BPA is a hormone-disrupting chemical found in some plastics. Chronic exposure may increase the risk for breast cancer, infertility, thyroid disease, PCOS, insulin resistance, and heart disease. Several countries around the world have banned BPA, and many Australians have taken steps to reduce their exposure.
Most BPA exposure comes from food that has been stored in plastic-lined tins (tinned tomatoes are the worst), but EFTPOS receipts or thermal paper receipts are a source of substantial exposure.
Thermal receipt are up to 3% BPA by weight. Holding them with a dry hand transfers BPA onto the skin. Wet or greasy hands pick up 10x more. After 2 hours, the BPA is completely absorbed into the blood stream, and cannot be washed off. Alcohol (from hand wipes, for example) increases the rate of absorption.