2. Relevance to Public Health 2.1 Background and Environmental Exposures to Perchlorates in the United States

Perchlorates are high melting point inorganic salts that are soluble in water. There are five perchlorate salts that are manufactured in substantial amounts: magnesium, potassium, ammonium, sodium, and lithium perchlorate. Perchlorates are powerful oxidizing agents and at elevated temperatures, they can react explosively. The production volume of ammonium perchlorate far outpaces the other salts and it is used primarily as the oxidant for solid rocket boosters as well as some other industrial applications. The solid propellant on U.S. Space Shuttle booster rockets is approximately 70% ammonium perchlorate. The rockets that use perchlorates in defense and aerospace activities are engineered to utilize all of the perchlorate during a successful launch. Perchlorates are also used extensively in electroplating, fireworks, munitions, and other pyrotechnic devices. Perchlorates are also present in fertilizers that were made with Chilean saltpeter.