Description: The IRIS Program is located within EPA’s National Center for Environmental Assessment (NCEA) in the Office of Research and Development (ORD). EPA’s IRIS Program identifies and characterizes the health hazards of chemicals found in the environment. Each IRIS assessment can cover a chemical, a group of related chemicals, or a complex mixture. IRIS assessments provide the following toxicity values for health effects resulting from chronic exposure to chemical: Reference Concentration (RfC), Reference Dose (RfD), Cancer descriptors, Oral slope factors (OSF) and Inhalation unit risk (IUR).

    Number of Chemicals: 603