Perchlorate

Ammonium perchlorate is the oxidant in solid rocket fuel. Ignited with aluminum powder, it burns at up to 6,000 degrees Fahrenheit, hurling the space shuttle out of the atmosphere and propelling ballistic missiles across continents. A combination of nitrogen, hydrogen, chlorine and oxygen, ammonium perchlorate is an essential component of military explosives, bottle rockets, fireworks, highway flares, automobile airbags and old-fashioned black powder. Ammonium perchlorate and other perchlorate compounds are also widespread contaminants of drinking water and some foods such as milk and vegetables. In significant amounts, perchlorate disrupts the thyroid’s functioning and may cause thyroid cancer. The U.S. Environmental Protection Agency says drinking water containing less than 24.5 parts per billion of perchlorate poses no hazard to humans, but the Environmental Working Group’s research supports lowering the standard to 1 part per billion. In a 2001 investigation called Rocket Science: Perchlorate and the Toxic Legacy of the Cold War, EWG found that perchlorates had been detected the sources in drinking water for more than 7 million Californians. A 2003 EWG analysis of government data, Rocket Fuel in Drinking Water, determined that perchlorate had been found in drinking water, groundwater or soil in at least 43 states. EWG commissioned independent laboratory tests of lettuce grown in the fall and winter in Southern California or Arizona. Some 18 percent of the lettuce samples contained perchlorates; someone who ate an average serving of these suspect salads would consume 4 times more perchlorates than the level considered safe by the U.S. Environmental Protection Agency. In 2004, EWG-commissioned lab tests of milk sold in Los Angeles and Orange County, CA, supermarkets found that 31 of 32 samples contained perchlorates, some at unsafe levels for infants and children. In October 2007, EWG set up a groundbreaking, interactive National Tap Water Quality database of water contaminants found in 42 states over 2 ½ years. With the database’s launch, for the first time, the public has been able to access information about specific local water supplies across the U.S. In January 2008, an EWG analysis of data from the U.S. Food and Drug Administration (FDA) found that 75 percent of nearly 300 commonly consumed foods and beverages were contaminated with perchlorate. The study found that the average two-year-old would be exposed to more than half of the EPA's safe dose of perchlorate from food; the toddler could reach or exceed the daily limit by consuming more of the chemical in drinking water.