The U.S. Environment Protection Agency (EPA) defines hazardous chemicals as any substance or material that requires a Material Safety Data Sheet under Occupational Safety and Health Administration Act’s hazardous communication standard.  A Material Safety Data Sheet provides both workers and emergency personnel with proper procedures for handling or working with a particular substance.  The Occupational Safety and Health Administration Act assures safe and healthful working conditions for working men and women by authorizing enforcement of the standards developed under the Act.

Manufacture, processing, and use of chemicals result in its environmental release.  The EPA has developed information summaries on selected chemicals to describe ways o avoid exposures to these chemicals and the effects of exposure.  It has also listed hundreds of chemicals as hazardous chemicals which in one way or another is a threat to the environment.

Many toxic chemicals are being currently being released into the air and water of the U.S.  Such chemicals pose a major but little studied threat to the health of Americans, especially development and learning ability of children. The EPA is committed to reducing the environmental release of chemicals through source reduction and other practices that reduce creation of pollutants.  Source reduction is decreasing the amount of chemicals used during manufacturing or distribution of products and packages.  Source reduction is the top priority practices of the EPA.