Session 3: Exposure data sources

Data sources for prioritizing human exposure to chemicals
Kathie Dionisio, US EPA

Kathie Dionisio, S.M., Sc.D.


Human Exposure & Atmospheric Sciences Division
National Exposure Research Laboratory
US EPA Office of Research and Development


Humans may be exposed to thousands of chemicals through contact in the workplace, home, and via air, water, food, and soil. A major challenge is estimating chemical exposures, which requires understanding potential exposure pathways directly related to how chemicals are used.

With ~80,000 chemicals currently registered under the U.S. Toxic Substances Control Act and only a small subset having been well characterized, there is a need to develop methods to obtain high-throughput exposure estimates so that chemical hazard screening approaches and exposure estimates together can allow for the complete development of high-throughput risk models.

While information on production volume of chemicals is currently available, a large, uniformly organized repository of information on how chemicals are used, product composition, and other properties (e.g. physicochemical form of the chemical within the product, or physical form of the product) currently does not exist.

The Chemical/Products Categories Database (CPCat) is the result of a large-scale effort to catalog and consolidate relatively disparate data sources in order to make chemical use information publicly available, and in a form useful for high-throughput exposure modeling.

Although this work was reviewed by the EPA and approved for publication, it may not necessarily reflect official Agency policy. EPA does not endorse the purchase of any commercial products or services mentioned in this publication.