Subchronic toxicity study in rats and genotoxicity tests with polyvinyl alcohol

The potential systemic and neurotoxicity of polyvinyl alcohol (PVA) was assessed when fed in the diet to male and female Sprague-Dawley rats for 90 days at doses of 2000, 3500 and 5000 mg/kg/day. Control rats received untreated standard laboratory diet. Assessments included clinical observations, ophthalmology, body weight and food consumption, hematology, coagulation, clinical chemistry, urinalyses, motor activity and functional observational battery evaluations and gross and microscopic pathology. The only test-article-related finding observed during the study was unformed stool with brown/black anogenital staining in rats fed 3500 and 5000 mg/kg/day. This finding was attributed to the high levels of test article being consumed and subsequently excreted in the stool. It was not accompanied by macroscopic or microscopic changes in these rats. No test-article-related changes were seen in mortality, ophthalmology, body weight and food consumption data, hematology, clinical chemistry, urinalysis data, functional observational assessments, motor activity, organ weight data and macroscopic and microscopic examinations. Doses of 2000, 3500 and 5000 mg/kg/day of PVA administered as a dietary admixture to male and female Sprague-Dawley rats for up to 90 days did not result in any adverse, toxicological effects. The no-observed-adverse-effect level (NOAEL) was determined to be 5000 mg/kg/day. PVA showed no evidence of mutagenic activity in the Ames test, mouse lymphoma assay and the mouse micronucleus test. (A critical evaluation of the available information on PVA will appear in a review to be published in Food and Chemical Toxicology 2003, 41, 319-326)