Can shopping make your man impotent?

BPA is used to make the till ink visible on thermal paper. Thermal receipts are similar to rolls of fax paper - they're coated to make them heat-sensitive and slowly fade with time.

The risks come if you handle the receipts and then touch food with unwashed hands or put your hands in your mouth. BPA has been shown to interfere with hormones in your body.

While the researchers looked at male fertility, other scientists have concerns over BPA exposure during pregnancy. So it's a good idea to always wash your hands after handling a thermal till receipt, whether you're planning a baby or are pregnant.

"A substance like that could shift the balance of the sex hormones in men towards oestrogen," says the researcher Professor Frank Sommer. "In the long term this leads to less sexual drive, encourages the belly instead of the muscles to grow and has a bad effect on erection and potency."

BPA is also present in baby bottles - it's the chemical that makes the plastic clear. Most major bottle manufacturers now produce BPA-free bottles, as well as BPA-free sterilisers and dummies.