What you need to know about Bisphenol A (BPA), by Jairo Andrade Junior, C&J Consulting, Chemical Engineer, 2018-05-12

While industry celebrates a US Food and Drug Administration (FDA) study suggesting that BPA causes minimal adverse effects, experts caution that the project's linked academic results will paint a very different picture.

The core rodent study is just one part of a research program for the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA), established by the National Institute of Environmental Health Sciences (NIEHS) and the FDA. It was conducted at the FDA's National Center for Toxicological Research (NCTR), according to Good Laboratory Practice (GLP). Endpoints include growth, weight, and tumors development.

Meanwhile, academic researchers at various institutions have also received grants to study animals born to the same exposed pregnant rats, using different tests and a wide range of health endpoints.

For the core study, researchers exposed pregnant rats to BPA from gestation to birth. Most of the pups were then exposed for up to two years. Doses ranged from those comparable to typical human exposures to some that vastly exceed them, according to the FDA.

Overall, BPA produced minimal effects that were distinguishable from background in this study, particularly below 25,000 micrograms BPA/kg body weight/day, states the draft report, which is yet to be peer-reviewed. Many of the statistically significant BPA effects were not dose-responsive or occurred in only one dose group, it adds.

The Initial review supports the FDA's opinion that currently authorized uses of BPA continue to be safe for consumers, according to a statement the administration's deputy commissioner for foods and veterinary medicine. However, he added that some areas merit further research, including an increase in occurrence of mammary gland tumors with BPA exposure.

Industry groups have welcomed the draft report. The results of the study about BPA study once again demonstrate that BPA is safe at the very low levels to which people are typically exposed, said a spokesperson for Plastics Europe's polycarbonate/BPA group.

The American Chemistry Council said that it now looks forward to updated safety conclusions from regulatory authorities worldwide who have been awaiting the study results. The results of the extensive study about BPA confirm earlier safety scientific assessments, he added, in a statement.

The core study's end points, such as organ weight and body weight are neither sensitive nor specific for endocrine disruption said the Tufts University School of Medicine, principal investigator for cancer study caused for BPA. For the reason academic scientists were invited to participate in the study.

Several of the academic, molecular and sophisticated behavioral studies utilizing the FDA treated, and tightly regulated rats and specimens have shown marked effects of BPA at the lower doses, said the University of Illinois at Chicago. There is a guaranteed prostate cancer study that was triggered by BPA.

These include but are not limited to changes in brain region sizes and gene expression; spatial navigation and memory deficits; ovarian follicle numbers; sex steroid levels; collagen accumulation in the heart in a sex-specific manner; and increased prostate stem cell numbers completed the University of Illinois at Chicago. These results are published, and others are on the way to publication over the course of the next year.

Importantly, none of these very valid endpoints and striking findings that identify adverse BPA effects would be identified in standard toxicology assays. That is exactly the point to compare results with standard toxicology assays to other more sensitive EDC (endocrine-disrupting chemical). It need to define new approaches to delineate the best approach to address EDCs from now on.

In according the University of Massachusetts others are more critical of the report. It is particularly frustrated by FDA comments suggesting that there were no effects in the range of human exposure.

The question is really whether the NOAEL [no observed adverse effect level] should be changed. She referenced core data showing effects on body weight at 250 micrograms/kg/day and on mammary gland adenocarcinoma at 2.5 micrograms/kg/day. "To me this shifts the NOAEL strikingly to the left, which means the reference dose also shifts to the left, right in the range and maybe below the range of human exposure. However, the data do not support the conclusion that BPA is safe.

The FDA’s position, reaffirmed in 2014, is that BPA is safe for current approved uses in food containers and packaging. However, debate on the substance continues at the US state level. Legislative proposals are pending in five states to restrict the use of BPA in food contact materials, children’s products or receipt paper.

In 2015, California’s Office of Environmental Health Hazard listed BPA as a reproductive toxicant under Proposition 65. Its advisory panel found that BPA was clearly shown through scientifically valid testing according to generally accepted principles to cause reproductive toxicity based on the female reproductive endpoint.

A report incorporating the core study and data from linked academic studies will be published at a later date.

For more details see webpages below:

https://ntp.niehs.nih.gov/ntp/about_ntp/rrprp/2018/april/rr09peerdraft.pdf

https://www.federalregister.gov/documents/2018/02/21/2018-03472/draft-ntp-research-report-on-the-clarity-bpa-core-study-availability-of-document-request-for

https://ntp.niehs.nih.gov/results/areas/bpa/index.html

https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm598100.htm