When Did BPA Stop Being Toxic?
BY STEVE HENTGES | MARCH 1ST 2018 04:55 AM

If you’ve ever heard of the chemical bisphenol A (BPA), and who hasn’t, youprobably have the distinct impression that it’s highly toxic. After a steady
drumbeat of more than 15 years suggesting that BPA is linked to virtually every
health effect known to man, how could you think any differently?
There are literally thousands of studies on BPA in the scientific literature, many ofwhich report biological effects of one sort or another. But separate from the sheervolume of data, what the data mean is the key question. The consensus ofgovernment bodies worldwide, based on their independent evaluations of the data,
has been that BPA is safe for use. Nevertheless the conventional wisdom is theopposite: that BPA is dangerous.
In light of that conventional wisdom, you might be puzzled by recent headlines
such as “BPA unlikely to be harmful, federal study shows” and “Plastic Additive BPA
Not Much Of A Threat, Government Study Finds.” Clearly there is some sort of adisconnect between the recent headlines and the conventional wisdom.
Unless you’ve been paying very close attention to the scientific literature, youprobably didn’t know that U.S. government scientists have been conducting an indepth research program on BPA for more than 10 years. This multi-million dollar
sustained effort was aimed at resolving any remaining uncertainties about thesafety of BPA.
What led to these headlines is that the U.S. National Toxicology Program (NTP) justreleased the findings of the capstone study of that research program. Known as
the CLARITY Core study, it’s the largest study ever conducted on BPA. The study
successfully resolved uncertainties as intended and the results indicate that BPA
has very little potential to cause health effects even when people are exposed to itthroughout their lives.
As stated in the conclusion of the study report, “BPA produced minimal effects thatwere distinguishable from background.” In a statement released in conjunction
with the report, Dr. Steven Ostroff, Deputy Commissioner for Foods and Veterinary
Medicine at the U.S. Food and Drug Administration (FDA) noted: “our initial review

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supports our determination that currently authorized uses of BPA continue to besafe for consumers.”
What’s All the Controversy Been About?
It’s been known for many decades that BPA is weakly estrogenic. By itself that
biological property doesn’t mean much and it didn’t attract much interest until
about 20 years ago. From that point forward scientists worldwide have beenfascinated by BPA and have conducted thousands of studies of every typeimaginable. Of particular interest is the potential for BPA to cause health effects at
low levels of exposure, for example even in the very low dose range of typicalconsumer exposure.
The conclusions of scientific assessments by government bodies worldwide
consistently support the safety of BPA. The most straightforward conclusion is theone from FDA, which is summarized with their Q&A: “Is BPA safe? Yes.” To
address residual controversy, FDA worked in conjunction with other U.S. federal
government agencies to design a research program that would resolve any
remaining uncertainties.
How the U.S. Government Set Out to Resolve the Controversy
To comprehensively understand the safety of BPA, several complementary types ofscientific data are necessary. In particular, we need to understand levels ofexposure, what happens to BPA when it enters the body, and the potential for
actual exposures to cause health effects.
To fill the first need, the U.S. Centers for Disease Control and Prevention (CDC) has
conducted biennial biomonitoring studies of the U.S. population since 2003 tomonitor consumer exposure to BPA (and many other substances). From thesestudies we know that human exposure to BPA is quite low, typically below 0.1
micrograms BPA/kilogram bodyweight/day.
From a comprehensive set of pharmacokinetic studies conducted by FDA and NTP
scientists on rodents, non-human primates and human volunteers, we know thatBPA is quickly eliminated from the body after exposure. Even more importantly, as
BPA is absorbed into the body after oral exposure it is efficiently converted into a2/4

metabolite, which is the biologically inactive form of BPA that actually enters thebody and is then quickly eliminated in urine.

Based on the pharmacokinetic and exposure data, we can predict that BPA is
unlikely to cause health effects at typical consumer exposure levels. The results ofthe CLARITY Core study, which was conducted by FDA senior scientists in FDA’s
research laboratory, resoundingly confirm that prediction.
The scope and magnitude of the CLARITY Core study are unprecedented, but size
alone is not what makes the results so compelling. The laboratory animals in theCLARITY Core study were exposed to BPA from pregnancy, through early-life
development, and continuing through their entire lifetime. The exposure levels
ranged from very low to an upper level that is more than 250,000 higher thantypical consumer exposure levels.
Exposure occurred during all developmental stages of life, which are likely to be themost sensitive life stages. Potential health effects were monitored throughout theanimals’ lifetimes, which ensured that any delayed effects from early-life exposure
would be found.
Because of this comprehensive and rigorous study design, FDA can confidently
reaffirm their perspective that “currently authorized uses of BPA continue to be safe
for consumers.” The perspective of FDA is fully supported by solid scientificevidence, just as it should be.
What’s Next?
The study will next undergo peer-review by a panel of experts selected byNTP. That will actually be the second peer-review since the pathology results havealready been peer-reviewed through an earlier NTP process known as a Pathology

3/4Working Group. Comments from that process have already been addressed in thereport that was recently released.
The upcoming peer-review process includes a public meeting scheduled for April 26,
after which the NTP draft report will be released in final form with responses to anypeer-review comments. The study will also be published in the scientific literature,
which will add a third layer of peer-review as part of the normal publication
process.
Without a doubt, the results of the CLARITY Core study will be of high interest to
government bodies worldwide that have assessed the safety of BPA. Similar to theperspective of FDA, we can anticipate that other government bodies will also relyon the CLARITY Core study finding to conclude, again, that BPA is safe.
So going back to the top, when exactly did BPA stop being toxic? Based on thecollective results from the CLARITY Core study and the in-depth U.S. government
research program, that’s a trick question. It never was toxic.

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