DHHS publication ; no. (NIOSH)

The available toxicokinetic data from studies of methyl parathion absorption in humans [Muttray et al. 2010] and rats [Abu-Qare et al. 2000a, 2000b; Kramer et al. 2002] and from in vitro studies [Sartorelli et al. 1997; Van der Merwe and Riviere 2006] indicate that methyl parathion can be absorbed through the skin. Acute toxicity studies in rats [Gaines 1960], occupational exposure studies [Nemec et al. 1968; Ware et al. 1975; Wolff et al. 1992], and repeated-dose and subchronic toxicity studies in rats [Zhu et al. 2001; Ma et al. 2003] indicate the potential to cause systemic effects, including ChE inhibition, central nervous system effects, and lethality. No standard skin irritation tests were identified to evaluate the potential of methyl parathion to be a skin irritant. Human diagnostic patch tests indicate that methyl parathion is not likely to be a skin sensitizer. Therefore, on the basis of these assessments, methyl parathion is assigned a composite skin notation of SK: SYS (FATAL). Table 3 summarizes the skin hazard designations for methyl parathion previously issued by NIOSH and other organizations. The equivalent dermal designation for methyl parathion, according to the Globally Harmonized System (GHS) for the Classification and Labelling of Chemicals, is Acute Toxicity Category 3 (Hazard statement: Toxic in contact with the skin) [European Parliament 2008].Suggested citation: NIOSH [2015]. NIOSH skin notation profile: Methyl parathion By Hudson NL, Dotson GS. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Pre- vention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2015-231.NIOSHTIC No 20046845f15_snp_2015-231.pd