Formaldehyde is produced on a large scale worldwide. One major use includes the production of wood binding adhesives and resins. The Air Resources Board (ARB) evaluated formaldehyde exposure in California and found that one of the major sources of exposure is from inhalation of formaldehyde emitted from composite wood products containing urea-formaldehyde resins. The International Agency for Research on Cancer (IARC) reclassified formaldehyde from "probably carcinogenic to humans" to "carcinogenic to humans" in 2004, based on the increased risk of nasopharyngeal cancer. Formaldehyde was also designated as a toxic air contaminant (TAC) in California in 1992 with no safe level of exposure. State law requires ARB to take action to reduce human exposure to all TACs.
Staff of the ARB conducted a formal rulemaking process to address formaldehyde exposure from composite wood products. On April 26, 2007, ARB approved an airborne toxic control measure (ATCM) to reduce formaldehyde emissions from composite wood products including hardwood plywood, particleboard, medium density fiberboard, thin medium density fiberboard (thickness ≤ 8mm), and also furniture and other finished products made with composite wood products. The ARB's April 26, 2007 Board Presentation is available.
The ATCM to control formaldehyde emissions from composite wood products was approved on April 18, 2008, by the Office of Administrative Law. The regulation has been filed with the Secretary of State to be codified into Title 17 of the California Code of Regulations, and is now immediately effective. The first emission standards were implemented on January 1, 2009. The final regulation text is now available.