Tuesday, May 22, 2018
We know from authoritative sources that BPA is safe. For example, the U.S. Food and Drug Administration (FDA) asks and answers the question on its website: “Is BPA safe? Yes.” And the U.S. is not alone; many other government authorities around the world say something similar about the safety of BPA.
Those bottom line conclusions on safety may be all we want or need to know. But inquiring minds might also wonder how we know that BPA is safe, not just who said so? In particular, what scientific data supports those conclusions?
A very important type of data comes from the field of exposure science. If we want to know if just about anything is safe, we need to know how much of it we’re exposed to. After all, we could be harmed by overdosing on just about anything. The basic scientific principle commonly stated as “the dose makes the poison” has been known for centuries.
Fortunately, we know quite a bit about how much BPA we’re exposed to and where it comes from. A good example was reported recently by the Dutch National Institute for Public Health and the Environment (RIVM) in a report titled “Dietary sources of exposure to bisphenol A in the Netherlands.”
From previous analyses, we know that our primary source of exposure to BPA is from our diet. One reason is that many food and beverage cans contain an epoxy resin-based protective coating to prevent corrosion of the metal can and contamination of the contents. Exposure can occur if trace levels of residual BPA in the coating migrate into a food or beverage.
What the RIVM scientists did is calculate BPA exposure from measured levels of BPA in various foods and Dutch food consumption patterns. Full details of how they did this for young children (ages 2-6 years), older children and adults (ages 7-69 years), and women of childbearing age (18-45 years) are provided in the RIVM report.
Consistent with exposure estimates in other countries, the calculated exposures for the Dutch population are quite low. The RIVM scientists then concluded with their interpretation of what these exposure levels mean: “The exposure estimates indicate that possible health effects of BPA exposure via food are negligible.”
All exposure estimates were well below the safe intake level for BPA set by the European Food Safety Authority (EFSA), as well as applicable standards in the U.S. and elsewhere in the world. The RIVM scientists further noted that “the conservative choices made to address the uncertainties have very likely resulted in an overestimation of the exposure.” That’s an important point that increases confidence in the overall safety conclusion.
The EFSA safe intake level for BPA was established in 2015 after a thorough review of available scientific data on BPA. What wasn’t available at the time were the results of the CLARITY Core Study, which was conducted by senior FDA scientists to resolve any remaining uncertainties about the safety of BPA.
The results of that study, which is of unprecedented size and scope for BPA, were recently released by the U.S. National Toxicology Program, which provided funding for the study. As stated in the conclusion of the draft study report, “BPA produced minimal effects that were distinguishable from background.” Overall, the results indicate that BPA has very little potential to cause health effects even when people are exposed to it throughout their lives.
Although EFSA has not yet incorporated the CLARITY study findings into its safety assessment, FDA has already started to do so. In a statement released in conjunction with the report, Dr. Stephen Ostroff, Deputy Commissioner for Foods and Veterinary Medicine at the U.S. Food and Drug Administration (FDA) noted: “our initial review supports our determination that currently authorized uses of BPA continue to be safe for consumers.”
With the results of the CLARITY Core study now available, the Dutch are wise to listen to the science on BPA.