This Test Guideline addresses the human health hazard endpoint skin sensitisation, following exposure to a test chemical. It provides an in chemico procedure (Direct Peptide Reactivity Assay – DPRA) used for supporting the discrimination between skin sensitisers and non-sensitisers.

The present Key Event based Test Guideline (TG) 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 TG is proposed to address the activation of dendritic cells, which is one Key Event on the Adverse Outcome Pathway (AOP) for Skin Sensitisation. It provides four in vitro test methods addressing the same Key Event on the AOP: (i) the human cell Line Activation Test or h-CLAT method, (ii) the U937 Cell Line Activation Test or U-SENS, (iii) the Interleukin-8 Reporter Gene Assay or IL-8 Luc assay and (iv) the Genomic Allergen Rapid Detection for assessment of skin sensitisers (GARDTMskin). All of them are used for supporting the discrimination between skin sensitisers and non-sensitisers in accordance with the UN GHS. The test methods described in this TG either quantify the change in the expression of cell surface marker(s) CD54 and CD86, the cytokine IL-8, or a series of genes (genomic biomarker signature) that are associated with the process of activation of monocytes and DC following exposure to sensitisers.

This Test Guideline (TG) provides an in vitro procedure (the ARE-Nrf2 luciferase test method) used for supporting the discrimination between skin sensitisers and non-sensitisers in accordance with the UN GHS.

A Defined Approach (DA) consists of a selection of information sources (e.g in silico predictions, in chemico, in vitro data) used in a specific combination, and resulting data are interpreted using a fixed data interpretation procedure (DIP) (e.g. a mathematical, rule-based model). DAs use methods in combination and are intended to overcome some limitations of the individual, stand-alone methods.

Hayes’ Principles and Methods of Toxicology has long been established as a reliable and informative reference for the concepts, methodologies, and assessments integral to toxicology. The new edition contains updated and new chapters with the addition of new authors while maintaining the same high standards that have made this book a benchmark resource in the field. Key Features: The comprehensive yet concise coverage of various aspects of fundamental and applied toxicology makes this book a valuable resource for educators, students, and professionals. Questions provided at the end of each chapter allow readers to test their knowledge and understanding of the material covered. All chapters have been updated and over 60 new authors have been added to reflect the dynamic nature of toxicological sciences New topics in this edition include Safety Assessment of Cosmetics and Personal Care Products, The Importance of the Dose/Rate Response, Novel Approaches and Alternative Models, Epigenetic Toxicology, and an Expanded Glossary. The volume is divided into 4 major sections, addressing fundamental principles of toxicology (Section I. "Principles of Toxicology"), major classes of established chemical hazards (Section II. "Agents"), current methods used for the assessment of various endpoints indicative of chemical toxicity (Section III. "Methods"), as well as toxicology of specific target systems and organs (Section IV. "Organ- and System-Specific Toxicology"). This volume will be a valuable tool for the audience that wishes to broaden their understanding of hazards and mechanisms of toxicity and to stay on top of the emerging methods and concepts of the rapidly advancing field of toxicology and risk assessment.

This document describes the state of knowledge of the adverse outcome pathway (AOP) for skin sensitisation initiated by covalent binding to proteins, assesses the weight-of-evidence supporting the AOP, identifies the key events, and identifies databases containing test results related to key events.