Regulatory Alert: New OECD Test Guidelines (2026)

Significant Toxicological Advancements Supporting the Phase-Out of Animal Testing

The OECD released its latest test guideline updates on July 2, 2026, bringing significant advancements to toxicological assessments while supporting the global phase-out of animal testing. These updates introduce major revisions for skin sensitisation, including updates to OECD TG 497 to introduce a quantitative Point of Departure (PoD) via the SARA-ICE Defined Approach, alongside newly validated in vitro methods in OECD TG 442D such as Epi2SensA and α-Sens®.

New In Vitro Test Additions

Completely new in vitro tests added to the OECD catalog include:

• OECD TG 446A (Genotoxicity): The ToxTracker gene reporter assay for identifying genotoxic hazards and distinguishing modes of action.
• OECD TG 445A (Metabolism): Determination of Cytochrome P450 (CYP) induction using differentiated human hepatic cells.
• OECD TG 454A (Endocrine Disruption): The Human Glucocorticoid Receptor Transactivation Assay assessing endocrine-disrupting properties at Level 2.

Implications for Ecotoxicological Data Packages

The 2026 updates also introduce critical changes for ecotoxicity data packages:

• Bumble Bees (OECD 255): A new 10-day chronic OECD test guideline published on July 2, 2026, increasing information generated for non-Apis species.
• Earthworm Field Studies (OECD 256): Released on July 2, 2026, assessing effects on earthworm populations under field conditions using diverse test designs and soil residue analysis.
• Algae Testing (OECD 201): Introduces a new diatom test species (Mayamaea permitis) and clarifies specific growth rate calculations.

© 2026 BioAg World Digest | Regulatory Alert: New OECD Test Guidelines