How Composite Wood Saves Trees But Harms Our Health—But Doesn't Need To.
When we think of wood, we often picture solid planks or logs. But much of the wood we use today is composite wood made up of many different pieces stuck together. Composite wood products are engineered materials made from wood fibers, chips, or veneers bonded together with adhesives to form sheets or panels. These products include plywood, particleboard, chipboard, oriented strand board (OSB), and medium-density fiberboard (MDF).
For larger construction projects, "mass timber" is becoming popular, where larger structural wood members are created by gluing or fastening smaller pieces together.
Composite wood products allow wood that would otherwise be wasted to be put to use, which maximizes the amount of useful wood we can get out of a tree. It's a more sustainable use of wood than just using dimensional lumber, but typically it comes at the cost of indoor air quality and health from toxic binders.
There are several reasons why composite wood has become so widespread: it reduces waste and maximizes resources, it's cheap, it's strong and workable, and it's versatile.
Traditional woodworking and lumber production generate a massive amount of sawdust, wood chips, and scrap wood. Instead of letting these materials go to waste, composite wood manufacturers press them into new, functional materials. This means that even low-quality wood sources, like small branches or sawmill scraps, can be turned into useful products.
Solid wood is expensive and resource-intensive, but composite wood products are cheaper and more accessible. Builders and furniture makers can get high-quality, durable panels at a fraction of the cost of solid hardwood or softwood.
While some composite wood products (like MDF and particleboard) are not as strong as solid wood, others, like plywood and OSB, rival solid lumber in strength. With wood grains going in different directions in multiple layers, the likelihood of splitting is reduced. And if a split does occur in one layer, from a screw or nail for example, the other layers hold the sheet together. Composite panels are also uniform in texture and dimension, making them easy to cut, shape, and paint.
From subflooring and wall sheathing in homes to furniture, cabinetry, and decorative paneling, composite wood products are found everywhere in construction and manufacturing.
Types of Composite Wood Products
Material | Composition | Common Uses | Strength & Durability | Moisture Resistance |
Plywood | Thin wood veneers glued together in layers | Construction, furniture, marine applications | High | Good for exterior grades |
OSB (Oriented Strand Board) | Large wood strands arranged in layers | Roofing, walls, flooring | Medium-high | Good if treated |
Particleboard | Small wood particles bonded with resin | Low-cost furniture, countertops | Low | Poor unless treated |
Chipboard | Coarser wood chips pressed into sheets | Temporary structures, furniture backing | Lower than particleboard | Poor |
MDF (Medium-Density Fiberboard) | Fine wood fibers compressed with adhesive | Furniture, molding, cabinetry | Medium | Poor unless treated |
How They're Made:
Plywood is one of the most expensive composite wood products because it's made from whole logs. A machine removes the bark from the log, then another machine spins the log and shaves off a thin layer to form a continuous ribbon of wood. These "veneers" are then stacked and glued together at 90 degree angles. This allows for the use of fast-growing cheaper woods to be used in the middle layers, and slower growing expensive hardwoods on the outer layers. This way the look and feel of hardwood can be achieved for cabinet and furniture making at a fraction of the cost and in a more sustainable manner than using solid hardwood boards.
If you've never seen how plywood is made, it's wicked cool!
OSB is made in a similar way but instead of slicing the logs into veneers, machines cut the wood into small pieces. These then get glued and pressed together with heat and pressure. Since smaller logs can be used, OSB is cheaper than plywood.
Video: How OSB is made.
Particle board and chipboard are even cheaper because they're made of mostly waste woodchips, shavings, and sawdust bonded together with different binders. Often sheets of particle board have some sort of laminate layer glued to the outside to improve the appearance, durability, and moisture resistance.
Video: How particle board is made.
MDF is made from small logs similar to OSB. The logs are ground up into a fine mixture resembling sawdust. Then it's mixed with waxes and binders before being formed into sheets and heated and pressed together.
Video: How MDF is made.
Health Effects of Composite Wood Products
One of the biggest concerns with composite wood products is their reliance on adhesives that contain formaldehyde, a volatile organic compound (VOC) with known health risks. Different types of binders contribute to varying levels of emissions. Urea-formaldehyde (UF), commonly found in particleboard, indoor plywood, and MDF, is known for high VOC emissions and is the most concerning for indoor air quality. Phenol-formaldehyde (PF), used in outdoor plywood and OSB, emits fewer VOCs than UF but still contributes to formaldehyde exposure. Melamine-formaldehyde (MF), often used in moisture-resistant MDF and particleboard, falls between UF and PF in terms of emission levels.
Exposure to formaldehyde can lead to both short-term and long-term health effects. In the short term, people may experience eye, nose, and throat irritation, headaches, and respiratory symptoms (NIH, 2023). Long-term exposure, particularly in high concentrations, has been linked to an increased risk of nasopharyngeal cancer and leukemia (EPA, 2023).
Beyond formaldehyde, composite wood products may also release other VOCs and toxins. Some materials contain solvent-based adhesives, laminates, and finishes, which can off-gas harmful chemicals over time. Additionally, flame retardants, used in some MDF and particleboard formulations, have raised concerns about potential endocrine disruption and toxicity. These toxic binding agents also make composite wood products difficult to reuse or recycle.
Cutting or sanding any of these composite wood materials releases fine dust containing both the wood and the binders, which can cause lung irritation and other health issues.
Next time you're anywhere in your house, look around you. It's likely that you're surrounded by composite wood products. There's probably OSB or plywood under your flooring, on your roof deck, and all of your exterior walls. Your cabinets and furniture are probably made of MDF, particleboard, or plywood. While they're fantastic and cheap building materials, they can be off-gassing formaldehyde and ruining your indoor air quality.
The U.S. heavily relies on composite wood products across various industries, from construction to furniture manufacturing. Each year, approximately 7.14 million cubic meters of medium-density fiberboard (MDF) are consumed, reflecting its widespread use in cabinetry and interior paneling (USDA, 2023). Similarly, oriented strand board (OSB) sees nearly 1 million cubic meters of annual consumption, primarily in residential and commercial building applications (USDA, 2023). Particleboard, another commonly used material in affordable furniture and countertop substrates, accounts for around 1.5 million cubic meters per year (CORRIM, 2018).
While specific U.S. data on plywood is more limited, global plywood consumption was reported at 155 million cubic meters in 2016, suggesting significant domestic use as well (Global Wood, 2018).
What's The Alternative?
It would be a mistake to do away with composite wood products because they efficiently use wood and, therefore, reduce the amount of land required for tree plantations, preserving natural forests. They also reduce the cost of construction and anything made of wood since it can be made into large sheets easily. A 3/4" thick 4'x8' sheet of plywood costs around $70 and requires a tree that's only 40 years old, whereas a solid piece of even a cheap softwood that size would cost around $1,500 and require a tree several hundred years old.
The good news is that safer, formaldehyde-free composite wood products do exist! These use alternative binders that are non-toxic and sustainable.
Healthier Binders for Composite Wood
As concerns over formaldehyde emissions grow, manufacturers have begun developing healthier, more sustainable binders for composite wood products. One of the most promising alternatives is soy-based adhesives, which are derived from soy protein and completely eliminate formaldehyde. This technology is already in use, with Columbia Forest Products leading the way through their PureBond® plywood.
Another innovative option is lignin-based resins, which replace synthetic chemicals with natural wood polymers. These resins are being explored in projects like Fraunhofer’s LowEPanel, demonstrating the potential for truly bio-based adhesives.
Beyond lignin, bio-based binders are being developed from renewable sources such as carbohydrates, proteins, and plant oils. One example is DuraBind™ by EcoSynthetix, which provides a sustainable, formaldehyde-free solution for MDF and particleboard production.
Another option, PMDI (Polymeric Methylene Diphenyl Diisocyanate), is a formaldehyde-free synthetic binder that emits fewer VOCs than traditional adhesives and is commonly found in low-VOC OSB products. While not entirely natural, PMDI-based adhesives offer a significant reduction in harmful emissions compared to conventional UF resins.
Where to Buy Formaldehyde-Free Composite Wood
Major retailers like Lowe’s and Home Depot now carry no-added-formaldehyde (NAF) composite wood products, making it easier than ever to choose healthier, more sustainable materials. With increasing awareness and demand, formaldehyde-free composite wood is becoming more available, offering a safer choice for homeowners, builders, and manufacturers alike.
The Future of Composite Wood
Composite wood products help reduce waste, lower costs, preserve forests, and provide a stable material for furniture and construction. However, traditional binders release harmful VOCs that can affect indoor air quality and long-term health.
Fortunately, safer alternatives are available. By choosing formaldehyde-free, bio-based binders, we can enjoy the benefits of composite wood without the toxic side effects. As a consumer or breathing human, you can purchase these healthier alternatives and request that they be used if you're building or remodeling your home. As more manufacturers adopt these eco-friendly solutions, the future of engineered wood will become healthier and more sustainable.
Questions for you:
How much thought do you give to the materials used in your home and furniture?
Is it time for stricter regulations on the use of harmful adhesives in composite wood products?
How can we balance the benefits of reducing wood waste with the need to protect human health?
Resources:
California Air Resources Board. (2023). Composite Wood Products Program. https://ww2.arb.ca.gov/our-work/programs/composite-wood-products-program
U.S. Environmental Protection Agency. (2023). Formaldehyde Emission Standards for Composite Wood Products. https://www.epa.gov/formaldehyde
National Institutes of Health. (2023). Health effects of formaldehyde exposure. https://www.ncbi.nlm.nih.gov/books/NBK597627/
Columbia Forest Products. (2023). PureBond® Hardwood Plywood. https://www.columbiaforestproducts.com/product/purebond-hardwood-plywood
USDA Forest Service. (2023). U.S. MDF and OSB consumption trends. https://research.fs.usda.gov/treesearch/8881
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