The shop receipt you just put in your pocket
Most bills from card machines are printed on thermal paper coated with BPA or a close cousin. Your skin picks it up, and hand sanitiser makes it worse.

Next time the chemist or the petrol pump hands you a bill, scratch it with a fingernail. If it leaves a dark line, it is thermal paper. There is no ink on it. The paper is coated with a chemical that darkens with heat, and for years that chemical has been bisphenol A (BPA), or its replacement, bisphenol S (BPS).
BPA acts a little like oestrogen inside the body. Studies have linked it to hormone disruption, which is why many countries took it out of baby bottles, and why the European Union banned it in till receipts from 2020.
What surprised researchers was how easily it moves. In a 2014 study from the University of Missouri, people who used hand sanitiser and then held a receipt for just a few seconds had BPA in their blood soon afterwards. Sanitiser, hand cream and oily fingers all help it through the skin. So does the very normal habit of holding the bill in one hand while eating the samosa you just paid for with the other.
What to do instead - Say "no bill, thanks", or ask for it on SMS, email or the UPI app. Most shops offer this now. - Don't let children play with receipts or the paper rolls from billing machines. - Keep bills in a separate pocket of your wallet, not loose with food or tiffin boxes. - Wash your hands with soap and water after handling a stack of bills. Sanitiser is the wrong tool here. - If you handle bills all day, at a till, a pharmacy counter or a fuel station, wash your hands often or wear gloves.
One receipt will not harm you. It is daily, repeated contact that adds up, and that is easy to cut down.

