Toxicity evaluation of bisphenol A administered by gavage to Sprague-Dawley rats from gestation day 6 through postnatal day 90. In this government-funded study, designed and conducted in FDA’s laboratory, FDA researchers characterize the the dose-response relationship between oral exposure to BPA and adverse health effects, where observed, on multiple organ systems at a wide range of doses. This research is particularly important because it comprehensively examines the potential for BPA to cause low-dose health effects of the type previously reported in the scientific literature in small-scale studies.
The Delclos study examines seven (7) low doses of BPA (2.5 – 2,700 µg/kg bw/day), two high doses of BPA (100,000 and 300,000 µg/kg bw day) and two doses of ethinyl estradiol (ethinyl estradiol is a known potent estrogen used to confirm that the test systems were sensitive to estrogenic effects). The dose range covered by the study includes the low doses of BPA where effects have been previously reported in some animal studies, as well as higher doses where effects have been measured in robust, guideline-compliant oral studies.
Results demonstrated that no low dose effects were found for BPA in the wide range of health endpoints examined. According to the study’s authors,
“Our interpretation of the results of the present study is that BPA in the ‘low dose’ region from 2.5 to 2,700 μg/kg bw/day did not produce effects in the evaluated endpoints that differ from normal background biological variation. The experimental model was sufficiently sensitive to detect clear effects of EE2 at both dose levels tested, as well as of the high BPA doses.”
Complementing the Delclos study, research by Churchwell et al provides additional evidence to support the validity of the Delclos findings at low and high doses.