This proposed legislation aims to restrict the Environmental Protection Agency's (EPA) use of data from its Integrated Risk Information System (IRIS) program. Specifically, the bill prohibits the EPA Administrator from using any IRIS-generated assessment as a foundational basis for various agency activities. These prohibited uses include developing, finalizing, or issuing any new rule or regulation. Furthermore, the EPA would be barred from utilizing IRIS assessments to carry out any regulatory, enforcement, or permitting actions. The bill also prevents the agency from using IRIS data to inform air toxics assessments or other mapping and screening tools, effectively removing IRIS as a primary data source for these critical functions.