Fundamental Toxicological Sciences

Paper Details

Fundamental Toxicological Sciences
Vol. 8 No. 4 August 27, 2021 p.103-116
Original Article
Repeated-dose and reproductive/developmental toxicity screening of polyoxymethylene in rats
  • Mariko Matsumoto (Division of Risk Assessment, Biological Safety Research Center, National Institute of Health Sciences / mariko@nihs.go.jp)
Mariko Matsumoto 1) , Sakiko Fujii 2) , Nozomu Hirose 1) , Takako Iso 1) , Yoshiyuki Shigeta 1) , Yasumasa Murata 1) , Kaoru Inoue 1) , Akihiko Hirose 1)
1) Division of Risk Assessment, Biological Safety Research Center, National Institute of Health Sciences , 2) Safety Research Division, Safety Research Institute for Chemical Compounds Co., Ltd.
Keywords: Polyoxymethylene, Paraformaldehyde, CAS No. 30525-89-4, Chemical substances control law, Existing chemical substance, Formaldehyde
Abstracts

>The Japanese government requires risk assessment of chemicals under the Chemical Substances Control Law (CSCL). Toxicity data for polyoxymethylene (paraformaldehyde; CAS No.: 30525-89-4) for human health are insufficient though the chemical needs a screening assessment under the CSCL. Thus, polyoxymethylene was selected by the Safety Examination of Existing Chemicals and Safety Programmes of the Ministry of Health, Labour and Welfare (MHLW) to assess repeated-dose and reproductive/developmental toxicity. A combined toxicity screening was conducted following the OECD TG422. Male and female rats were administered the test chemical once daily by gavage at doses of 0 (control), 20, 60, or 200 mg/kg bw from 14 days before mating for a total of 28 to 61 days. The 200 mg/kg bw/day dose caused a significant decrease in food consumption. Histopathological examination found ulcers in the forestomach and glandular stomach, and erosion and inflammatory cell infiltration in the submucosa of the glandular stomach at the end of dosing in both sexes. Inflammatory cell infiltration in the submucosa of the glandular stomach was also observed in both sexes after the recovery period. No reproductive and developmental toxicity was observed even at the highest dose. A no-observed-adverse-effect level (NOAEL) for repeated-dose toxicity was 60 mg/kg bw/day, and a NOAEL for reproductive and developmental toxicity was 200 mg/kg bw/day, the highest dose tested.