Give us this day our daily foam expander. It may sound odd, but in America, your loaf of bread can contain ingredients with industrial applications – additives that also appear in things like yoga mats, pesticides, hair straighteners, explosives and petroleum products.

Some of these chemicals, used as optional whiteners, dough conditioners and rising agents, may be harmful to human health. Potassium bromate, a potent oxidizer that helps bread rise, has been linked to kidney and thyroid cancers in rodents. Azodicarbonamide (ACA), a chemical that forms bubbles in foams and plastics like vinyl, is used to bleach and leaven dough – but when baked, it, too, has been linked to cancer in lab animals.