Perspective | Published:


Endocrine disruptors and the future of toxicology testing — lessons from CLARITY–BPA


Five years ago, an ambitious collaboration, the Consortium Linking Academic and Regulatory Insights on Toxicity of BPA (CLARITY–BPA; henceforth CLARITY), was launched by three US agencies. The goal was to provide a definitive evaluation of bisphenol A (BPA) and explain disparities between traditional regulatory studies and findings from independent investigators. BPA or vehicle-treated rats from an FDA facility were used in a guideline study and animals and/or tissues were provided to academic researchers for analysis. An interim summary released in February 2018 by the FDA concluded that currently authorized uses of BPA continue to be safe. We disagree. In this Perspectives, we summarize the goals, design and problems of CLARITY. We conclude that, despite its flaws, CLARITY provides important insight and, taken together, the data provide compelling evidence that low-dose BPA exposure induces marked adverse effects. Indeed, the greatest number of effects were observed at doses 20,000 times lower than the current ‘safe’ dose of BPA for humans.

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The authors gratefully acknowledge C. Lawson for assistance with figures and tables. The authors are supported by the NIH National Institute of Environmental Health Sciences grants K22ES025811 (L.N.V.), R56 ES013527 (P.A.H.) and RO1 ES023254 and R56 ES020662 (A.C.G.). The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The funders played no role in the writing of the report or in the decision to submit the article for publication.

Author information

The authors contributed equally to all aspects of the article.

Competing interests

L.N.V., P.A.H. and A.C.G. have received travel reimbursement from universities, governments, non-governmental organizations and industry to speak about endocrine-disrupting chemicals.

Correspondence to Andrea C. Gore.

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Fig. 1: The CLARITY study.
Fig. 2: Summary of CLARITY results for the five BPA doses: guideline study.
Fig. 3: Summary of CLARITY results for two ethinyl estradiol and five BPA treatment groups: academic studies.