Editor's Note: This morning, CPR President Rena Steinzor will testify at a House hearing regarding EPA's Integrated Risk Information System chemical database (full testimony). This post by NRDC Senior Attorney Daniel Rosenberg, cross-posted from Switchboard, explains the importance of IRIS and how the program is under attack.

Thursday morning, the House Science Committee’s Investigation and Oversight Committee will hold a hearing on EPA’s premier program for assessing the dangers of chemicals.   It is called the IRIS program, (which stands for Integrated Risk Information System).  The IRIS program looks at the science available on the potential dangers of a chemical and determines what hazard that chemical may pose – such as causing cancer, birth defects, diseases, etc., and what level of exposure, if any, is likely to be without an appreciable risk of harm.  The IRIS program doesn’t issue regulations; it is focused on assessment of chemical hazards.  But other parts of EPA, such as the air program and the water program, rely upon the IRIS assessments in setting their health standards to protect people from toxic chemicals.  Other states and countries also rely upon the IRIS assessments. 

Because of the importance of IRIS assessments for determining …