Why not just swap bisphenol A (BPA) with an alternative? The canning industry gets that question often — especially when BPA makes the headlines. To understand why they stick with it, it helps to understand the BPA facts.
A Russian chemist first discovered BPA, a carbon-based synthetic compound, in 1891. Nothing much was done with the chemical until the 1950s, when scientists invented polycarbonate resin, a combination of BPA and phosgene COCl2. Polycarbonate resin is strong, clear and resists breaking or cracking. According to Packaging Digest, “Polycarbonate was initially used for electrical and electronic applications such as distributor and fuse boxes, displays and plug connections and for glazing for greenhouses and public buildings.”
Quickly scientists realized polycarbonate could be used as sturdy food containers, and this proved to be a crucial discovery. Prior to 1950, the case-fatality ratio of the food-borne illness botulism was 60 percent. This was often caused by factory-canned foods, which, when perforated, were susceptible to bacterial growth. Used as an epoxy-resin can coating, BPA became a life changer — and quite literally a life saver. New BPA-based coatings provided an impenetrable barrier between the food and the metal, preventing bacteria from getting into the food. In fact, for more than 38 years, the FDA has not reported a single incidence of food-borne illness as the result of a faulty can.
The BPA facts show that the compound protects food from contamination and therefore decay, leading to a longer shelf life for epoxy-resin-lined cans — two years or more. This has greatly improved the quality of nutrition for consumers buying food on a budget. It means better resilience in natural disasters. And it’s important for shipping foods, such as to the military or to overseas charities.
Concerns about BPA’s use in packaging began to form in 1997, when a researcher from the University of Missouri-Columbia published a paper demonstrating increased prostate weights in mice exposed to BPA. Although that research could not be replicated by more powerful studies, a significant health scare followed, as more and more research found adverse effects resulting from BPA.
Much of that research used nonstandardized tests that were difficult to interpret with relation to human health. After years of significant media coverage of negative health effects from BPA, Canada declared BPA toxic in 2008 and revoked its approval for use in baby bottles; the European Union followed in 2010 with a similar restriction. Several U.S. states began to implement bans on the use of BPA in baby bottles, and some expanded the ban to include infant formula packaging. The metal packaging industry was able to respond to the required changes for infant formula packaging because infant formula and baby foods are, by nature, non-acidic, so their interaction with the can coating is far less than other foods’. In fact, infant formula and baby foods are some of the easiest foods to pack in metal packaging, and while not as well tested, alternative coatings that were sufficiently protective were available for these food products.
The issue continued to gain steam, with more than $180 million in research funds directed toward BPA by the U.S. National Institute of Environmental Health Sciences. In 2010 the FDA aligned itself with the National Institutes of Health and expressed “some concern” about BPA. Around this time the FDA, through its National Center for Toxicological Research (NCTR), began research on BPA, using techniques that shed more light on BPA’s effects on humans, and at doses relevant to the amounts of BPA people are exposed too. NCTR’s work painted a different picture of BPA.
Through large, multigenerational studies, the FDA showed that, at doses relevant to human exposure, there were no effects from oral exposure to BPA. Similarly, in 2011, researchers at the Pacific Northwest National Laboratory (PNNL) published research looking at how humans effectively inactivate BPA and quickly eliminate it from the body. In fact, this research showed that the active form of BPA could not be measured in human participants who were exposed to high levels of it, using the best techniques from both the FDA and the Centers for Disease Control and Prevention. The PNNL group continued their research and in 2015 published a paper further studying human subjects exposed to well over 1,000 times the amount of BPA that humans are typically exposed to. That research showed that the level of the active form of BPA in humans was too low to cause harm.
This recent work has helped global regulatory agencies determine that current uses of BPA in food packaging are not a risk to consumers. In December 2014 the FDA published its most recent safety assessment on BPA, which it described as “safe.” In January 2015 the European Food Safety Authority released a comprehensive risk assessment on BPA, finding that current exposures present “no health risk from oral exposure” for “all ages (including all infant and toddler groups).”
And what about Canada, the country that started the debate? Recent assessments from the government body Health Canada have said that “current dietary exposure to BPA through food packaging uses is not expected to pose a health risk to the general population, including newborns and young children.”
When concerns have arisen over the years, some consumers have wondered: Why not switch to an alternative? But it’s just not that easy to find as universally safe and effective a product. In order to invent and test new liners, it would take several years to ensure the safety, quality, nutritional value and flavor of the food. Although this issue has been disputed for over 20 years, there are two BPA facts that are not in dispute: Metal cans using BPA-based liners have provided decades of safe food to consumers; and the FDA, EFSA and Health Canada state that the current use of this material is “safe.”