenyl diisocyanate, though the companies claim this cures into a polyurethane.
Phenol-Formaldehyde (PH) – 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.
Urea-Formaldehyde (UF) – 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.
No added Urea Formaldehyde (NAUF), this almost always means PF is used.
No Added Formaldehyde (NAF), this means no formaldehyde is added to the product. They cannot be labeled “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 co-inventor 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 Levels for Formaldehyde
CARB II – Formaldehyde Levels
CARB II is a standard set by California for products sold there, but almost all 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 interior use.
It does not include exterior sheathing products like exterior plywood (softwood plywood) and OSB.
(The allowable limits for TSCA Title VI are the same as CARB).
CARB II Formaldehyde Limits Are:
|Hardwood Plywood||0.05 ppm (parts per million)|
|Medium-Density Fiberboard (MDF)||0.11 ppm|
|Thin MDF||0.13 ppm|
E-0 E-1 and E-2 European Formaldehyde Levels
E-1 certifies that boards release less than 0.1 ppm (parts per million) of formaldehyde; for E-2 boards 0.1 ppm and 0.3 ppm; and E-0 is 0.07 ppm.
M1 and M2 European Formaldehyde Levels
Formaldehyde emissions: M1 ≤ 0.05 mg/m2h and M2 ≤ 0.125 mg/m2h. This is not a straightforward conversion to ppm or µg/m3 because we need to know the size of the room, size of sample, and air exchange.
M1 could be as high as 100 µg/m³ or 0.08 ppm is the sample is large like wall boards on all walls. It could be 40 µg/m³ or 0.03 ppm for flooring products. M2 would be 100 µg/m³ or 0.08 ppm for flooring products.
European A+ A B C Label
Formaldehyde C≥ 10µg/m3, B< 10µg/m3, A < 5µg/m3, A+< 3 µg/m3 (source)
GreenGuard and GreenGuard Gold Formaldehyde Levels
GreenGuard allows 0.05 ppm (parts per million) formaldehyde (61.3 μg/m3) and GreenGuard Gold allows 0.0073 ppm formaldehyde (9 μg/m3)
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
|0.0002-0.006 ppm||Rural and suburban outdoor air (source)|
|0.0015-0.047 ppm||Urban outdoor air (source)|
|0.0073 ppm||GreenGuard Gold levels for products in a room|
|0.020-4 ppm||Average levels in conventional homes/indoor air (source)|
|0.04 ppm||Canada long-term exposure 8-hour average exposure limit|
|0.05 ppm||GreenGuard levels for products; CARB target level within a home|
|0.08||WHO guidelines for exposure|
|0.10 ppm||Upper 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 ppm||OSHA 8-hour time-weighted average (TWA) action level workplace limit|
|0.80 ppm||Level at which most people first detect odor|
|56 ppm||PAC-3 (Protective Action Criteria), AEGL-3, 60 minute Acute Exposure Guideline|
Wood Products & Adhesives
Plywood (Interior and Exterior)
Which Chemicals Does Plywood Offgas?
Exterior grades of plywood are used for roof sheathing, subfloor, and roof decking.
Exterior grades of plywood are made with phenol-formaldehyde as the binder/glue. Plywood is made with 3.5% formaldehyde. Phenol formaldehyde is the least toxic type as it offgases less and it offgases faster.
Exterior plywood is also be called structural plywood or softwood plywood (SWPW).
Type of wood
It is made of softwood, (usually fir, spruce and/or 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.
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 it 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 about 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 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.
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 is commonly is treated with alkaline copper quaternary (i.e. 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 rare nowadays and it’s definitely not often used in residential buildings.
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 or NAF glues, not UF.
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 tell us much about what it will offgas in the end, only what went into it.
I have seen chemically sensitive folks react to this brand of plywood so I would make sure to test it out yourself before using it.
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 MDF Offgas?
MDF is often made with urea-formaldehyde which offgasses more than phenol-formaldehyde. MDF is composed of 10% formaldehyde, but because of its density, it’s slower to offgas than plywood or particleboard.
Where it’s used
You will find MDF in many cabinets, solid-core and hollow core doors, furniture, and as part of some flooring types. MDF is also used in baseboards and other trim which can easily be swapped out for solid wood.
My posts on kitchen cabinets, furniture, doors, and flooring provide alternatives.
Glues and offgassing
The level of formaldehyde offgassing is higher 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.
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.
The main alternative glue is MDI.
See my post on formaldehyde-free MDF for brands.
Oriented Strand Board (OSB)
Which Chemicals Does OSB Offgas?
OSB is usually made with phenol-formaldehyde (PF) and MDI adhesives. MDI is the primary adhesive in OSB usually.
Though they claim the MDI fully cures into a polyurethane, there is evidence MDI offgases isocyanates. I certainly pick up the offgassing for months.
Where is it used
OSB is often used in house sheathing: roof sheathing/decking, exterior wall sheathing, and as subfloors.
Usually OSB and plywood can use used interchangeably for applications in a building.
Sensitive folks usually choose plywood over OSB, but some brands of OSB listed below can be very good.
A common type of OSB is the Huber Advantech. I find these need a solid 4 months to offgas to my standards (a lot longer than plywood).
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 stamped OSB which will not contain UF.
There is no added formaldehyde (“formaldehyde-free”) OSB, but it’s harder to source.
Particleboard/Low-Density Fiberboard (LDF)
Which Chemicals Does Particleboard Offgas?
Urea-formaldehyde (UF) (the type that offgasses more and for longer) is usually used as the adhesive in particleboard, which is also called furniture board. You may also see MDI used.
Particleboard is made with 12.4% formaldehyde, however because it’s lower density than MDF or HDF, it does offgas a little bit faster in my experience.
Where is it use
Particleboard is commonly used in cabinets and to make furniture. It is often used to make shelving and for structure in inexpensive beds and sofas.
When the material is listed as “laminate” this is particle board with a melamine plastic laminated onto it like in the picture above.
For safer options, see my posts on healthier cabinet options, furniture, sofas, and sealing in the offgassing in your particleboard.
High-Density Fiberboard (HDF)
Which Chemicals Does HDF Offgas?
Hardboard/HDF/fiberboards could be made with either phenol-formaldehyde, urea-formaldehyde, or melamine formaldehyde.
Paraffin wax and a small amount of ammonia are typical additives. Linseed oil can be added to some types.
HDF is used in the substrate of many floorings like Marmoleum Click, some cork flooring, and laminate flooring (you can identify whether you have flooring with HDF by checking out this post).
It is also used to make Masonite and other brand hollow core doors (as the skin).
It’s often found as the backing to furniture, like dressers, bookcases, and cabinets. Pegboard (pictured above) is also made from HDF.
When used as a backing to furniture it’s easy to seal in almost all of the formaldehyde with shellac.
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/TJI Joists are made with PF and MDI glues.
- Cross-laminated timber can be made with a variety of different glues: polyurethane, polycarbonate, 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 claim to be lower-emitting than typical OSB
Cost comparison of OSB, plywood, and Advantech Sheathing.
Corinne Segura is a Building Biologist with 8 years of experience helping folks 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!
We are looking to build out a lot of closets and built ins in our home and for
1. The closets I have 2 companies – first uses carb 2 complaint melamine particle board but made with urea formaldehyde resin. The second if tcsa title vi compliant melamine particleboard. I don’t know the resin they use. Would you recommend one over the other?
2. For The other built ins and crown moulding etc. our contractor said he’ll use birch plywood – is that good? What else should I be asking him regarding this?
Thanks so much!!
these Qs are answered in the article
Hi – i just got kitchen cupboards that are 3/4″ plywood covered with an mdf material that has what looks like melamine on both sides. If the exposed areas of the mdf which are just along the edges, are covered by a wall or countertop will that stop the off gassing? And if so, what happens to the gases?
Ilse Gagnaire says
Unfortunately, we had mdf installed through out much of our main floor for trim and baseboards, and then painted prior to me realizing how much it off gasses (and how sensitive to smell I am). I don’t really experience any health impacts, other than the smell. I tried a sample of shellac over an extra board we have and it looks glossy. Questions about sealing- is it the same for boards that have already been installed/painted? Need to figure out how to make it non glossy.
the easiest way for someone not sensitive is BIN shellac (the alcohol-based one) let that offgas, then paint.
Ken Bos says
Corinne – Thanks for all of your informative posts. I am currently looking at building a new house. I noticed a popular you-tube builder had a chemically sensitive client paint the interior of a new build in the sequence before electrical/insulation/plumbing/drywall. They did all of the interior stud walls, floor, ceiling etc. This was intended to encapsulate the VOC’s that occur with many of the modern building products such as the osb inner side of Huber zip. They mentioned mixing kaolin clay powder with the paint to assist with the mitigation/encapsulation. It obviously needed to be sprayed on for effective coverage. I believe they used a lime wash paint similar to Romabio. I have read some of your informative writing regarding paints. What would be your recommendation for a paint for this application?
I wouldn’t recommend that, so I can’t recommend a paint for that application.
Thank you for this informative article and Happy 2023! We have an 11 year-old bed set (made in Mexico, if that makes a difference) that has solid wood construction in some areas, as well as areas with Particleboard/Low-Density Fiberboard (LDF) and Oriented Strand Board (OSB). How long does it take for the LDF and OSB to off-gas entirely (or, if this is not possible, at least to well-below safe limits)?
it should be off gassed at 11 years.
Thank you for your response! I appreciate it!
One more question: We have a 7 year-old spring mattress made of 30% Urethane Foam (as well as some Polyester Fiber and Cotton Fiber)? How long does Urethane Foam in mattresses take to off-gas completely (or to safe limits)? I am asking because we want our young son to sleep on it, but not if it is still off-gassing.
polyurethane foam is offgassed at 7 years, though I would try to check if it has flame retardants which will continually leach out.
Ashley Cossé says
I appreciate your blog and the information you provide. Is a certain type of moulding better to use for crown and baseboards? I know you said solid wood is better than MDF but should I look for anything else when purchasing?
Just solid wood
Thank you so much for your blog! So very helpful when building a new home! for the kitchen/cabinets in my new home I am unsure whether to go with a very low emission MDF (Super E0) or a plywood made with phenol formaldehyde and rated E1. From reading your blog it seems that the plywood may start off more toxic with a higher emission rating but would off gas much quicker to negligible amounts, Whereas the MDF would start off with a lower emission rating but would stay emitting for longer. Do you have any thoughts on the best long term option? I have little kids so thinking of their health. Also the plywood companies state they use a Phenol Glue which I assume is phenol formaldehyde? I can get a soy-based glue plywood without formaldehyde but that sounds equally problematic. Thanks very much in advance.
Plywood is much better than MDF. If both are made with formaldehyde plywood is much better. If the MDF is made with a MDI glue, that is no added formaldehyde, so it will show lower formaldehyde but it off gasses other chemicals and is still worse than plywood. There is no contest there for me. There is a post just on plywood that might be helpful as well.
Thank you so much! Would you say plywood is the better choice as well for the boxes in the cabinetry or melamine/or laminate fully encasing an MDF core?
Last October we had our 70 year old roof redone down to the plywood. Unfortunately, it needed all new plywood thanks to inadequate roof ventilation. This shouldn’t be a problem going forward thanks to a new full length ridge vent. With spring, the weather has been warming up and now I’ve been noticing the distinct odor of plywood in the upstairs bedrooms. Do you think this is safe? How many years on average does it take for exterior plywood to completely off gas? I really dislike that odor.
Katie M says
I’m so grateful for your site and use it all of the time! We’re going to hire you to help build our next mold free chemical free modular home in the next few months.
Right now I’m struggling because I have Mast Cell Activation Syndrome, Mold Toxcicity. MCS, and more. I’m fully disabled since getting COVID 20 months ago and need a hospital bed style table but they’re all plastic or particle board but I’m highly reactive. Do you have any suggestions? I’m worried I’ll even react to wood if we were to use a metal base and hire someone to make a custom wood top for it.
I also am still knocked out from COVID from that same time period. It’s really tough. I haven’t looked at those tables before.
Have you ever heard of VOC or formaldehyde absorbing paints? ECOs brand offers some products that do, but I have no idea how/if they work. And would they seal in the majority of the chemicals that would be emitted while absorbing the rest. I called a rep and he said they use “zelyte crystalline”, but without a strong chemistry background I have no idea what that means. Can you shed some light?
There is zeolite in the paint which absorbs some VOCs. I talk about it in the post on paints. I have trouble seeing how that can absorb more than the VOCs that are already in the paint. Maybe a tiny bit after it dries as the zeolite can be “rechargeable” but it’s still a really small amount. In my post on where I compare sealers for offgassing this is not one that stood up well to the others.
Hello, I bought a baby furniture that claims to be CARB phase II compliant with the TECO certification letter. However, the certificate shows they use urea formaldehyde glue and the finished plywood is applied with a layer of cured epoxy acrylate. Now we are longer past the return period and after reading your article, I’m very worried to let the baby use it since it used urea formaldehyde. How concerned should I be and should I throw away the furniture? Thank you
I am planning on replacing my 30 year old laminate countertops soon but I am so totally stumped as to how to find a brand of laminate and a particle board that attaches to it that will be safe for me. I am a cancer survivor and want to try to eliminate as much exposure to chemicals as possible. Any suggestions as to which products I should try ?? Thank you!
This articles goes over the options and how to make them safer https://www.mychemicalfreehouse.net/2020/10/the-7-most-affordable-non-toxic-countertops.html
Cecil curtis says
Hi I just got cabinets installed in my kitchen from Allen and Roth by Lowe’s. Now it’s hard to breath for me. While the cabinet boxes and doors are made of plywood The shelves and other internal components are made of some engineered wood/ synthetic (unpainted) . What is your recommendation to seal off this strong oder?
If it’s internal parts I would seal it with bullseye shellac
Jolee Dawidowicz says
I had bath towels stored in my bathroom vanity cabinet and noticed they had disintegrated in several spots. Then we noticed the vanity door hinges have excessive rust on them and our sponges were totally blown apart. A plumber said it could be the chemicals leading out from the fiber board used to make the cabinet. This is a second bathroom where the shower is nearly never used so humidity is not the issue. Have you heard of anything like this ?
I’m not sure what is going on there. Formaldehyde wouldn’t do that. I’ve seen odd reactions from ozone, has that been used. I have also seen bad reactions between caulking and other materials but that’s unlikely in a bathroom. Sometimes there is another unknown reaction going on. I would do VOC testing and check for airpurifiers that use ions or ozone.
My house in New Market, Maryland we just purchased was built about 6 years ago…the outside wood trim appears to be a type of pressed/particle board with a veneer surface Why? Because when I tried to clean off the mold with a pressure washer, a small section of the surface veneer peeled off and underneath it looked like wood fibers, so it didn’t look like real wood. Real wood, such as a pressure treated wood, would not have a surface veneer that would peel off. Any idea what this wood is, and how long this wood is likely to last before it needs to be replaced
There is Masonite siding which is a fiberboard, there are plywood-based sidings and there are also OSB siding. The newest version of OSB siding is LP smart side https://www.mychemicalfreehouse.net/2019/12/non-toxic-siding-cladding.html
You need to find out more about what kind it is and also how well it was installed.
Suzanne Mark says
Thank you for that wonderful article. We just remodeled a house. It’s a manufactured home built in the 90s. We placed a MDF, pre primed, shiplap clad wall in the center of the house. Every time I go into that house my lungs are burning. Is there any way that I can get it to off-gas quickly? I am using ozone machines in that room. I’m also wondering if I can coat it with a clear No VOC coating that will “seal it“. Help!
Hi, I wouldn’t ozone it but I would seal that in https://www.mychemicalfreehouse.net/2019/05/mitigating-sealing-remediating.html
I have a 30 yr old dresser that had a sticker on back it had partial board. Will this have off gassed completely by now?
Nancy Vinton says
Does melamine coating reduce offgas from engineered wood?
Yes absolutely, it’s a very good block.
hi! we are going to put plywood over our drywall (essentially as wallpaper)…woule you use pure bond or regular plywood?
also for the user’s question above– we have a bunk bed made out of high quality plywood and because it was solid wood and we were concerned about the mattress breathing we drilled many large holes in the base for circulation.
Excellent article. I have respiratory sensitivity to formaldehyde. I want to replace my bed’s boxspring with a sheet of plywood because the combination of boxspring is just too high for the new bedframe I’ve just purchased.. What is your recommendation (type and brand)? Based on your article, my guess is Grade B exterior plywood..
a mattress needs to breathe, i would only put it on a boxpring or slats.
I have the same question. I do not want to use a boxspring. I have a latex mattress on a frame with slats but need more support (in between slats).
I would talk to the bed company because it sounds like not quite the right has for the type of mattress. See what it requires.
Depending on what type of slates they are you may be able to brace then to add extra support.