They began production/release of their BPA-free lids in January 2013. To identify a BPA-free box (they are not marking it on their boxes, according to the company spokesman), look for a production code printed/stamped on each box that is One Letter Followed by 10-11 Numbers. On Ball boxes, you’ll find the code next to the flag on the bottom of the box. On Kerr boxes, you’ll find the code on the back of the box, above the text. It won’t be a particular code, but only BPA-free boxes will have these (or any) codes like this stamped on them.
I quickly checked my stash of canning lids, and was able to compare an older box (above, left) with one purchased in March 2013 (above, right).
A glance at the top panel of these two similar-looking boxes (above) shows that only the newer one has a code. After making an inquiry, Ball confirmed the news:
BPA free lids began to roll out last Fall. Those products will have production date codes stamped on the outside of the package. Starting this summer, you will find the “BPA Free” message start to appear on the front face of those packages.
Until these new labeled boxes come out, check for the numbered code next to the flag to ensure that the lids you’re buying are BPA-free.
Above: Older lids with a whiter lining to the left; new BPA-free lids with a darker lining and more prominent, slightly tweaked “button” to the right. When asked, the spokesperson for Ball was unable to tell me what the new lining is made of, only that the information is “proprietary.” Still, we’re glad to finally have a BPA-free choice.
Update 6.6.13: A response from Jarden Home Brands: “The coating does not contain BPS and is not enamel based.”
Update 7.19.13: See More on Identifying Ball’s BPA-Free Lids for additional tips.