When it’s 7pm and you haven’t thought about dinner yet, heating up a can of chunky stew or throwing a can of beans into a cheesy burrito sounds like the best idea ever. By now, you’ve probably heard about BPA in canned foods, but many cans now say “BPA-free” on them. Hurray for that, right?! Every can still needs a thin liner inside so that the food doesn’t corrode the metal from the inside out. So if they are not made with BPA, what are these new liners made of? And does it mean that canned foods are safer to eat now?

What is BPA?

BPA, or bisphenol A, is a chemical that is often used in plastics to make them clear and strong. It is also in epoxy resins that can line water pipes and food cans, and is used in receipt paper (1). Although BPA is the most well-known bisphenol, there are dozens of other bisphenols (often called BPA replacements) out there that are chemically similar to BPA.

BPA is one of the better known endocrine disrupting chemicals (EDCs). These chemicals look like and act like hormones in the body, which confuse the endocrine system and cause disruption of its normal functions. Since the endocrine system is responsible for metabolism, growth and development, reproduction, and so much more, scientists are finding out more every day about the harmful health effects of EDCs.

BPA in Canned food

Canned food has been around for a long time and since the 1960’s, a thin epoxy lining made with the chemical BPA has been used to protect the inside of the can from corroding. Corroding metal is not good, so a liner is definitely needed in order for canned food to have a good shelf life.

There were two problems though. First, more and more studies piled up showing the harmful endocrine disrupting effects of BPA (2). Secondly, many studies showed that BPA moves from the can lining into the food that is eaten, and that things like acidity, heat, and fat affected how much BPA ended up being in the food (3,4). As a result, there was more and more pressure to remove BPA from can linings.

In fact, reports have shown that there has been a decline in can linings with BPA. The Center for Environmental Health found a huge decline from 2017 to 2019 in canned foods that had BPA linings. In 2019, their tests showed that about 95% of cans tested free of BPA. In fact, the Can Manufactuer’s Institute reports that their industry statistics indicate that more than 95% of all U.S. food can production has transitioned out of BPA to alternative liners (5).

New Canned Food Linings

It’s clear that canned food has largely moved away from BPA, but what are they using in new can linings? That part is less clear. The new linings are made from either acrylic, polyester, non-BPA epoxies, polyvinyl chloride (PVC) copolymers, or olefin polymers. Which one depends on the manufacturer. A 2016 report by several nonprofit groups Buyer Beware: Toxic BPA and regrettable substitutes in the linings of canned food notes that many of these new linings are not great alternatives. PVC is not a great substitute because it’s made from vinyl chloride, a known carcinogen. And many of the acrylic linings include polystyrene (hello styrofoam!), which is also a possible human carcinogen. Adequate testing to ensure that these new linings are safe for food have not been done. And it’s probably no surprise that neither PVC or polystyrene are great for the environment!

Even some of the newest liners, like olefin polymers, which are partially derived from plants, have not been completely studied for safety, many times because their formulation is not publicly available.

Moreover, there are only a couple of companies that specify exactly which BPA free liner they have moved to. So, if you see a can with a BPA free symbol on it, you won’t know what they are using instead.

The Bottom Line on BPA in Canned Food

So the bottom line is that yes, canned foods are largely safe from BPA now thanks to the voices of countless consumers and health advocates. But there is more work to be done to ensure that canned foods linings that are used today are safe. Here’s what you can do to best protect your health:

1. Write to companies and ask them what linings they use on their canned food products and ask them to show you safety data.
2. Buy frozen produce and fruits. Food is frozen before it is packaged and frozen food packaging is generally made of safer plastics.
3. Explore canned food alternatives such as glass jars and Tetra-paks.
4. Shop the bulk and dry goods bins and make staples like beans from scratch. Freeze small portions in the freezer for easy accessibility in the future.

References

1. https://www.niehs.nih.gov/health/topics/agents/sya-bpa/index.cfm
2. Rubin, Beverly S. "Bisphenol A: an endocrine disruptor with widespread exposure and multiple effects." The Journal of steroid biochemistry and molecular biology 127.1-2 (2011): 27-34.
3. Sungur, Şana, Muaz Köroğlu, and Abdo Özkan. "Determinatıon of bisphenol a migrating from canned food and beverages in markets." Food chemistry 142 (2014): 87-91.
4. Hartle, Jennifer C., Ana Navas-Acien, and Robert S. Lawrence. "The consumption of canned food and beverages and urinary Bisphenol A concentrations in NHANES 2003–2008." Environmental research 150 (2016): 375-382.
5. https://www.cancentral.com/content/innovations-foo...