Composite Wood


Composite wood products (MDF, plywood, particleboard, PSL, OSB) are composed of wood pieces like strands, particles, fibers, or veneers. The wood is peeled or cut down to produce pieces that are glued together to create products such as framing, furniture, cabinets, flooring, and shelving.5 The glues or resins used in bonding composite wood products are often referred to as “binders”.5


Wood is generally viewed as “green,” however, composite wood often contains formaldehyde when bonded together with glue or adhesive.1


Health concerns with resins

  • Formaldehyde – When composite wood products have formaldehyde resins, they contain an unreacted substance that evaporates over time and lingers in the home.2 Formaldehyde is a carcinogen and VOC that off-gases. Formaldehyde causes nose irritation problems, lung function issues, and respiratory irritation.7
  • Isocyanate – The resin can also be made with isocyanate, a chemical that is a leading cause of asthma.

A healthy alternate is soy-based resin – which is ranked higher in the HBN spectrum.2



To combat formaldehyde in composite woods, California has issued a series of regulations. The most stringent regulatory effort to address issues with composite wood comes from CARB (California Air Resource Board) under the Airborne Toxic Control Measure.4


  • NAF (No Added Formaldehyde) under CARB utilizes no formaldehyde. NAF is labeled as the healthiest option with the highest federal standard for composite wood.1
  • ULEF (Ultra-Low Emitting Formaldehyde) standard contains low levels.2

Even if a project isn’t based in California, we can use the standards set by CARB and apply them in our specifications.


When specifying wood products: