Perchlorate is the explosive component of solid rocket fuel, fireworks, road flares, and other products. Used heavily by the Department of Defense (DOD) and related industries, perchlorate also occurs naturally and is present in some organic fertilizer. This soluble, persistent compound has been detected in drinking water supplies, milk and many foods. Because of this widespread occurrence, concern over the potential health risks of perchlorate exposure has increased, Members of Congress have urged the Environmental Protection Agency (EPA) to set a federal drinking water standard for this chemical. This book reviews perchlorate contamination issues and related developments.