There are different types of approaches. Some U.S. environmental laws come out of governmental committee concerned with public health, e.g. Clean Air Act. On the other hand, the Toxic Substance Control Act attempts to balance the benefit of new chemicals to society versus their potential for adverse health consequences. This Act comes out of the Commerce Committee not out of the Public Health Committee.

http://www.epa.gov/compliance/civil/federal/caa.html

Toxic Substance Control Act

http://www.epa.gov/compliance/civil/federal/tsca.html