A safer refrigerant helped refrigerators become household appliances
Early mechanical refrigerators often used refrigerants that were toxic or flammable. Chlorofluorocarbon refrigerants such as Freon, introduced around 1930, made domestic refrigeration easier to commercialize because they were less immediately hazardous in ordinary use. Decades later, scientists discovered that these chemicals damaged the ozone layer, turning an apparent safety breakthrough into an environmental problem.