BPA – is it toxic? An up-to-date summary of the facts

Back in 2008, Bisphenol A, a chemical that is commonly used as an additive in plastic, made headlines as a silent killer. When studies linking BPA to health risks hit the 24 hour news cycle, people panicked, the phone lines at doctors’ offices were rushed and stores immediately started to sell out of BPA-free bottles and sippy cups. However, many people were left wondering if this hysteria was founded in truth or if it was merely another instance of daytime news shows sensationalizing unproven “facts” in order to bolster their ratings.

BPA background 
In order to understand the risks associated with BPA, it’s first important to know what it is and how it is used. BPA is an industrial chemical that has been used as a plastic softener since the 1960s. It is most commonly found in polycarbonate plastics and epoxy resins, and is frequently used in food and beverage containers like water bottles, as well as many other consumer goods. Epoxy resins are often used to coat the inside of metal products that come in contact with foods. Most food cans, bottle caps and water supply lines are lined with epoxy resins. So if this chemical is used in so many products, how could it possibly be as dangerous as some people would have us believe?

Much of the fear surrounding BPA stems from some research that demonstrated that the additive can seep into food or beverages from containers that are made with BPA. These studies also indicated that exposure to BPA can cause negative health effects on the brain, behavior and prostate glands of fetuses, infants and very young children. These studies represent valid concerns, and the resultant reactions on the part of the public is hardly surprising. However, like so many of the outcomes of controversial health risk research, you have to understand the whole picture before you come to a conclusion.

Studies and analysis
According to the U.S. Food and Drug Administration, there is some cause for concern when exposing children to BPA. Research conducted by the FDA’s National Center for Toxicological Research discovered that in rodent studies, active BPA could pass from expectant mothers to their unborn offspring following oral exposure – however, the concentrations of BPA transferred between mother and offspring were so low that they could not be accurately measured. The research also found that oral administration of BPA resulted in rapid metabolism of the chemical to an inactive form, which means that swallowing the chemical yielded significantly lower internal exposure of BPA than would exposure from injection. Furthermore, the FDA found that humans and other primates of all ages actually metabolize and excrete BPA much more quickly and efficiently than do rodents.

“In order to understand the risks associated with BPA, it’s first important to know what it is and how it is used.”

In a separate study that addressed the ability for BPA to seep from food containers into food used what is referred to as migration testing to see if the chemical could enter food and beverages. Migration testing is a relatively straightforward test that is based on the ancient, Archimedean principle of displacement. Essentially, these tests measure the weight and volume of a food substance and a food container. The food is then placed in the container and left alone for various lengths of time under different circumstances. The food is then removed from the container and the same measurements are taken. If there are any discrepancies between the two points of measurement, then it is clear that some kind of material migration has occurred. In its research, the FDA discovered that the migration of BPA between containers and food was negligible.

Regulatory overhaul
Still, the regulatory body has taken several measures to overhaul the BPA industry. For example, the FDA has recently partnered with Health Canada to encourage the food container industry to refine their manufacturing methods in an effort to minimize BPA migration in infant formula packaging. Additionally, as of July 2012, the FDA took action to disallow the use of BPA in baby bottles and “sippy” cups. A year later, in 2013, the agency banned the use of BPA based epoxy resins in the coatings of infant formula packaging. It is worth noting, however, that the FDA is only interested in controlling BPA exposure to infants and young children – that’s because normal BPA exposure in adults appears to be relatively innocuous.

The nipples on some baby bottles used to contain BPA - not anymore.
The nipples on some baby bottles used to contain BPA – not anymore.

Risk associated with age and level of exposure
As citizens of an industrialized society, people are exposed to toxic chemicals on a daily basis. Carcinogens and other dangerous chemicals are everywhere, but the human body is an amazing machine that can tolerate minor to moderate levels of many chemicals that are technically toxic or harmful in large doses. In order to confirm this sentiment in regard to BPA, FDA experts specializing in toxicology, analytical chemistry, endocrinology, epidemiology and other fields completed a four-year review of more than 300 scientific studies. This review discovered absolutely no information that would indicate that low exposure to BPA would be hazardous for adults.

At the end of the day, it’s important to recognize that high exposure to any chemical is likely to be toxic to some degree. Moreover, it’s generally prudent to acknowledge the fragility of fetuses, infants and young children. As such, it’s advisable to limit their exposure to chemicals that may pose a risk, such as BPA. With any potentially dangerous chemical, however, it is useful for researchers to continue to study and monitor BPA and its effects on both humans and non-human clinical test subjects.

Breaking news: EFSA weighs in on BPA
One day after this original article was finalized, the European Food Safety Authority issued a press release on the toxicity of bisphenol A. The report was not directly linked to any new studies – instead, it contained the findings of a EFSA panel of experts who had recently finished reviewing existing research. Interestingly, the regulatory body concluded that BPA poses no health risk to consumers of any age group including unborn children, infants and adolescents at normal exposure levels.

However, it’s important to note that this report was issued after the EFSA issued a new tolerable daily intake of BPA, which significantly reduced the amount of BPA exposure that the EFSA considers “safe.” Previously, BPA’s TDI was 50 micrograms per kilogram of body weight per day – the latest report was published after the regulatory agency reduced the TDI to a mere 4 micrograms per kilogram of body weight per day .

Essentially, this means that normal exposure to BPA that falls within the acceptable TDI range should have no averse affect on human beings. Nonetheless, there are several unknown factors which still need to be addressed, such alternative forms of exposure such as skin absorption and direct exposure to blood and the rest of the circulatory system. Although this new report is encouraging for BPA safety, additional testing will be required to determine the safety of other methods of exposure.

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