Toxicology and carcinogenesis studies of vinylidene chloride in F344/N rats and B6C3F1/N mice (inhalation studies).

Vinylidene chloride is used as an intermediate in organic synthesis reactions and is widely used in the production of a variety of polymers. Most of the vinylidene chloride in the plastics industry is used in the production of copolymers with polyvinylidene polymers that have a broad spectrum of application, including in films for household and industrial food packaging, as coatings on a variety of products, in flame-resistant fiber and carpet backing, as binders in paints, and to fabricate filaments, pipes, pipe liners, and gaskets. The highest potential for human exposure to vinylidene chloride is at its point of production and formulation, and occupational exposure may occur via inhalation or dermal contact. The general population is exposed via inhalation and ingestion of contaminated drinking water. Vinylidene chloride was nominated for study by the Agency for Toxic Substances and Disease Registry because of the potential for human exposure, and because there was insufficient critical information concerning its health effects and a need to fill critical data gaps. Male and female F344/N rats and B6C3F1/N mice were exposed to vinylidene chloride (greater than 99.9% pure) by inhalation for 2 weeks, 3 months, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Escherichia coli, L5178Y mouse lymphoma cells, Drosophila melanogaster, and mouse peripheral blood erythrocytes. (Abstract Abridged).