US EPA

The Inhalation Exposure-Response Analysis Methodology Document is expected to provide guidance on the development of the basic toxicological foundations for deriving reference values for human health effects, focusing on the hazard identification and dose-response aspects of the NAS Risk Assessment Paradigm. The document is likely to change over time to incorporate new developments in toxicology and risk assessment and new policy guidance of the Agency. To allow for the timely incorporation of new developments, the methodology should be viewed as a framework and not as stringent procedural requirements. The vision for the preliminary methodology is that it will be revised and additions made as more illustrative example assessments are undertaken; this document does not comprise the entirety of this methodology. The iterative process of example assessments guiding methods and vice versa will culminate in a final methodology that is useful over a wide array of situations, and for use by many Program Office within EPA, as well as outside the Agency.

This methodology document is intended to be a useful and useable guide through the specifics of developing an inhalation reference value. A stepwise approach including case studies is being utilized in the effort to develop this methodology. Supplements to this document will follow to address issues not covered herein.

U.S. EPA. Inhalation Exposure-Response Methodology. U.S. Environmental Protection Agency, Washington, DC.