Experts warned of the presence of chemicals called BPA cause cancer in the paper receipts made of thermal paper, and enter into the material in the manufacture of some types of plastics, which interfere with the work of hormones of the body if released, and their effects to control the secretion and production and function of hormones in the body.

The study by international researchers led by the University of Granada, after analyzing 112 thermal paper receipts and tickets in Brazil, Spain and France, showed that BPA can lead to hormone-dependent cancers, which have been associated with infertility, autism, Type 2 diabetes, premature births and the onset of early puberty.

The writing on the receipts usually disappears after a period of time, so the BPA is added to the receipts to make the writing darker without ink, and in other materials such as plastic water bottles and food bags.

According to Professor Nicholas Olia of the University of Granada, Spain, we can recognize this type of paper because it immediately turns to black if we put it near a source of heat.

He urged that receipts should not be stored in portfolios, clothing pockets or cars.