2 Introduction

The Chemical Exposure Knowledgebase (ChemExpo) is a new, publicly available web-based data search and visualization tool for the exposure domain developed by the Center for Computational Toxicology and Exposure (CCTE) within U.S. EPA’s Office of Research and Development. ChemExpo will surface data managed and curated by the internal-to-U.S. EPA applications and workflows developed to assist with managing, curating, and ensuring the quality of publicly available exposure-relevant data collected by U.S. EPA. These data, which are primarily obtained from documents published by manufacturers, retailers, governments, and NGOs, describe how chemicals are used in commerce, including in consumer products, and are released by EPA as the Chemical and Products database (CPDat) (Dionisio et al. (2018)). CPDat has been previously described in the literature and its data are available in summary form on the EPA CompTox Chemicals Dashboard (the “CompTox Dashboard”). CPDat contains information on chemical use curated from public documents, organized by chemical, Product Use Category (PUC) (Isaacs et al. (2020)), Function Category (FC) (Phillips et al. (2017)), and Chemical List Presence Keywords (keywords developed to index general information about how chemicals are used from public chemical lists) (Dionisio et al. (2015), Koval et al. (2022)). ChemExpo also makes use of harmonized U.S. EPA chemical identifiers called Distributed Structure-Searchable Toxicity Database (DSSTox) Substance Identifiers (DTXSIDs) (Grulke et al. (2019)), allowing for direct linking to other chemical information in the CompTox Dashboard.

The new ChemExpo application will display more detailed curated CPDat data than currently available on the CompTox Dashboard, including additional document metadata; product-level chemical ingredient information; raw reported information in addition to curated data; and product category, function category, and chemical summaries. All data within ChemExpo were obtained from publicly available primary sources. This application allows for data exploration by chemical, function, PUC, and keyword to support exposure assessments and other risk-based chemical evaluations.

The following sections of this User’s Guide provide an overview of the data available in ChemExpo. It also describes how one would search ChemExpo for specific information or use the application’s interface to explore the available CPDat data. The guide is organized around specific questions users may have about how to use the application for different purposes. For the definitions of specific terms used in the sections below, see the ChemExpo Glossary in Chapter 12.

Data curation within ChemExpo is ongoing, and sometimes makes use of automated methods (noted where appropriate). For more information on the ChemExpo Knowledgebase or to report anything that you feel may be in error contact ChemExpo Support by Email at: chemexpo.support@epa.gov

2.1 Summary of functionality available in V1.0

The initial release of ChemExpo (v1.0) will provide the following functionality. Details of the data, terminology, search functionality, and download procedures are provided in this User Guide.

Users will be able to search for data related to Documents, Products, Chemicals, Product Use Categories, Chemical List Presence Keywords, and Function Categories.
Users will be able to explore available data by Chemical, Product Use Category, Chemical List Presence Keyword, and Function Category.
Users will be able to download data including:
- Metadata (e.g., definitions) related to Product Use Categories, Function Categories, Chemical List Presence Keywords
- Bulk downloads of Composition, Function Category, and Chemical List Presence datasets
- Data downloads related to specific chemicals, Product Use Categories, Function Categories, and Data Documents

Dionisio, Kathie L., Alicia M. Frame, Michael-Rock Goldsmith, John F. Wambaugh, Alan Liddell, Tommy Cathey, Doris Smith, et al. 2015. “Exploring Consumer Exposure Pathways and Patterns of Use for Chemicals in the Environment.” Toxicology Reports 2: 228–37. https://doi.org/10.1016/j.toxrep.2014.12.009.

Dionisio, Kathie L., Katherine Phillips, Paul S. Price, Christopher M. Grulke, Antony Williams, Derya Biryol, Tao Hong, and Kristin K. Isaacs. 2018. “The Chemical and Products Database, a Resource for Exposure-Relevant Data on Chemicals in Consumer Products.” Scientific Data 5 (1). https://doi.org/10.1038/sdata.2018.125.

Grulke, Christopher M., Antony J. Williams, Inthirany Thillanadarajah, and Ann M. Richard. 2019. “EPA’s DSSTox Database: History of Development of a Curated Chemistry Resource Supporting Computational Toxicology Research.” Computational Toxicology 12 (November): 100096. https://doi.org/10.1016/j.comtox.2019.100096.

Isaacs, Kristin K., Kathie Dionisio, Katherine Phillips, Charles Bevington, Peter Egeghy, and Paul S. Price. 2020. “Establishing a System of Consumer Product Use Categories to Support Rapid Modeling of Human Exposure.” Journal of Exposure Science and Environmental Epidemiology 30 (1): 171–83. https://doi.org/10.1038/s41370-019-0187-5.

Koval, Lauren E., Kathie L. Dionisio, Katie Paul Friedman, Kristin K. Isaacs, and Julia E. Rager. 2022. “Environmental Mixtures and Breast Cancer: Identifying Co-Exposure Patterns Between Understudied Vs Breast Cancer-Associated Chemicals Using Chemical Inventory Informatics.” Journal of Exposure Science and Environmental Epidemiology 32 (6): 794–807. https://doi.org/10.1038/s41370-022-00451-8.

Phillips, Katherine A., John F. Wambaugh, Christopher M. Grulke, Kathie L. Dionisio, and Kristin K. Isaacs. 2017. “High-Throughput Screening of Chemicals as Functional Substitutes Using Structure-Based Classification Models.” Green Chemistry 19 (4): 1063–74. https://doi.org/10.1039/c6gc02744j.