Bisphenol A (or BPA) is now on Canada’s most dangerous substances list, making this country the first jurisdiction in the world to declare the plastic-making compound toxic. BPA has become a health concern because it is able to mimic estrogen, leading to concern that it could cause cancers and other illnesses linked to having excessive amounts of the female hormone. Experiments with animals have found it to be biologically active, many using exposures in the range to which humans are subject to. According to federal reviews, nearly all Canadians are exposed to trace amounts of the chemical. BPA is believed to be ingested through residues leaching from polycarbonate plastic containers and tin cans, which use the compound on their inside liners.