This is a print on demand edition of a hard to find publication. Perchlorate is both a man-made and naturally occurring chemical used in rocket fuel, explosives, fireworks, and other products. Naturally occurring perchlorate is produced through atmospheric processes and then settles on surface water or land. It can disrupt the uptake of iodide in the thyroid, potentially interfering with thyroid function and negatively affecting fetal and infant brain development and growth. This report examined: (1) what is known about the extent to which perchlorate occurs in the nation's water and food supply and its likely sources; (2) what actions DoD, NASA, and DoE have taken to respond to or lessen perchlorate releases; and (3) what actions states, such as CA and MA, have taken to regulate perchlorate. Charts and tables.