1. Integrated Risk Information System; U.S. Environmental Protection Agency: Washington, DC, 2001. Available at: http://www.epa.gov/iris/ index.html.
2. Clean Air Act Amendments of 1990; 42 U.S C. 7412 (b)(3)(B).
3. Clean Air Act Amendments of 1990; 42 U.S.C. 7412 (b)(1).
4. Modifications to the 112(b)1 Hazardous Air Pollutants; U.S. Environmental Protection Agency, U.S. Government Printing Office:Washing-ton, DC, 2001. Available at: http://www.epa.gov/ttn/atw/atwsmod.html.
5. National Research Council. Science and Judgment in Risk Assessment; National Academy Press: New York, 1994.