Animal testing regulations in the United States come from several overlapping sources rather than a single federal law. The Animal Welfare Act sets baseline care standards for certain species, the Public Health Service Policy governs federally funded research and covers the animals the AWA leaves out, and separate rules from the FDA, EPA, CDC, and Fish and Wildlife Service apply depending on what is being tested and where the animals come from. What any given laboratory must do depends on the species, the funding source, and whether the work supports a regulated product like a drug or pesticide.
The Animal Welfare Act
The Animal Welfare Act, codified at 7 U.S.C. § 2131 and following sections, is the main federal statute governing animals in research settings.1Office of the Law Revision Counsel. 7 U.S.C. 2131 – Congressional Statement of Policy It requires minimum standards of housing, feeding, and veterinary care for certain warm-blooded animals used in research, exhibition, and commercial sale, including dogs, cats, nonhuman primates, guinea pigs, hamsters, and rabbits.2National Agricultural Library. Animal Welfare Act
The Act’s most consequential feature is what it leaves out. The statutory definition of “animal” excludes birds, rats of the genus Rattus, and mice of the genus Mus when bred for research.3Office of the Law Revision Counsel. 7 U.S.C. 2132 – Definitions Those species make up the vast majority of laboratory animals in the United States. A facility working exclusively with purpose-bred rats and mice has no obligation to register with the USDA or accept its inspections under this statute. Farm animals used for agricultural purposes and horses not used in research are also excluded.4eCFR. 9 CFR 1.1 – Definitions
USDA Enforcement and Penalties
Day-to-day enforcement falls to the USDA’s Animal and Plant Health Inspection Service. Inspectors conduct unannounced visits to licensed and registered facilities and review housing, sanitation, ventilation, veterinary care, and recordkeeping.5Animal and Plant Health Inspection Service. Animal Welfare Act Enforcement Research facilities using regulated species must be inspected at least once a year.6Animal and Plant Health Inspection Service. AWA Inspection and Annual Reports
When violations turn up, APHIS can issue an official warning, negotiate a settlement with a financial penalty, or refer the matter to USDA administrative law judges or the Department of Justice.7Animal and Plant Health Inspection Service. Enforcement Summaries The statutory baseline is up to $10,000 per violation, with each violation on each day counted separately.8Office of the Law Revision Counsel. 7 U.S.C. 2149 – Violations by Licensees After inflation adjustments, the current maximum stands at $14,575 per violation per day, and knowingly ignoring a cease-and-desist order carries an additional $2,185 per day.9Federal Register. Civil Monetary Penalty Inflation Adjustments for 2025
Registered research facilities also file annual reports with the USDA documenting every regulated animal used, sorted by the level of pain or distress involved. Procedures that caused pain where medication was withheld require a written explanation of why.
Public Health Service Policy
The Public Health Service Policy on Humane Care and Use of Laboratory Animals fills the gap the AWA leaves. Rooted in the Health Research Extension Act of 1985, it applies to every institution receiving funding from the National Institutes of Health or any other PHS agency.10National Institutes of Health. Health Research Extension Act of 1985 Crucially, it covers all live vertebrate animals, including the rats, mice, and birds excluded from the AWA.11National Institutes of Health. Public Health Service Policy on Humane Care and Use of Laboratory Animals
Before an institution can receive any NIH grant money, it must file an Animal Welfare Assurance with the Office of Laboratory Animal Welfare (OLAW). The assurance is a binding commitment to follow the Guide for the Care and Use of Laboratory Animals and maintain an active internal review committee.12National Institutes of Health. Animal Welfare (OLAW) The leverage is financial: OLAW can restrict or withdraw approval, cutting off federal funding.
Institutions submit annual reports to OLAW covering the federal fiscal year (October 1 through September 30), due by December 1. Reports must disclose changes in accreditation, animal care programs, IACUC membership, the dates of semiannual program reviews, and any minority views filed by committee members.13National Institutes of Health. Annual Report to OLAW
Institutional Animal Care and Use Committees
Both the AWA and the PHS Policy require every research facility to run an Institutional Animal Care and Use Committee, or IACUC. No animal research can begin without its approval. The committee must have at least three members, including a veterinarian with laboratory animal experience who holds program responsibility for the facility, and at least one member unaffiliated with the institution who represents general community interests.14eCFR. 9 CFR 2.31 – Institutional Animal Care and Use Committee (IACUC) If the committee has more than three members, no more than three can come from the same administrative unit.
Researchers submit protocols before starting work. For any procedure expected to cause more than momentary pain, the proposal must include a written narrative explaining what alternatives were considered and why they were not feasible.14eCFR. 9 CFR 2.31 – Institutional Animal Care and Use Committee (IACUC) The committee can approve, require changes, or reject the protocol. This is where the “three Rs” get applied in practice: replacing animals with non-animal models where possible, reducing the number used, and refining procedures to minimize suffering.
The IACUC also inspects animal facilities at least every six months, evaluates the veterinary care program, and verifies training. Federal rules require personnel training in humane handling for each species, surgical technique, pre- and post-procedure care, and awareness of methods that could replace or reduce animal use.15eCFR. 9 CFR 2.32 – Personnel Qualifications
When Testing Is Effectively Required
Some animal studies aren’t just allowed; they are the practical price of getting a product to market. The Federal Food, Drug, and Cosmetic Act at 21 U.S.C. § 355 requires manufacturers to submit “full reports of investigations” showing a new drug is safe, and FDA guidance has long interpreted that to include testing in at least two mammalian species, typically a rodent and a non-rodent.16Office of the Law Revision Counsel. 21 U.S.C. 355 – New Drugs
The EPA imposes a parallel framework for pesticides. Under the Federal Insecticide, Fungicide, and Rodenticide Act, companies must submit comprehensive health and safety data before a pesticide can be registered for sale, and that package traditionally includes acute, chronic, and reproductive toxicity studies in animals.17US EPA. Data Requirements for Pesticide Registration
Good Laboratory Practice Standards
Animal studies used to support drug or chemical approvals have to meet the Good Laboratory Practice regulations at 21 CFR Part 58. Facilities must run a quality assurance unit that independently monitors ongoing work, follow written standard operating procedures, use properly calibrated equipment, and adhere to specific protocols for housing and test-substance handling.18eCFR. 21 CFR Part 58 – Good Laboratory Practice for Nonclinical Laboratory Studies Every study operates under a written protocol, and results must be documented and retained. Data from studies that fall short of GLP can be rejected outright.
The FDA Modernization Act 2.0
In late 2022, Congress passed the FDA Modernization Act 2.0. It amended the Federal Food, Drug, and Cosmetic Act by replacing “preclinical tests (including tests on animals)” with the broader term “nonclinical tests,” then defined that term to include cell-based assays, organ-on-chip systems, bioprinted models, and computer simulations alongside animal studies.19Congress.gov. S.5002 – FDA Modernization Act 2.0
The change is narrower than it sounds. The law does not ban or reduce animal testing; it removes the statutory language that specifically required it. FDA guidance still describes the traditional two-species framework, and an FDA spokesperson said publicly that the new law “does not change the regulatory process for drugs.” Companies can now propose non-animal approaches, but the FDA still decides whether those approaches produce enough confidence to move a drug into human trials.
EPA Efforts to Reduce Animal Testing
The EPA has taken a more direct stance on reducing animal use. The Toxic Substances Control Act, as amended by the Lautenberg Chemical Safety for the 21st Century Act, directs the agency to replace vertebrate animal testing “to the extent practicable and scientifically justified” and to promote alternative methods, with progress reports to Congress every five years.20US EPA. Alternative Test Methods and Strategies to Reduce Vertebrate Animal Testing
The EPA calls these alternatives New Approach Methodologies, a category that includes computational models, cell-based assays, and other technologies that generate hazard data without intact animals. The agency maintains and annually updates a list of accepted methods. Uptake has been gradual, because regulators still have to be convinced that a model or cell system predicts what happens in a living organism as reliably as a whole-animal study.
Cosmetics: State Bans, No Federal Mandate
Cosmetics sit outside the drug and pesticide framework. The FDA does not require specific tests to demonstrate cosmetic safety, so animal testing for cosmetics has never been federally mandated. Regulation instead has grown up at the state level: roughly a dozen states prohibit selling cosmetics developed or manufactured using animal testing conducted after a specified date. These laws generally bar manufacturers from importing or selling a product if they knew or should have known animal testing was performed on the finished product or its ingredients.
Most state bans carve out exceptions for testing required by a federal agency or a foreign regulator, so companies forced to run animal studies for another country’s market don’t automatically violate a state law. The Modernization of Cosmetics Regulation Act of 2022 included a “sense of Congress” statement that cosmetics animal testing should be phased out, but stopped short of a federal prohibition. Manufacturers increasingly rely on validated alternatives such as reconstructed skin models, cell-based irritation tests, and computational toxicology.
Importing Research Animals
Facilities importing animals face a separate layer of federal rules. Nonhuman primates are the most tightly controlled category. Under 42 CFR § 71.53, importers must register with the CDC and make their facilities, vehicles, equipment, animal health records, and even employee health records available for inspection.21eCFR. 42 CFR 71.53 – Requirements for Importers of Nonhuman Primates The rules exist to prevent communicable diseases from spreading from imported primates to humans.
When the species is listed under the Convention on International Trade in Endangered Species (CITES), an additional permit from the U.S. Fish and Wildlife Service is required before the animal can cross the border. CITES treats any cross-border movement of a listed species as regulated trade, and permits issue only after the agency determines the specimen was legally acquired and the trade will not threaten the species’ survival in the wild.22U.S. Fish and Wildlife Service. CITES A researcher working with an endangered primate must satisfy both the CDC’s disease-prevention framework and the Fish and Wildlife Service’s conservation requirements before the animal arrives.