Ban Hormone-bending Thermal Paper, Say Scientists

Using hand sanitizer, then touching thermal paper and eating will cause your body's concentration of BPA, an endocrine disruptor, to spike.

Tijmen Stam, Wikimedia Commons

Thermal paper is everywhere, and now it turns out that handling it – especially after using hand sanitizers - increases our exposure to Bisphenol A, an acknowledged toxin that disrupts our hormonal systems. In fact thermal paper is so unsafe that the scientists behind a new study, published this week in PLOS ONE, think its use should be abolished altogether.

Think touching thermal paper and eating, let alone after sanitizing one's hands, is a rare problem? Not so. The scientists tested relevance and found that 50 million  Americans eat fast food each year. Some fast-food restaurants even helpfully offer customers a spray of sanitizer right before handing over the thermal-paper credit-card receipt. Receipt "contact time" is anywhere from about 12 seconds to a minute, and hand sanitizers are now a $200 million-a-year industry just in the U.S.

Thermal paper is coated with a chemical that reacts to heat, and is commonly used for example in receipts and fax machines. If you give your credit card to a store and it gives you a slip of shiny paper to sign – that’s thermal paper. In Israel, so are receipts on buses and taxis and so is most receipts you get at stores.

Like thermal paper, bisphenol A, or BPA, is also everywhere, though since studies began revealing the damage it can do to people (and animals), some manufacturers have begun scaling back its use.

The chemical is found in hard plastics, epoxy resins used in food and beverage packaging, dental fillings, sportswear and much more. As well as in the thermal paper spit out by cash machines, gas pumps, taxis, your local grocery, and just about everybody taking cash or a credit card from you. BPA is gradually being eliminated from baby bottles after scientists have realized the damage the chemical can do as it leaches out of the material and seeps into the body.

As an endocrine disruptor, BPA disrupts our normal hormonal metabolism and the jury’s out on what “safe” levels might be, if any. Meanwhile, a study by the U.S. Center for Disease Control showed that in America at least, the chemical appears in the urine of 95 percent of adults and 93 percent of children. That counts as “everybody.”

As the University of Missouri team points out in the Plos One report, this indicates widespread exposure to the substance from multiple sources. And while food manufacturers have been scaling back its use, the group of scientists found that BPA is being lavishly applied to the outer layer of thermal paper as a print developer. BPS, a commonly used alternative development chemical, is no safer, the team warns; nor are any of the 19 substitutes tested.

This is a problem chiefly for people who use hand sanitizers (gels and foams used instead of soap), the group explains, because these substances contain chemicals that increase the penetration of certain other chemicals into our skin, by as much as 100-fold. The chemicals whose absorption they enhance include BPA.

“We found that when men and women held thermal receipt paper immediately after using a hand sanitizer with penetration-enhancing chemicals, significant free BPA was transferred to their hands and then to French fries that were eaten,” the scientists write.

Oh, and by the way, BPA is getting into recycled paper from tossed-out thermal paper. Now you know.

Nor is the potential damage theoretical: “The elevated levels of BPA that we observed due to holding thermal paper after using a product containing dermal penetration-enhancing chemicals have been related to an increased risk for a wide range of developmental abnormalities as well as diseases in adults,” the team reports.

Their conclusion: Eliminate the use of thermal paper, since no safe ways have been found to produce it. And meanwhile? Don’t rub the receipt, don’t kiss or lick it, and don’t eat it for heaven’s sake. And if you must use hand sanitizers, consider that they’re increasing the absorbent properties of fatty chemicals like BPA.