The European Food Safety Authority (EFSA) has lowered the tolerable daily intake levels of bisphenol A (BPA) from 50 µg/kg body weight to 5 µg/kg body weight, pending the outcome of research by the U.S. National Toxicology Program. A publication date for the research is currently unknown. EFSA says that the health risk is low, because the highest estimates for exposure are three to five times lower than the revised limit. EFSA’s experts have concluded that diet is the major source of exposure to BPA, which is also lower than previously estimated.
EFSA reviewed more than 450 studies related to potential health hazards associated with BPA on multiple body systems, including reproductive, nervous, immune and cardiovascular, as well as on the development of cancer.
In a press release posted on its website, the EFSA listed the main findings of its draft opinion on the toxicity of BPA as follows:
- EFSA concludes that exposure to BPA is likely to adversely affect the kidney and liver, as well as causing effects on the mammary gland.
- The opinion additionally considers the possible effects of BPA on the reproductive, nervous, immune, metabolic and cardiovascular systems, as well as in the development of cancer. While an association between BPA and these other effects is not considered likely at present, EFSA concludes they may be of potential concern for human health and they add to the overall uncertainty about the risks of the substance.
- EFSA’s experts recommend that the tolerable daily intake (TDI) for BPA be lowered from its current level of 50 µg/kg bw/ day (or 0.05 mg/kg/bw/day) to 5 µg/kg bw/day (0.005 mg/kg/bw/day) and be set on a temporary basis.
- EFSA says the health risk for all population groups is low — including for fetuses, infants, young children and adults. This is because the highest estimates for combined oral and non-oral exposure to BPA are three to five times lower than the proposed t-TDI, depending on the age group. For all population groups, oral exposure on its own is more than five-fold below the proposed t-TDI.
- The CEF Panel has used a three-step methodology to derive the proposed t-TDI:
- Health hazards that previous scientific studies and reviews have suggested as being associated with BPA exposure were evaluated by applying a weight of evidence approach. These were effects on the reproductive, neurological, metabolic, immune and cardiovascular systems, as well as genotoxic and carcinogenic effects, mammary gland changes and general toxic effects. EFSA concludes there is sufficient evidence to support a likely association between BPA exposure and general toxic effects - specifically effects on the kidney and liver — as well as between BPA exposure and changes in the mammary gland.
- A statistical method known as the benchmark dose approach was used to estimate the level at which BPA causes a small but measurable effect on the kidney, liver and mammary gland in animals. Findings on the kidney in mice were used as a basis for the t-TDI as they were considered to be critical effects occurring reliably at the lowest benchmark dose.
- EFSA also assessed new research results that provide greater insight into the way BPA behaves in the bodies of animals compared to humans. Based on this comparison, EFSA was able to convert the dose level at which BPA causes an effect in mice into an equivalent oral dose for humans. This allowed EFSA to use real data in deriving the t-TDI instead of standard default values — conservative estimates used in the absence of real data — that were used in previous assessments of BPA.
