Improving Science in Chemical Assessments Act This bill modifies procedures related to specified chemical assessments performed by the Environmental Protection Agency (EPA). Specifically, chemical hazard identification and dose response assessments must be performed by the appropriate EPA program office (they are currently performed by the Integrated Risk Information System program). Additionally, the bill requires the EPA to establish a steering committee to ensure there is no duplication of effort by relevant program offices in conducting covered assessments.

Freedom for Farmers Act of 2023 This bill abolishes the Agency for Toxic Substances and Disease Registry. This agency, which is part of the Department of Health and Human Services (HHS), investigates and responds to environmental exposures to hazardous substances in communities. HHS must transfer authority regarding certain national disease and toxic exposure registries to another appropriate HHS entity.

New Source Review Permitting Improvement Act This bill modifies terminology for purposes of the New Source Review (NSR) permitting program of the Environmental Protection Agency (EPA). In order for a change to a stationary source to be a modification (a change to a stationary source that increases the air pollutant emissions or results in new pollutants) for purposes of the NSR permitting program, the maximum hourly emission rate achievable by such source must be higher than the maximum hourly rate achievable by such source during any hour in the 10-year period preceding the change. A change at a stationary source is not considered to be a modification under the bill if it is designed to (1) reduce the amount of any air pollutant emitted; or (2) restore, maintain, or improve the reliability of operations at, or safety of, the source. However, such changes are not excepted if the EPA determines the increase in the maximum achievable hourly emission rate from such change would cause an adverse effect on human health or the environment. Construction, in connection with a major emitting facility (a type of stationary source), does not include a change at such a facility that does not result in a significant emissions increase or a significant net emissions increase. In relation to major emitting facilities in nonattainment areas, the terms modifications and modified do not include changes at such facilities that do not result in a significant emissions increase or a significant net emissions increase.