# Federal Register #FDA-2026-N-5347

FDA Direct Final Rule Modernizes Nonclinical Testing Terminology in Drug and Biological Product Regulations

**Buyer:** Food and Drug Administration (FDA)
**Posted:** September 22, 2026
**Respond By:** December 07, 2026
**Identifier:** FDA-2026-N-5347

The Food and Drug Administration (FDA), part of the Department of Health and Human Services, has issued a direct final rule updating terminology in its drug and biological product safety testing regulations.
- Government Buyer:
  - Department of Health and Human Services
  - Food and Drug Administration (FDA)
- Regulatory Update Details:
  - Replaces references to 'animal' tests or studies with 'nonclinical' tests or studies
  - Adds definitions for 'nonclinical test' and 'nonclinical study'
  - Updates terminology from 'preclinical' to 'nonclinical' and 'in vitro' for consistency
  - Makes conforming amendments in safety and reporting sections
- Purpose and Impact:
  - Reduces emphasis on animal testing as the sole methodology for safety assessment
  - Promotes development and use of scientifically valid new testing methodologies, including non-animal methods (in vitro, in silico, in chemico)
  - Aligns regulatory language with recent legislative amendments and scientific progress
- No procurement activity:
  - No products, services, OEMs, or vendors are requested or mentioned
  - No new testing requirements are imposed; only terminology is updated
- Notable Requirements:
  - Regulatory language modernization to support alternative testing methods
  - Effective date and comment period specified in the rule

### Description

The Food and Drug Administration (FDA) is issuing a direct final rule that replaces references to "animal" tests or studies with "nonclinical" tests or studies, adds definitions for "nonclinical test" and "nonclinical study," and makes other conforming amendments in certain safety and reporting sections of its regulations. The rule also replaces "preclinical" with "nonclinical" and "in vitro" for consistency. These amendments aim to remove emphasis on animal testing as the sole scientific methodology for safety assessment, fostering the development and use of scientifically valid new testing methodologies, potentially improving predictive accuracy of product safety testing while reducing, refining, or replacing animal use. The rule is scheduled to become effective on February 4, 2027, with a comment period ending December 7, 2026.

[View original listing](https://www.federalregister.gov/documents/2026/09/22/2026-19349/nonclinical-testing-terminology)