In 2008, Congress banned the use in children's toys and child care articles of several chemicals known to disrupt normal development and reproduction of mice and rats. The legislation was a response to accumulating scientific evidence supporting the hypothesis that exposure to certain chemicals in consumer products and the environment might be adversely affecting human reproduction, growth, development or metabolism by interfering with endocrine systems. This book summarizes the science underlying the environmental endocrine-disruptor hypothesis and describes congressional actions and related programs and policy issues at the EPA.