EPA Research Partner Support Story: Priority Products identification
Partner: California Environmental Protection Agency’s (CalEPA) Department of Toxic Substances Control (DTSC)
Challenge: To inform the identification of “Priority Products,” California DTSC must understand the potential for exposures to chemicals contained in specific consumer products
Resource: Application of high-throughput human exposure models for thousands of chemical-product combinations
Project Period: 2017 – 2019
California DTSC’s Safer Consumer Products program uses a multi-step process to reduce toxic chemicals in the products that consumers buy and use. It identifies specific products that contain potentially harmful chemicals and asks manufacturers if the chemical is chemical necessary and if there a safer alternative. DTSC identifies “Candidate Chemicals” which may pose a health hazard, and then identifies “Priority Products” in which they may occur. DTSC would like to consider potential human exposures associated with Candidate Chemicals when deciding which products are a priority. However, since measured exposure data are rarely available for all potential chemicals and products, exposure model predictions are needed.
“The Safer Consumer Product regulations don’t use quantitative risk assessment to prioritize product-chemical combinations as Priority Products. Instead, the regulatory criteria are exposure potential and hazard potential using a narrative standard. So, determining exposure is critical for our decision making. The Stochastic Human Exposure and Dose Simulation High Throughput (SHEDS-HT) model and product intake fraction modeling are valuable tools to help us assess exposure. CA DTSC can use SHEDS-HT to support the selection of Priority Product categories and accelerate our screening of chemicals in our work plan including flame retardants, antimicrobials, per- and polyfluoroalkyl substances (PFAS), and fragrances.” – CalEPA DTSC Director Meredith Williams
EPA ORD’s High-Throughput Stochastic Human Exposure and Dose Simulation Model (SHEDS-HT) is a population- based model of human exposure to chemicals in consumer products that can be used to meet this need. Inputs to SHEDS-HT include product compositions (i.e., chemical concentrations in various product types), human behavior patterns (e.g., frequency and amount of product use), chemical properties, and population characteristics. ORD has also developed a database of product chemical ingredient data called the Chemicals and Products Database (CPDat) by collecting and summarizing data on thousands of products from publicly- available data sources such as Material Safety Data Sheets and manufacturer ingredient lists. Using CPDat, ORD scientists performed SHEDS-HT simulations of the predicted exposures associated with thousands of chemical-consumer product combinations, including chemicals currently included on the DTSC Candidate Chemical List.
DTSC uses SHEDS-HT results to support selection of Priority Product categories and further prioritization or evaluation of products and chemicals. These activities have already directly supported California’s Safer Consumer Products program. One example is California’s assessment of non-occupational 1,4-Dioxane exposure from drinking water and product use.
For more information, visit the Rapid, Exposure and Dosimetry Webpage.