Paper receipts also seen as source of BPA exposure
July 27, 2010 By LYNDSEY LAYTON. The Washington Post
WASHINGTON – As lawmakers and health experts wrestle over whether a controversial chemical, bisphenol-A, should be banned from food and beverage containers, a new analysis by an environmental group suggests Americans are being exposed to BPA through another, surprising route: paper receipts. The Environmental Working Group found BPA on 40 percent of the receipts it collected from supermarkets, automated teller machines, gas stations and chain stores. In some cases, the total amount of BPA on the receipt was 1,000 times the amount found in the epoxy lining of a can of food, another controversial use of the chemical. Sonya Lunder, a senior analyst with the environmental group, says BPA's prevalence on receipts could help explain why the chemical can be detected in the urine of an estimated 93 percent of Americans, according to the Centers for Disease Control and Prevention. Full article here
Concerned about BPA: Check your receipts
By Janet Raloff, Wednesday, October 7th, 2009
Some — but not all — cash-register and credit-card receipts can be rich sources of exposure to BPA, a hormone-mimicking pollutant.
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.