There is sufficient data from toxicokinetic studies in humans [Feldman and Maibach 1974; Wester et al. 1985; Franklin et al. 1989; McCurdy et al. 1994] and animals [Franklin et al. 1989; Thongsinthusack 1999] to demonstrate that azinphos-methyl can be absorbed through the skin and is systemically available. Acute dermal toxicity data from animals [Gains 1960; Sato 1959; Pasquet et al. 1976] and a case report [Quinby et al. 1958] indicate that azinphos-methyl can be fatal following exposure at low doses. No prolonged, repeated-dose dermal toxicity studies were identified, but azinphos-methyl inhibits AChE in the central and peripheral nervous systems, as is observed in oral toxicity studies in rats [Sheets 1994]. No case reports or standard skin irritation tests in animals were identified for determining the potential of azinphos-methyl to cause direct skin effects. No diagnostic tests in humans or case reports of sensitization were identified, but a well-conducted Buehler patch test on guinea pigs indicates that azinphos-methyl has the potential to cause skin sensitization [Bayer AG 1987]. Therefore, on the basis of these assessments, azinphos-methyl is assigned a composite skin notation of SK: SYS (FATAL)-SEN. Table 3 summarizes the skin hazard designations for azinphos-methyl previously issued by NIOSH and other organizations. The equivalent dermal designations for azinphos-methyl, according to the Globally Harmonized System (GHS) for the Classification and Labelling of Chemicals, are Acute Toxicity Category 3 (Hazard statement: Toxic in contact with the skin) and Skin Sensitization Category 1 (Hazard statement: May cause an allergic skin reaction) [European Parliament 2008].

Suggested citation: NIOSH [2015]. NIOSH [2015]. NIOSH skin notation profile: Azinphos-methyl. By Hudson NL, Dotson GS. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publi- cation No. 2015-235.

NIOSHTIC No 20046851

f15_snp_2015-235.pdf

Stephen B. Thacker CDC Library collection