The NTP and IARC also considered that there is sufficient evidence for the carcinogenicity of formaldehyde in experimental animals on the basis of studies in which nasal tumors were formed in rats and mice following chronic exposure to formaldehyde. Formaldehyde produced genetic changes in a variety of standard tests. Exposure to formaldehyde vapor at concentrations in excess of 1 ppm may cause significant irritation of the eyes and respiratory tract. The irritation threshold appears to be 0.3 ppm. No pulmonary sensitization has been demonstrated in laboratory studies.
Formaldehyde solutions can cause severe eye and moderate skin irritation.
Formaldehyde was found to be weakly active in a number of in vitro genotoxicity test, but inactive in vivo. Formaldehyde did not cause birth defects in rats inhaling concentrations up to 10 ppm. Lifetime inhalation of formaldehyde vapor at concentrations above 5 ppm for 6 hours per day, caused nasal tumors in laboratory animals. Many epidemiology studies have failed to link cancer in humans with occupational exposure to formaldehyde. 4025 Willowbend Blvd.