New BPA-Free Mason Jar Lids: Are They Really Safer?

I can see from the WordPress statistics on this blog that a lot of people are searching for information about bisphenol-A (BPA) in mason jar lids. Apparently word is getting around that Ball and Kerr lids are now BPA-free. The rumor is true: According to Jarden Home Brands, the manufacturer of both Ball and Kerr products, lids produced since last fall have no BPA. Starting this summer, boxes of the lids will be labeled “BPA-free.”

As you might expect, Jarden isn’t saying what chemical or chemicals have taken the place of BPA in the new lids. There are some fifteen other bisphenols, each of them labeled with a different letter or two. At least one, bisphenol-S (BPS), has been thought a safe substitute for BPA. A report published in Environmental Health Perspectives in March of this year found otherwise. BPS, the authors concluded, “disrupts membrane-initiated E2-induced cell signaling, leading to altered cell proliferation, cell death, and PRL release.” E2 is the estrogen estradiol. PRL is prolactin. In other words, BPS messes with your hormones.

Other bisphenols may be at least as dangerous. A report published in the same journal in 2011 concluded, “Almost all commercially available plastic products we sampled—independent of the type of resin, product, or retail source—leached chemicals having reliably detectable EA [estrogenic activity], including those advertised as BPA free. In some cases, BPA-free products released chemicals having more EA than did BPA-containing products.”

Until we have further evidence to the contrary, we can assume that plastic-coated jar lids contain dangerous chemicals, and we should limit contact between the lids and the food we put in jars. Though we can’t keep delivery people from turning packages of gift jars upside down, at home we can take care to keep our jars upright, in the pantry and in the refrigerator.

For more information about BPA and ways to avoid it in home canning, see my article “Home Canning, BPA-Free.”


19 thoughts on “New BPA-Free Mason Jar Lids: Are They Really Safer?”

  1. Thanks for setting this straight just in time for canning season! It also seems to me that the new “BPA-free” lids is just replacing one chemical with another. Keeping jars upright at home to avoid contact with the coating is an easy thing to do. – I have tried Weck jars as an alternative. They are pretty but much more expensive because they are mostly only available by mail order, and they are a pain to use, even Weck tells you to check the seal a few times, something you do not have to worry about with the band-and-lid system.

  2. Last year I tried the Tattler BPA free reusable lids. I was concerned that they are just another type of plastic. I liked the reusable concept but to be honest, I am a very experienced canner and I had poor seals with many of the lids. This year I went back to my old familiar Kerr and Ball lids. I will look for the new ones and I give them credit for at least trying. And remember if you can your own food, especially tomato products, you are definitely exposing your food to less BPA than commercially canned products with liners. I did do a little bit of research on this topic and wrote a blog post on it myself at this link

    1. Thanks for the link and the reminder of the benefit of canning in glass. Even if you stored your mason jars topped with plastic-lined lids upside-down, you would subject yourself to much less chemical contamination than you would by buying food tin cans.

    2. @Burgesonfamilyfarm: I had never thought of that aspect neither! I just read your post, which made me check all the containers I use for liquids, plus the freezer bags, for BPA, phew. – This is such an interesting string, and certainly another reason to get more people grow and can their own food.

  3. this might be a strange question but I heard that if storing food in BPA lids that turning them upside down will avoid the problem. This will not work when canning, however. I also heard that putting a piece of wax paper inside your lid will also help prevent exposure to the BPA – would this work?

    1. The waxed paper might prevent exposure to BPA, but I’m afraid that it might also interfere with venting or sealing or both. Any Ball or Kerr lids you buy now should be BPA-free, so experiments with waxed paper probably aren’t worth the trouble. If you’re still using lids with BPA, the easiest solution is to keep the jars upright. Any contact of the food with the lid during processing will be very brief.

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