California Air Resources Board

On April 26, 2007, the California Air Resources Board approved a regulation to reduce formaldehyde emissions from composite wood products that are sold, supplied, used, or manufactured for sale in California. The regulation focuses on hardwood plywood (HWPW), particleboard (PB), and medium density fiberboard (MDF). The regulation requires that HWPW, PB, and MDF and new finished goods that contain these composite wood products meet stringent emission standards and be labeled as such.

Frequently asked questions (FAQs) are intended to assist regulated parties with complying with the formaldehyde in composite wood products regulation. Review FAQs by clicking on the specific ATCM topic in table below.

Note: Brief descriptions of terms used throughout the FAQs include:
Composite Wood
Wood products comprised of a resin matrix in combination with a wood fiber reinforcement.  Composite wood pertains to, but is not limited to, particleboard, plywood, medium density fiberboard, composite veneer and oriented strandboard.

Hardwood
The wood of a broad-leaved tree, (e.g., oak, aspen, birch etc.) either deciduous or evergreen.

Medium Density Fiberboard
A panel composed of cellulosic fibers (usually wood) made by dry forming and pressing of a resinated fiber mat.

Particleboard
A board made from non-chemically processed dry wood particles of various shapes and sizes and either synthetic or natural adhesive material.

Plywood
A board composed of a number of thin layers of veneer united under pressure by a bonding agent so that the grain of each layer is at right angles to that of the neighbor.

Veneer
Thin sheets of wood peeled or sliced from logs for use in the manufacturing of wood products such as plywood, laminated veneer lumber, or other products.

Urea-formaldehyde Resin
A thermosetting resin manufactured by heating together urea and formaldehyde.  Pale colored or water-white and translucent.  It can, therefore, take delicate dyes and tint.  It is non-flammable and is resistant to weathering and fluid attack.

Phenol-formaldehyde Resin
A thermosetting resin produced by the condensation reaction of phenol and formaldehyde.  Phenol-formaldehyde resin emits much less formaldehyde gas than urea-formaldehyde resin containing composite wood products.

See promulgated definitions in section 93120.1 of the Airborne Toxic Control Measure to Reduce Formaldehyde Emissions from Composite Wood Products for more information. 

For more information, please contact us via email at compwood@arb.ca.gov.

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