Perchlorates are the salts derived from perchloric acid (HClO4). They occur both naturally and through manufacturing. They've been used as a medicine for more than 50 years to treat thyroid gland disorders. They're also used as an oxidizer in rocket fuel and explosives and can be found in airbags and fireworks. Both potassium perchlorate (KClO4) and ammonium perchlorate (NH4ClO4) are used extensively within the pyrotechnics industry, and ammonium perchlorate's also a component of solid rocket f… (More on Perchlorate)