News | Jul 14, 2026
OECD Releases 2026 Test Guideline Updates
Written by ICAPO secretariat Eryn Slankster-Schmierer, PhD, and reviewed by ICAPO.
ICAPO works on prioritization, development, and adoption of nonanimal methods by participating in the Working Party of the National Coordinators of the Test Guideline (TG) Programme as invited experts. Members of ICAPO co-lead projects, engage in expert group discussions and activities that influence TG development, and provide comments to prioritize nonanimal methods. We also provide our input through participation at the annual meeting in April. Several outcomes of the 2026 meeting were recently published.
New Nonanimal Methods to the Test Guideline Programme
NEW! Test Guideline on the Determination of Cytochrome P450 (CYP) Induction using Differentiated Human Hepatic Cells. This guideline uses human-derived metabolic competent hepatic test systems to assess the potential of test chemicals to induce three biotransformation enzymes.
NEW! Guidance Document for in vitro testing of the Intestinal Fate of Orally Ingested Nanomaterials
NEW! Two new test methods were added to update TG 442D on in vitro skin sensitisation, adding to the repertoire of in vitro methods available to address Key Event 2 for skin sensitisation:
- Epi2SensA was added as Appendix 1C
- α-Sens® was added as Appendix ID, a method free from fetal bovine serum
NEW! Test Guideline on the ToxTracker assay, an in vitro assay for genotoxicity testing.
NEW! Test Guideline on the Glucocorticoid Receptor Transactivation Assay provides an in vitro test for detection of agonistic and antagonist activity of chemicals to the human glucocorticoid receptor.
Updated TG 497 Defined Approaches on Skin Sensitisation was updated for inclusion of a regression model for derivation of a quantitative point of departure
Updated Test Guideline 498 on In Vitro Photoxicity was updated to include the KeraskinTM Phototoxicity assay
OECD Test Guidelines Explorer was launched
ICAPO member Cruelty Free International conceptualized and funded the pilot initiative to increase visibility of the OECD’s Test Guidelines, which resulted in the OECD Test Guideline Explorer tool. The initiative currently features human health endpoints, and allows filtering and easily accessible visual comparisons across guidelines. For example, it is now easy to filter by in vitro, in chemico, or in silico methods and by endpoint. The explorer easily allows you to see and compare information across test guidelines as well as access technical limitations of assays.
For a complete list of nonanimal TGs, visit ICAPO.org/test-guidelines. For a complete list of Test Guideline updates in 2026, visit the OECD’s Guidelines for the Testing of Chemicals.