OECD Guidelines for the Testing of Chemicals, Section 4
- 2074-5788 (online)
The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. They are a set of tools for professionals, used primarily in regulatory safety testing and subsequent chemical and chemical product notification, chemical registration and in chemical evaluation. They can also be used for the selection and ranking of candidate chemicals during the development of new chemicals and products and in toxicology research. This group of tests covers health effects.
Test No. 442E: In Vitro Skin Sensitisation
Human Cell Line Activation Test (h-CLAT)
- 29 July 2016
- 9789264264359 (PDF)
The present Test Guideline addresses the human health hazard endpoint skin sensitisation, following exposure to a test chemical. Skin sensitisation refers to an allergic response following skin contact with the tested chemical, as defined by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). This Test Guideline (TG) provides an in vitro procedure (the human cell Line Activation Test h-CLAT method) used for supporting the discrimination between skin sensitisers and non-sensitisers in accordance with the UN GHS. The h-CLAT method is proposed to address the third key event of the skin sensitisation AOP by quantifying changes in the expression of cell surface markers associated with the process of activation of monocytes and dendritic cells (DC) (i.e. CD86 and CD54), in the human monocytic leukaemia cell line THP-1, following exposure to sensitising test chemical. These surface molecules are typical markers of monocytic THP-1 activation and may mimic DC activation, which plays a critical role in T-cell priming. The changes of surface marker expression are measured by flow cytometry following cell staining with fluorochrome-tagged antibodies. The relative fluorescence intensity of surface markers compared to solvent/vehicle control are calculated and used in the prediction model, to support the discrimination between sensitisers and non-sensitisers.