The study - Developmental Neurotoxicity Study of Dietary Bisphenol A in Sprague-Dawley Rats, by Donald G. Stump et al – said the chemical did not act as a developmental neurotoxicant to the rodents as measured in guidelines laid out by the OECD and the US Environmental Protection Agency (EPA).
Steve Hentges, of the American Chemistry Council, M Sue Marty of the Dow Chemical Company and Anne Chappelle of Sunoco Inc were also listed as co-contributors.
No evidence of harm
The authors said: “The results of this guideline-based study are expected to be useful for human health risk assessment as these endpoints are generally recognized as relevant to neurodevelopment in humans.”
The paper, which appeared in the online journal Toxicological Sciences, detailed how the researchers exposed female rats and their offspring to oral doses of the chemical ranging from 0.15 to 2,250 ppm daily during gestation and lactation. The animals were monitored in a number of ways to determine the potential of BPA to “induce functional and/or morphological effects to the nervous system”. These included detailed clinical observations, auditory startle, motor activity and learning and memory evaluations using the Briel water maze.
The Sprague-Dawley species of rats were used as subjects because they have been shown to have been “responsive to BPA exposure” in other studies.
The team, headed by Stump of WIL Research Laboratories, Ohio, concluded there was no evidence of either treatment related neurobehavioural ill-effects, or of neuropathology or effects on brain morphometry.
Based on body weight reductions of the rats, the study said the no-observed-adverse effect level (NOAEL) for systemic toxicity was 75 ppm (5.85 mg/kg/day and 13.1 mg/kg/day during gestation and lactation, respectively). It added there was “no treatment-related effects at lower doses or non-monotonic dose responses observed for any parameter”.
“There was no evidence that BPA is a developmental neurotoxicant in rats and the NOAEL for developmental neurotoxicity was 2250 ppm, the highest dose tested (164 mg/kg/day and 410 mg/kg/day during gestation and lactation, respectively),” said Stump.
BPA essential
Jasmin Bird of PlasticsEurope stated: “This new study adds to the weight of scientific evidence that consumers need not be concerned when using products made from materials based on Bisphenol A.”
The body said plastics containing BPA were “essential components in keeping packaged beverages, food and preserves safe from spoilage and contamination”.
The group added that regulatory agencies worldwide had backed the use of the chemical. While no agency outside Canada has banned its use, the US Food and Drug Administration (FDA) and the French Food Safety Agency (AFSSA) have both expressed concerns about the continued use of BPA and called for more research into its effects on humans. The European Food Safety Authority (EFSA) has also convened an international summit on the substance to take place in the spring.
BPA is used in the manufacture of polycarbonate bottles and the epoxy food linings of cans.