BPA is disrupts hormones and has been linked to cancer and infertility. From the paper receipts you get from stores to paper money, the BPA can easily transfer through the skin. Usually we worry about BPA in plastic baby or water bottles and canned food linings. "receipts
By Janet Raloff
Web edition : Wednesday, October 7th, 2009
What's the charge?Some but not all cash-register and credit-card receipts can be rich sources of exposure to BPA, a hormone-mimicking pollutant. Christopher Baker while working at Polaroid Corp. For more than a decade, John C. Warner learned about the chemistry behind some carbonless copy papers (now used for most credit card receipts) and the thermal imaging papers that are spit out by most modern cash registers. Both relied on bisphenol-A. Manufacturers would coat a powdery layer of this BPA onto one side of a piece of paper together with an invisible ink, he says. "Later, when you applied pressure or heat, they would merge together and you'd get color. "
At the time, back in the '90s, he thought little about the technology other than it was clever. But when BPA exploded into the news, about a decade ago, Warner began to develop some doubts. Research was demonstrating that this estrogen-mimicking chemical was leaching out of polycarbonate plastics, out of the resins used to line most food cans and out of dental sealants. In the womb, this chemical could disrupt the normal development of a rodent's gonads — or evoke changes that predisposed animals to later develop cancer. Warner recalls that these reports piqued his curiosity about whether the color-changing papers that were increasingly proliferating throughout urban commerce still used BPA. By this time, the organic chemist was teaching green chemistry at the University of Massachusetts. "So I'd send my students out to local stores to get their cash register receipts. " Back in the lab, they'd dissolve the paper, run it through a mass spectrometer and look for a telltale spike in the readout that signaled the presence of BPA. And they'd find it, Warner says. Not in every receipt. But in plenty. And the paper used in the receipts that contained BPA looked no different than papers that didn't. But that was then, before he co-founded the Warner Babcock Institute for Green Chemistry, an organization that works with industry to develop safer products and production processes. So earlier this week I asked Warner whether he had evidence BPA might still be present in those papers. Yep. He turned up BPA-based receipts in use the last time he looked. Which was last month. And the amount receipts carry isn't trivial. "When people talk about polycarbonate bottles, they talk about nanogram quantities of BPA [leaching out, " Warner observes. "The average cash register receipt that's out there and uses the BPA technology will have 60 to 100 milligrams of free BPA. " By free, he explains, it's not bound into a polymer, like the BPA in polycarbonates. It's just the individual molecules loose and ready for uptake. "... "At least pregnant women would know to wash their hands after picking up a BPA-laced receipt. And we'd all know to keep such paper out of hands of kids. We might also want to store those receipts in some zip-it-closed plastic baggie, not our wallets. " -- By Janet Raloff
Dollar bills and receipts tainted with Bisphenol A, report finds
Concerned about your BPA: Check your receipts