Information on the carcinogenicity of formaldehyde (50000) is reviewed. The physical characteristics, and the methods of production and uses of formaldehyde are discussed together with estimates of the extent of industrial exposure. OSHA standards for occupational exposure, which mandate 0n 8-hour time weighted average of 3 parts per million (ppm) and a 5ppm ceiling, are summarized. Evidence for formaldehyde's toxicity, mutagenicity, and other health effects in humans and laboratory animals is evaluated. Occupations involving formaldehyde exposure, ranges of occupational exposure by industry, major formaldehyde manufacturers, and guidelines for reducing employee exposure, are listed. The author concludes that formaldehyde should be treated as a potential human carcinogen, and recommends that control measures to reduce employee exposures be instituted.