The main purpose of this legislation, known as the "No IRIS Act of 2025," is to prevent the Environmental Protection Agency (EPA) from using certain assessments produced by its Integrated Risk Information System (IRIS) when making rules or regulations. The goal is to limit the influence of these specific assessments in the EPA's regulatory processes. The key provisions of the act state that the EPA Administrator is prohibited from using IRIS assessments as a basis for developing or finalizing any rules or regulations. This includes any regulatory, enforcement, or permitting actions.