Spring 2021
Gradient collaborated with the Humane Society of the US to promote innovative toxicology strategies to both improve chemical safety assessment as well as minimize the use of animal testing.
In 2017, the Humane Society of the United States (Humane Society of the US) and Gradient collaborated to provide comments to US EPA on the implementation of the provisions under the Toxic Substances Control Act (TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act (LCSA). Comments were submitted on behalf of members and supporters of the Humane Society of the US (the nation’s largest animal protection organization) who share the common goal of promoting the use of reliable and relevant regulatory chemical testing methods and strategies that protect human health and the environment while reducing, and ultimately eliminating, the use of animal testing to determine chemical toxicity. Gradient worked jointly with the Humane Society of the US to prepare comments focused on promoting innovative toxicology strategies to both improve chemical safety assessment as well as minimize the use of animal testing in such assessments.
We commented on a number of issues related to US EPA’s proposed rules for chemical prioritization and risk evaluation. Our comments include suggestions related to 1) how exposures and risks would be evaluated across the full life cycle of the substance being evaluated (i.e., manufacturing, processing, distribution, use, and disposal); 2) how susceptible subpopulations would be evaluated; 3) what data would be considered “sufficient” for the evaluation; 4) what constitutes the “best available science” for the risk evaluations; 5) how systematic reviews and weight-of-evidence evaluations would be conducted; 6) development of a robust read-across and chemical-grouping approach, such that the evaluations of data-rich compounds can be leveraged to the extent possible; and 7) the vital roles of alternative methods, including targeted in vitro testing, computational toxicology, quantitative structure activity relationship (QSAR) analysis, read-across, high-throughput screening, and genomic response assays in the prioritization and risk evaluation process. See the Cohen and Lewandowski article in Trends Issue 71, which focused on these testing strategies.
US EPA’s goal is to fully eliminate the use of mammals for chemical testing by 2035.”
Our comments included several approaches for avoiding animal testing while at the same time fulfilling sufficiency of information requirements. In addition to recommendations for non-animal testing data, we provided recommendations for waiving of animal testing data. Our recommendations were based on frameworks applied outside of the US (e.g., Europe, and Australia) and included a list of criteria to consider for waiving of numerous animal tests, including skin sensitization, repeat dose, reproductive and developmental, acute, and aquatic toxicity studies. Since the submission of our comments, US EPA has made substantial progress towards the avoidance of animal testing, issuing guidance on alternative test methods or strategies (New Approach Methodologies, or NAMs) that do not require new vertebrate animal testing, as well as guidance for reducing unnecessary testing on birds, on fish, and most recently (January 2021) on animal skin. US EPA’s goal is to fully eliminate the use of mammals for chemical testing by 2035.
Chemical prioritization was a focus of our comments, given the utility – from both an efficiency and animal welfare perspective – of being able to “screen out” chemicals without engaging in unnecessary testing that is unlikely to elucidate new information on chemical hazard. Therefore, we provided examples of several chemical prioritization frameworks that have been applied outside of the US (i.e., Canada, Europe, and Australia), in addition to the Health and Environmental Sciences Institute (HESI) RISK21 approach that is the result of a multisector and multinational effort engaging over 120 participants from 12 countries, including universities, government institutions, and non-government organizations. Our recommendation for application of these frameworks was to propose a tool for visualization of the uncertainty that drives data gathering on hazard and exposure, and help prioritize “candidates for information gathering” into high- or low-risk categories. Application of these frameworks can promote a better understanding of the uncertainties stemming both from data variability and from lack of information (related to exposure and hazard), thus helping to 1) identify substances that are clearly high or low priority for evaluation under TSCA; and 2) focus questions on what data are needed and how data gaps can be filled with consideration of alternatives to animal testing.
Our comments were considered by US EPA in finalizing the rules for chemical prioritization and risk evaluation, and in developing its prioritization and risk evaluation guidelines aimed at improving chemical safety and minimizing the use of animal testing.
The author can be reached at lbailey@gradientcorp.com.