On June 30, 2022, the OECD published new Test Guidelines (TGs).

While the first defined approaches were published on skin sensitization (OECD TG 497) in 2021, the new OECD TG 467 describes defined approaches for serious eye damage and eye irritation using new approach methodologies (NAMs). The methods used in the defined approaches, DAL-1 and DAL-2, encompass the Bovine Corneal Opacity and Permeability (BCOP) using the laser light-based opacitometer according to the OECD TG 437, the Reconstructed human Cornea-like Epithelium (RhCE) according to the OECD TG 492B, see below, and the Short Time Exposure in vitro (STE) according to the OECD TG 491.

OECD TG 492B describes the SkinEthic™ Human Corneal Epithelium (HCE) Time-to-Toxicity (TTT) test using a commercially available reconstructed HCE that discriminates the three UN GHS categories for serious eye damage/eye irritation, i.e. UN GHS Cat. 1, Cat. 2 and No Cat chemicals. It is recommended as a full replacement to the in vivo Draize acute eye irritation test for classification of chemicals.

OECD TG 442E, which describes in vitro assays that address mechanisms described under the key event on activation of dendritic cells of the AOP for skin sensitisation, was updated to include the Genomic Allergen Rapid Detection (GARD™) for assessment of skin sensitisers (GARD™skin) in addition to the Human Cell Line Activation test (h-CLAT), U937 cell line activation Test (U-SENS™), and Interleukin-8 Reporter Gene Assay (IL-8 Luc assay). The GARD™skin assay is the first harmonized method to use gene expression as a regulatory endpoint.

New non-animal Test Guidelines:  

  • TG 467: Defined Approaches for Serious Eye Damage and Eye Irritation
  • TG 492B: Reconstructed Human Cornea-like Epithelium (RHCE) Test Method for Eye Hazard Identification - an in vitro procedure for the identification on its own of chemicals (substances and mixtures) according to the UN GHS ocular hazard categories.
  • TG 251: Rapid Androgen Disrupter Activity Reporter (RADAR) assay - an aquatic assay that utilizes transgenic Oryzias latipes (Japanese medaka) eleutheroembryos to detect chemicals active on the androgen axis.

Corrections and updates:  

  • TG 442C: In Chemico Skin Sensitisation - includes updates on the amino acid derivative reactivity assay (ADRA) for skin sensitization and includes updated performance standards for the direct peptide reactivity assay (DPRA) and ADRA.
  • TG 442D: In Vitro Skin Sensitisation - minor text corrections to clarify a discrepancy regarding controls.
  • TG 442E: In Vitro Skin Sensitisation - updated to include the GARD™skin assay.
  • TG 456: H295R Steroidogenesis Assay - amendments to the data interpretation procedure.

Consult OECD Guidelines for the Testing of Chemicals for Health Effects (Section 4) and Effects on Biotic Systems (Section 2) for further OECD test guidelines.