The new chemicals process at the Environmental Protection Agency (EPA): structure-activity relationships for hazard identification and risk assessment.

Section 5 of the Toxic Substances Control Act (TSCA) does not require any toxicity testing as a prerequisite for submission of a Premanufacturing Notice (PMN) for a new chemical. In order to compensate for the lack of actual test data, a process involving structure-activity relationships (SAR) for assessing hazard potential was constructed. The hazard assessment is then coupled with an estimation of potential exposure to determine potential risk. This process involves the use of multiple interdisciplinary teams that work within a 90-day time frame to complete approximately 2000 risk assessments per year.