The World Health Organization last week toughened its view of the toxicity of formaldehyde and issued a warning that it is "carcinogenic to humans." Previously, WHO viewed formaldehyde as a "probable human carcinogen." The new warning stands in contrast to a recent determination by EPA under Clean Air Act regulatory provisions. In setting the air act's maximum achievable control technology standards, the agency established a standard that was less stringent by a factor of 10,000 than other EPA regulations for formaldehyde. The exposure and risk model used by EPA for the weaker standards was developed by the Chemical Industry Institute of Toxicology. EPA says it will consider the WHO findings. Formaldehyde is a widely used industrial chemical found in many chemical products, as well as building materials, insulation, permanent press fabrics, coatings, and adhesives.