BPA Is Everywhere, Except Where It’s Not
BY STEVE HENTGES | SEPTEMBER 6TH 2016 09:24 AM

With the high level of attention to bisphenol A (BPA) over the years, it’s easy to get
the impression that BPA is everywhere and we’re constantly being exposed to highand harmful levels in our daily lives. You might even have seen BPA referred to as
an “everywhere chemical.”Adding to the confusion, the media is notorious for attaching pictures of productsthat contain absolutely no BPA to articles about BPA. Perhaps the most common
examples are pictures of bottled water. Single-serve bottles containing water,
sports drinks or carbonated beverages are almost universally made from a plastic
known as polyethylene terephthalate (PET), which has no connection to BPA at all.
Perhaps stimulated by the controversy and confusion, scientists have been
conducting studies to look for BPA in various places and measure how much BPA
we’re actually exposed to. It may be a surprise to some, but many of these studies
show that BPA is not present everywhere, exposure levels are very low, and, mostimportantly, those levels are not harmful.
How Is Exposure to BPA Measured?
An entire field of science, known as exposure science, is dedicated to studying
exposure of people to chemicals that occur in their environment. Several types ofstudies from this large and growing field are particularly informative to understandhuman exposure to BPA. These studies measure how much BPA goes in the body,how much comes out and, most importantly, what happens in between.
What Goes In? These studies measure BPA in products or places that people
contact, and estimate how much of that BPA could enter the body. Although
exposure may only be estimated and not directly measured, these studies canevaluate specific sources of exposure. Several studies published this year focusedon potential exposure to BPA from sources either known or suspected of containing
BPA.
Dental sealants. Many sealants are based on a derivative of BPA known
commonly as bis-GMA (bisphenol A glycidyl methacrylate). Because bis-1/4

GMA could contain ultra-trace levels of residual BPA, the American Dental
Association analyzed 12 dental sealants from the U.S. market to determine
how much BPA could be released. As reported in ADA’s Professional
Product Review, the median amount of BPA released was 0.09 nanogramsfrom the amount of sealant applied to four teeth. That vanishingly small
amount led ADA to conclude, as summarized in the headline to its news
release, “BPA in dental sealants safe.”
Hair care products. For some time, concerns have been raised thathairdressers may be exposed to unsafe levels of various chemicals fromhair care products they use in the salon. To address these concerns, theFinnish Institute of Occupational Health and the National Institute for
Health and Welfare conducted a study to measure exposure to BPA (andseveral other chemicals). As reported: “According to the results,hairdressers in Finland are not exposed to … bisphenol A … any more than
the rest of the population.” The result is important not only for
hairdressers but also for consumers. If hairdressers, applying hair careproducts throughout their workdays are not exposed to BPA, it seems
highly likely that consumers using the same products on their own hairwould also not be exposed to BPA.
Food products. It’s well-known that BPA-based epoxy resins arecommonly used as protective coatings on food and beverage cans to help
protect the contents from contamination. The Food Safety Authority ofIreland (FSAI) conducted a Total Diet Study to measure levels of BPA (andother chemicals) in 147 foods and beverages representative of the normal
Irish diet. Not surprisingly, trace levels of BPA were found in 30% of thesamples analyzed. Exposure to BPA was then estimated based on foodconsumption data. Comparison of estimated exposure to the stringent
health-based guidance value for BPA in Europe led FSAI to conclude that
“exposure to BPA is of low concern.”

The studies listed above, along with many earlier studies, confirm that BPA is not
literally “everywhere.” Where it is present, the levels are very low and estimatedexposures are well within health-based guidance values for safety.

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What Comes Out? Since BPA is quickly eliminated from the body through urine
after exposure, analysis of BPA in urine provides a good measure of total exposure
to BPA from all sources combined. Recent studies have focused on exposure toBPA in the potentially sensitive subpopulations of reproductive-aged women andreproductively active couples.
Reproductive-aged couples. A study conducted by researchers at theUniversity of Utah measured BPA in repeated urine samples from couples
planning pregnancy. The median BPA level (2.4 microgram BPA/L urine)
was comparable to levels reported in large-scale studies conducted by theU.S. Centers for Disease Control and Prevention (CDC) that are
representative of the U.S. population.
Reproductive-aged women. A similar study from the U.S. National
Institutes of Health and a team of researchers in the U.S. and France
measured BPA in repeated urine samples collected from reproductive-agedwomen. The median BPA level (2.8 micrograms BPA/L urine) in this study
was also comparable to levels measured in the U.S. population.

A separate series of studies conducted by CDC (known as the National Health andNutrition Examination Survey, or NHANES) indicate that typical exposure to BPA inthe U.S. population is less than 50 nanograms BPA/kg bodyweight. This level ismore than 1,000 times below safe intake levels set by U.S. government agenciesbased on extensive scientific review. The two new studies indicate that exposure
to reproductive-aged women and reproductively active couples are also well withinthese safe limits.
What’s Inside the Body? In contrast to the studies above, which measure BPA
outside the body, these studies measure how much BPA is actually in thebloodstream where it could potentially cause harm. The studies are morechallenging to conduct, but are of high value for evaluating whether exposure toBPA is harmful. Two recent studies examined levels of BPA in the blood of apotentially sensitive subpopulation and a potentially more highly exposed group.
Pregnant women. A study jointly conducted by researchers at the PacificNorthwest National Laboratory and the U.S. Food and Drug Administration

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(FDA) measured BPA levels in urine and blood from a group of pregnant
women. Low levels of BPA were found in urine, indicating exposure similar
to levels found in the studies above. More importantly though, no BPA wasdetected in blood for most of the samples with a very sensitive analyticalmethod. In cases where BPA was detected, clear evidence was found thatthe trace levels near the detection limit were the result of contaminationand not indicative of actual exposure.
Cashiers. A minor use of BPA is as a component of the heat-sensitive
coating on some thermal receipt papers. Since cashiers handle receipt
paper throughout the day in the course of their work, a U.S. National
Toxicology Program study measured BPA levels in urine and blood from agroup of cashiers before and after their work shifts. Although low levels ofBPA were detected in urine, no BPA was detected in most of the blood
samples. Similar to the study above, sample contamination was suspectedin most of the sample where trace levels of BPA were detected.

These studies are particularly informative in that they demonstrate thatmeasureable levels of BPA are not present in blood, even when low-level exposure
to BPA is confirmed by measurement of BPA in urine. This seeming contradiction isdue to the efficient metabolism and clearance of BPA from the body that has
been demonstrated in numerous studies on laboratory animals and humanvolunteers. Any BPA to which we are exposed is converted to a biologically inactive
metabolite that is quickly eliminated from the body in urine. As a result, thepotential for BPA to be harmful at typical exposure levels is virtually eliminated.
BPA Is Safe Where It Is, But It’s Not Everywhere
Although no single study can answer all of our questions on BPA, results from thesestudies taken together provide powerful evidence to evaluate the safety ofBPA. These new results strongly support the conclusions of government bodies
worldwide that have reviewed the extensive science on BPA. A representativeexample is FDA, which answers the question “Is BPA safe?” with an unambiguous
answer – “Yes.”

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