Bisphenol A Free Bottles, BPA-Free Pacifiers, BPA-Free Receipts
I previously poo-pooed the threat of the estrogen mimetic bisphenol A (BPA) from polycarbonate bottles, cans and pacifiers, because my quick calculations indicated that there was just too little BPA and too many other natural sources of estrogens that haven’t been problems. But it’s not the water that’s the problem, it’s the other plastic, your credit card.
Some Receipts Are Covered with BPAIn a
recent article on the use of BPA for thermal printing it was claimed that some receipts have as much as 100 milligrams of BPA. I simply didn’t believe this, because 100mg is 0.1 gram, which is what I approximate as the weight of a cash register receipt. So, I emailed the investigator and he clarified. He encountered some coupons that were printed on 100 sqare inches of thermal printer paper. That is one whopping receipt, but even at that size, the coating with BPA was impressive and scary.
Thermal Printing Heats BPA with Second Reagent to Make PigmentsThermal printing ink, e.g. BPA plus an acid-sensitive dye, smeared over the whole surface of the special thermal paper. Heating the paper in the printer head causes the BPA, which is a weak acid, to release its protons and react with the dye to produce a colored pigment. In order to make the printing visible, a lot of initially colorless ink has to be coated on the paper. That means that perhaps 5% of the weight of the thermal printer paper is BPA and that BPA is all on the surface and able to rub off onto your hands!
Don’t Touch the ReceiptsA recent
study of BPA exposure during gestation and subsequent stereotypical sex-specific behavior showed that women with higher BPA in their urine during their first trimester of pregnancy gave birth to babies that developed with less than their expected sex-specific behaviors. In other words, higher BPA in utero meant that boys behaved more like girls and vice versa. Most of the women tested had about 1 ppm BPA contaminating their urine. Some had a thousand fold more. Even if they ate polycarbonate bottles, they could not have had more than 1,000 ppm (1 ppm = one part per million = 1 microgram per gram = 1 milligram per liter, so 1,000 ppm = 1 gram per liter). This suggests that the women with funny, really average kids, were getting their BPA from some other source than bottles and cans contaminated with BPA.
Wash Your Hands or Wear Gloves When ShoppingI think that the culprit is the cashier. Why are some of these people so cheerful when they have to deal with so many louts in line? Maybe it is the BPA soaking into their finger tips from the BPA-soaked receipts that they are handing to you. You may have wondered why some people become fanatical about coupons. Maybe they are also taking in too much BPA. What about the kids playing with credit card receipts? BPA has been linked with precocious sexual development. Maybe it would be safer to let the kids play with cigarette butts.
Not All Receipts Have BPAI have asked a few cashiers if their receipts are printed on thermal paper laced with BPA, but most don’t know or care. Many receipts are printed with ink, so they aren’t a problem. Either way, the cashier should know to avoid self-contamination or risks to customers. May you should ask the next time you hand over the plastic.