Improving Science in Chemical Assessments Act

This bill reorganizes how the EPA conducts chemical assessments for human health risks. It shifts responsibility for these assessments from the IRIS program to specific EPA offices (like Water, Air, and Chemical Safety), requiring them to use new scientific standards that prioritize the weight of evidence, include uncertainty ranges in toxicity values, and document all data transparently. All existing IRIS assessments will transfer to a new EPA database, and a steering committee will prevent duplicate work across offices. The EPA must submit biennial reports to Congress certifying compliance with these new standards.