NTP Technical Report on Toxicity Studies of Methyl Ethyl Ketone Peroxide (CAS No.1338-23-4) in Dimethyl Phthalate (CAS No. 131-11-3) (45:55) Administered Topically to F344/N Rats and B6C3F1 Mice

摘要

Methyl ethyl ketone peroxide (MEKP) is an unstable organic peroxide used in themanufacture of acrylic resins, as a hardening agent for fiberglass-reinforced plastics, and as a curing agent for unsaturated polyester resins. It is commercially available as a 40% to 60% solution in dimethyl phthalate (DMP). Because exposure to MEKP is typically through dermal contact, toxicity studies were conducted by topical application of MEKP in DMP to the clipped dorsal region of male and female Fischer 344/N rats and B6C3F(1) mice. Animals were evaluated for histopathology and for reproductive endpoints. In vitro genetic toxicity studies of MEKP included assessments of mutagenicity in Salmonella typhimurium and in mouse lymphoma cells, and analysis of chromosomal aberrations and sister chromatid exchanges in Chinese hamster ovary cells.