A Two-Generation Reproduction Study in Rats Receiving Drinking Water Containing Vinyl Acetate

Vinyl acetate (VA) is a commonly used chemical in polymerizationand copolymerization processes and as a chemical intermediate.As part of a collaborative effort between VA producers of theUnited States and British Petroleum, the present study was carriedout to provide a base set of data for risk assessment. Groupsof 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 maleand female rats was conducted in the F₁ generation to investigatethe 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-ppmgroups in both generations and in the 1000-ppm F₁, female rats.The body weights of the F₀ and F₁ male rats and the F₁, femalerats in the 5000-ppm group tended to be slightly lower thanthose of the control group. Body weight gain was significantlydecreased during lactation in the F₀ females at 5000 ppm andin the F₁, females at 1000 and 5000 ppm. Pup weights in theF₁, generation, but not in the F₂ generation, were significantlylower than those of the control on lactation Day 21. The numberof litters produced in the F₁ generation in the 5000-ppm groupwas slightly lower than that of the control group and was attributedto lower fertility. Fewer pups were produced when control femaleswere mated with the 5000-ppm males; however, the decrease wasdue to poor mating performance rather than decreased fertility.No decrease was apparent when the 5000-ppm females were matedwith the control group males. Under the conditions of this study,the no-observed adverse effort level was considered to be 1000ppm.