Appendix B 



Integrated Risk Information System (IRIS) 



Overview of IRIS 



The Integrated Risk Information System (IRIS), prepared and main- 

 tained by the U.S. Environmental Protection Agency (EPA), is an 

 electronic data base containing health risk and EPA regulatory infor- 

 mation on specific chemicals. IRIS was developed for EPA staff in 

 response to a growing demand for consistent risk information on 

 chemical substances for use in decision-making and regulatory ac- 

 tivities. Although IRIS is designed for EPA staff, it is also accessible 

 to state and local environmental health agencies. IRIS is available to 

 libraries, private citizens, and other organizations by means of DIAL- 

 COM, Inc.'s Electronic Mail telecommunications system. The infor- 

 mation in IRIS is intended for EPA staff without extensive training in 

 toxicology, but with some knowledge of health sciences. 



The heart of the IRIS system is its collection of computer files covering 

 individual chemicals. These chemical files contain descriptive and 

 quantitative information in the following categories: 



• Oral and inhalation reference doses (RfDs) for chronic non- 

 carcinogenic health effects 



• Oral and inhalation slope factors and unit risks for chronic 

 exposures to carcinogens 



• Drinking water health advisories from EPA's Office of Drink- 

 ing water 



• EPA regulatory action summaries 



• Supplementary data on acute health hazards and physi- 

 cal/chemical properties 



