Abstract
α-(nonylphenyl)-ω-hydroxypoly(oxyethylene) (NPE) has been identified as a Priority Assessment Chemicals #86 (#86) under the Chemical Substances Control Law due to its ecotoxicity. In this study, we evaluated general toxicity, developmental and reproductive toxicity, genotoxicity, and carcinogenicity of NPE for a screening assessment. The #86 comprises 32 substances with diverse structures varying in the number of ethylene oxide moles, the carbon chain structure of the nonyl group and the substitution position of the nonyl group on the aromatic ring. We assessed NPE using toxicological data of polyoxyethylene nonylphenyl ether (CAS RN.9016-45-9) as a representative substance, for which most data were about in #86. In addition, we assessed the effect of isomeric mixtures of nonylphenol (NP), which are degradates of NPE in the environment, and selected the most severe hazard class between NPE and NP as representative for #86. Based on the general toxicities observed in 2-year feeding studies with rats and dogs, the hazard class for NPE was determined to be 4. The hazard class for NP was determined to be 3, based on the general toxicities observed in a 28-day oral study with rats. Accordingly, the hazard class of 3 was selected as representative for #86. (Please note that this assessment is based on our own considerations and is not directly related to any administrative decisions made by the Ministry of Health, Labour, and Welfare.)
