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 Plywood | 0.05 ppm (parts per million) |
Medium-Density Fiberboard (MDF) | 0.11 ppm |
Thin MDF | 0.13 ppm |
Particleboard | 0.09 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
Level | Reference |
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 |
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 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?
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?
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.
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!
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
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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?
Corinne says
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 ?
Corinne says
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.
scott says
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
Corinne says
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!
Corinne says
Hi, I wouldn’t ozone it but I would seal that in https://www.mychemicalfreehouse.net/2019/05/mitigating-sealing-remediating.html
Diane says
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?
Corinne says
Yes
Nancy Vinton says
Does melamine coating reduce offgas from engineered wood?
Corinne says
Yes absolutely, it’s a very good block.
sarah says
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.
Stan says
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..
Corinne says
a mattress needs to breathe, i would only put it on a boxpring or slats.
Kate says
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).
Thanks
Corinne says
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.