Have you ever wondered why store receipts feel ever-so-slightly powdery? That’s because most receipts are printed on “thermal” paper, which changes color when heated. A thin coating of powder helps develop the dyes. That powder, it turns out, contains an endocrine-disrupting chemical, and we’re absorbing it through the skin on our fingers.
A study published Tuesday in the journal JAMA found that people who continuously handle store receipts wind up with significantly elevated levels of bisphenol-A, more commonly known as BPA, in their urine.
BPA has been used since the 1960s to line soup cans, and to make a wide array of plastic bottles and food containers. The chemical mimics human estrogen in the body, and can “disrupt” the body’s hormone, or endocrine, system, though what doses are considered harmful is a matter of debate. Studies link BPA to breast cancer, diabetes, and obesity, as well as hormone abnormalities in children. One study found that more than 90 percent of Americans have some level of it in their urine.
Whereas BPA in things like cans and bottles are “bounded,” or attached to other molecules that must break down for a person to absorb the chemical, the BPA in receipts is present in loose powder, which easily leaves a very high concentration of the chemical on peoples’ fingers. Dr. Shelley Ehrlich of Cincinnati Children's Hospital Medical Center wanted to know how much of that actually ends up in our bodies.
The new study looked at BPA in participants’ urine levels before and after two hours of continuously handling receipts. Initially, all participants handled the receipts without wearing gloves. After a washout period of at least a week, about half of the participants handled receipts again, but this time they wore gloves.
Two hours after touching the receipts without gloves, the BPA levels in the participants' urine was significantly elevated, rising from 1.8 micrograms of BPA per liter to 5.8 micrograms per liter.
After 8 hours, the study authors tested some of the gloveless participants again, and found that the BPA levels went up to 11.1 micrograms per liter, an almost five-fold increase.
Though the BPA levels, even when elevated, represented “relatively low doses,” (canned soup, for example, can contain much-higher doses of 22 micrograms per liter of BPA), Ehrlich tells Newsweek she feels “the general public should be aware of this” overlooked route of exposure to the chemical.
“It is not something people have to get extremely alarmed about. But this finding might be of concern to those who handle receipts continuously, like bank tellers and store cashiers,” she says.
Study participants who wore gloves had no significant increase of BPA in their urine, confirming that the route of exposure was through the skin, not from breathing in the powder.
“I’m a precautionary person, so I would say that women who are pregnant, of childbearing age, adolescents, other [vulnerable] people like that, they could consider some kind of protective gloves. Anything that acts as a barrier should be good.”
Though Ehrlich and her team’s study is the first to conclude that receipts raised concentrations of BPA in urine, others have expressed concern about receipts and BPA.
A 2012 University of Missouri-Columbia report warned that the FDA’s estimates for safe exposure to BPA is based on oral ingestion only, and Dr. Frederick Vom Saal, an author on the report, told the Huffington Post last year that that around 50 percent of all thermal paper used to print store receipts is coated with BPA.
The FDA’s “safe” exposure limits assume that food and beverage packaging is the only source of exposure to BPA, the report says, leaving them inadequate to mediate other routes of BPA exposure. Regardless, Vom Saal and his colleagues write, endocrine disruptors aren’t safe at any level.
“For endocrine-disrupting chemicals there are no threshold doses below which exposures are safe, a reality that regulators are unwilling to acknowledge.”
For Ehrlich, the problem lies with the American approach to chemical regulation.
Since 2007 Europe has taken a precautionary approach by compelling companies to prove that their chemicals are safe, while in the U.S., the burden of safety verification lies with the Environmental Protection Agency. Facing a tight deadline to test the chemicals, the overwhelming majority end up on the market without testing. The EPA has only tested and published data on approximately 200 of the 83,000 chemicals in its inventory, according to a California Senate review from 2010.
In 2010, the EPA listed BPA as a “chemical of concern.” The agency says a notice of “proposed rulemaking” on BPA is currently pending review by the Office of Management and Budget.
“Things just need to be tested before they’re released. We’re kind of working backwards, trying to see what could be a problem after it is already out there,” Ehrlich says. “It would be nice to do it the other way around.”