Alternative Test Methods and Strategies to Reduce Vertebrate Animal Testing
In January 2026, Administrator Zeldin signed a memo recommitting the agency to eliminate testing on mammals by the year 2035. EPA's Office of Chemical Safety and Pollution Prevention is prioritizing the development and implementation of high-quality alternatives to reduce testing on vertebrate mammals, like rabbits, mice, rats, and dogs, to align with regulatory requirements, the high bar of gold standard science and EPA's Make America Healthy Again agenda.
The Toxic Substances Control Act (TSCA) directs EPA to:
- reduce and replace, to the extent practicable and scientifically justified, the use of vertebrate animals in the testing of chemical substances or mixtures; and
- promote the development and timely incorporation of alternative test methods or strategies that do not require new vertebrate animal testing.
TSCA also requires EPA to maintain and regularly update a list of New Approach Methodologies (NAMs).
On this page:
- General information on NAMs
- Using NAMS in the TSCA program
- NAMs Nomination Process
- Additional information
On other pages:
General Information on NAMS
NAMs refer to any technology, methodology, approach (including computational/in silico models like QSARs), or combination thereof that can be used to provide information on chemical hazard and risk assessment that avoids the use of intact animals. For the purposes of TSCA, EPA recognizes this new term (i.e., NAMs) as encompassing any “alternative test methods and strategies to reduce, refine, or replace vertebrate animals.”
Examples of NAMs would be in vitro tests or assays, in chemico assays and in silico algorithms. In vitro studies are experiments which use human or animal cells. In chemico studies are experiments which do not use any human or animal cells, but simply evaluate how a chemical interacts/reacts with certain materials. Finally, in silico is the term used for computer-driven predictive tools.
Another example includes the use of analogue/read-across approaches to evaluating toxicity. If you have a chemical (target chemical) for which you have no toxicity information, you may be able to use information available on a structurally similar chemical (analogue) in a read-across approach. Another example would be to apply the principles of QSAR to predict toxicity.
Using NAMs in the Chemical Safety Program
EPA’s Office of Chemical Safety and Pollution Prevention covers many chemicals consisting of a wide spectrum of chemistries, from simple organic molecules to complex mixtures, reaction products, and polymers.
Using NAMs, like human cell models and advanced computer methods, helps EPA identify hazards and exposures faster and often with results that are more relevant to people. These tools can cut costs and time, reduce animal use, and provide clearer insight into how a chemical works in the body. The result is quicker, more transparent safety decisions that better protect families, workers, and communities while giving businesses clear, up‑to‑date expectations.
EPA is working internally and with stakeholders to identify, develop, and use NAMs to evaluate new and existing chemicals and pesticides. The agency is also working on a number of initiatives to implement NAMs in pesticide and chemical reviews.
TSCA NAMs Nomination Process
Stakeholders can submit NAMs related to chemical reviews and associated data to EPA through the agency's TSCA NAMs Nomination Process. EPA reviews these methods to make sure they are scientifically sound, looking at transparency of the approach, relevance to human biology, reliability and reproducibility of results, and whether the method is fit for its intended purpose.
EPA anticipates considering nominated NAMs across multiple TSCA decision contexts, such as prioritization, screening, and informing risk determinations for new or existing chemicals, while applying a fit-for-purpose approach, recognizing that a method is suitable for one context and may not be appropriate for another. Most NAMs currently on the List are expected to contribute as part of a weight of scientific evidence framework for characterizing modes of action or hazards, though some may be combined to meet specific regulatory needs, such as OECD defined approaches that integrate results from multiple methods.
Additional Information on NAMs
In addition to the work EPA is doing to integrate the use of NAMs into the TSCA program, other programs within OCSPP and across the Agency are working on the development and use of NAMs.
- OPP Strategic Vision for Adopting 21st Century Science Methodologies for pesticide regulation
- Workplan for using NAMS in the Endocrine Disruptor Screening Program (EDSP)
- Center for Computational Toxicology and Exposure (CCTE)
- National Center for Environmental Research (NCER)
- Chemical Safety for Sustainability Research Program (CSS)
For more information on the use of NAMs in the TSCA program, email NAM@epa.gov.