Researchers at Granada University say that till receipts which fade after a time are printed with ink which could cause cancer.  The thermal paper used to produce the receipts contains bisphenol A (BPA), often simply called bisphenol, which has been under investigation by some countries for ten years.

Professor Nicolás Olea said last month that consumers should avoid storing such receipts in purses, wallets or cars after studies showed that BPA can lead to hormone-dependent cancers.  It has been linked to infertility, autism, ADHD, obesity, type two diabetes, premature births and the early onset of puberty.

An international team, led by researchers in Granada, analysed 112 thermal paper receipts and tickets from Brazil, Spain and France.  Professor Olea said the paper is easily recognisable because it turns black if held near a heat source.

The group’s findings showed that 90 per cent of the receipts collected in Brazil and Spain tested positive for BPA.  However, this was true for only half of the receipts from France where the government has taken action to reduce the use of that chemical compound in thermal paper since 2014.

Previous research shows that cashiers and waiting staff who routinely handle up to 30 such receipt an hour have significantly higher levels of the chemical in their blood and urine than the average.  The Granada researchers suggested people should “reject” paper receipts until public health measures are taken, but noted that the Spanish government has undertaken to remove BPA from its receipts by 2020.