If there’s one thing you probably touch every day, over and over again, it’s cash register receipts. Quick—check your wallet, your pocket, or the bottom of your purse: There they are.

Now researchers have found that those innocent-seeming pieces of paper contain high levels of bisphenol A, the same chemical recently banned from plastic water bottles because of the serious long-term health risks it poses.

According to a study published this week in the journal PLOS ONE, people's blood levels of BPA spiked after they touched cash receipts—particularly if they had lotion, sanitizer, or another skin care product on their hands.

“BPA has been proven to cause reproductive defects in fetuses, infants, children, and adults as well as cancer, metabolic, and immune problems in rodents,” said study author Frederick vom Saal, a professor of biology at the University of Missouri.

”Our research found BPA levels from receipts much higher than exposures from food packaging or plastic,” added vom Saal. “And BPA from thermal papers will be absorbed into your blood rapidly. At those levels, many diseases such as diabetes and disorders such as obesity increase as well.”

A report issued by the United States Environmental Protection Agency in January found that 94 percent of receipts contain BPA.

A hormone disruptor that mimics and interferes with estrogen and testosterone, BPA is used as a heat-activated ink developer in the production of thermal receipts, such as those dispensed from cash registers, gas pumps, and ATMs. The process is even used to print airline tickets. Because the BPA sits on the surface of slick, plastic-coated paper, it absorbs easily into the skin, the study found.

Our devotion to lotion isn’t helping. Sunscreen, hand sanitizers, and other personal care products contain chemicals that help pierce the skin ("dermal penetration enhancers," to use industry-speak). Think about how often you use hand products and how often you touch food immediately after touching a receipt, and it's easy to see how they provide BPA a direct route into the body.

Related Paper Waste Is Being Turned Into a Safer BPA Alternative

Consider these scenarios, all of which were observed by the researchers in a study conducted in restaurants and food courts in a Columbia, Missouri, shopping mall. In one, you pay for your food and receive a receipt, which you touch before taking your food. In a second scenario, common in many fast-food restaurants, there is a dispenser of hand sanitizer on the counter, which you use before taking the receipt and your food. In a third scenario, common in take-out restaurants, the receipt is stapled to the folded top of the bag, right where your hand rests as you carry it.

All three scenarios provide a direct route for BPA into your fingertips.

Sure enough, when the researchers tested blood levels of BPA after study participants cleaned their hands with sanitizer, then held receipts, they found an immediate spike in BPA levels. Add the third step of eating greasy food (in this case, french fries), and BPA levels soared.

It’s not the first study to find large amounts of BPA in thermal receipts; a 2010 study published in Green Chemistry Letters and Reviews found high levels of BPA in the surface coating of thermal paper. But vom Saal and his team were the first to go a significant step further, taking blood samples and measuring BPA blood levels after research subjects had touched receipt paper.

So how do we avoid touching BPA-tainted receipts?

There's no simple solution, vom Saal said. "Virtually all store receipts, ATM receipts, etc., are thermal paper, and no safe chemical-free alternative exists, making it difficult for manufacturers to reformulate the ink used in receipts."

Sure enough, the EPA study on BPA in receipts concluded that no safer alternative to the chemical exists.

So how to protect yourself?