From all of the hysteria that has been generated in recent years — mostly by environmental groups — about trace amounts of the plastic component bisphenol-A (BPA) found in human urine, you might think it was sarin gas rather than a harmless chemical (1) that's been used to line food cans without issue since the 1960s.
Liners are used to seal the can and keep out air. In the absence of liners, food poisoning is more common, so clearly a lot of people have been saved by this technology.
But, if not for chemical scares how would the groups, who raise money based on nonsense, survive? It wouldn't be easy, and so BPA became just one compound in a long line of chemicals that has gotten a "kick me" sign pasted on its molecular back, and scared consumers have been only too happy to fall in line.
BPA became the poster child of the chemical scares industry years ago, but they have since discovered that when you live by bad science, you die by it too.
As I wrote last year, when a number of businesses (including, shockingly, Whole Foods) decided to go "BPA-free," its customers got a little surprise. The surprise is that polycarbonate plastics can be made from any number of "BPs," and all you have to do is choose a different one to trumpet not using BPA. One of those different plastics is made from a related chemical, bisphenol-S (BPS). The primary driver behind this switch was the free market catering to consumer preference, or perhaps more accurately, manufactured consumer preference that was driven by chemophobia, not actual harm.
Though BPA has never been shown to harm anyone, the free market can do what it wants to compete and create more market share. If that leads to higher costs, and therefore lower revenue, due to lower-priced competition that is a risk of doing business. All well and good from an economic sense, except that they are replacing one product never found to be harmful with new things lacking anywhere near the same long-term safety data. That is good for environmental activists — they can raise money to protest BPA, declare victory about the replacement, and then raise more money to get rid of the replacement in a few years — but it's not good for the public.
Because companies went ahead and started moving away from BPA despite any scientific issue, activists began touting their victory while not mentioning that when tested for the ability to mimic estrogen (the vaguely-defined "endocrine disruption"), BPS was shown to be no different than BPA, and was causing arrhythmias in female rats. The relevance of any of this to human health is dubious at best, but that is what makes the activist war on BPA so silly. In 2014, organic chemist Dr. Steve Hentges of the American Chemistry Council published a very nice discussion of this fiasco on Science 2.0.
In actuality, BPA is a very poor estrogen mimic; it binds about 20,000-times less tightly to estrogen receptors than does estradiol itself, which is one reason that it has never caused harm to humans. Contrast that to a favorite product of vegetarians and organic food shoppers — soy — whose primary plant estrogen is genistein. Genistein binds significantly much more tightly to estrogen receptors than does BPA, yet people think nothing about wolfing down large quantities of it. No, that does not make much sense to scientists, either.
So, while replacing one BPx or another BPx is still pretty harmless, if they all go away, the obvious questions are: (1) What will replace them?, and (2) Will it make any difference?
There is a good reason to wonder. Last year, the food giant ConAgra stopped using BPA-based plastics as liners for its cans, and began the switch to acrylic and polyester-based materials. And Campbell's Soup just announced its cans will be BPA-free by mid-2017.
Campbell's has been on a marketing tear. It put labels on its cans saying its products contain genetically modified foods (GMOs) in hopes that anti-science groups would applaud them, and like with ConAgra, the move away from BPA is a marketing response on their part, not a health one.
“We recognize consumer interest in removing BPA from our cans and are pleased to be able to respond to that desire and offer food that our consumers can feel confident in," said Gail Tavill, Vice President, Packaging & Sustainable Productivity at ConAgra.
That "consumer interest" was driven by merchants of doubt, but the public can't be blamed for putting the precautionary principle ahead of science. The thing the public won't know is if the new liners will be better, worse or the same. All they will eventually know is that this new technology cost money to develop, and families will end up spending more to solve a problem that never existed in the first place. Consumers are always penalized for marketing costs.
In Part 2, I will go into more science details on the alternatives to BPA-based plastic liners, such as the science benefits and concerns. It's not as simple as you might think.
(1) The FDA states that BPA is safe at the levels found in food.