A two-generation reproduction study in rats receiving drinking water containing vinyl acetate.

Vinyl acetate (VA) is a commonly used chemical in polymerization and copolymerization processes and as a chemical intermediate. As part of a collaborative effort between VA producers of the United States and British Petroleum, the present study was carried out to provide a base set of data for risk assessment. Groups of male and female Crl:CD(SD)BR rats were given 0, 200, 1000, or 5000 ppm VA via the drinking water over two generations. In addition, a cross-mating trial of control and 5000-ppm male and female rats was conducted in the F1 generation to investigate the slightly decreased litter production in the high-dose group. No treatment-related mortality was observed in any of the groups. Water consumption was significantly reduced in the 5000-ppm groups in both generations and in the 1000-ppm F1 female rats. The body weights of the F0 and F1 male rats and the F1 female rats in the 5000-ppm group tended to be slightly lower than those of the control group. Body weight gain was significantly decreased during lactation in the F0 females at 5000 ppm and in the F1 females at 1000 and 5000 ppm. Pup weights in the F1 generation, but not in the F2 generation, were significantly lower than those of the control on lactation Day 21. The number of litters produced in the F1 generation in the 5000-ppm group was slightly lower than that of the control group and was attributed to lower fertility. Fewer pups were produced when control females were mated with the 5000-ppm males; however, the decrease was due to poor mating performance rather than decreased fertility. No decrease was apparent when the 5000-ppm females were mated with the control group males. Under the conditions of this study, the no-observed adverse effort level was considered to be 1000 ppm.