The Integrated Risk Information System (IRIS) is a program of which U.S. federal agency?

• A. National Exposure Research Laboratory
• B. Centers for Disease Control and Prevention
• C. National Oceanic and Atmospheric Administration
• D. Environmental Protection Agency

Answer: (D)

IRIS centers on providing toxicity information used in human health risk assessment. This program is maintained by the Environmental Protection Agency, which uses the data to derive reference doses for noncarcinogenic effects and cancer slope factors for carcinogenic risk. Those health-valued benchmarks help EPA set exposure guidelines and inform regulatory decisions, and other federal or state agencies may rely on IRIS data when evaluating environmental risks. While agencies like CDC or NOAA may use IRIS information, the program itself is an EPA responsibility.