Validation of Test Methods

Revision of the OECD Guidance Document on Validation and International Acceptance

On behalf of the Netherlands, Bureau REACH organized an important meeting on 9 and 10 December of an OECD (Organisation for Economic Co-operation and Development) project group focused on revising and updating a guidance document on test method validation and international acceptance (OECD Guidance Document No. 34). The Netherlands leads this project group together with experts from the United States and the Joint Research Centre of the European Commission. More than 40 experts from various OECD member countries, industry and NGOs participated in the meeting. Dutch representatives gave presentations on previous OECD workshops and meetings related to validation, as well as on the ‘readiness’ criteria for test methods.

The revision of OECD Guidance Document No. 34 is necessary to make it more suitable for innovative test methods such as New Approach Methodologies (NAMs) and Defined Approaches (systematic frameworks in which multiple methods are integrated or combined). Furthermore, the guidance needs to be clarified by establishing ‘readiness’ criteria for test methods, both prior to and during the validation process, with a specific focus on test method developers.

European Test Method & Validation Strategy for Regulatory Chemical Risk Assessment

During a CARACAL meeting in July 2024, the Netherlands (Ministry of Infrastructure and Water Management supported by Bureau REACH) and Germany presented a proposal to develop a European strategy for the development and validation of test methods, in collaboration with policy experts from the REACH and CLP authorities. The proposal was well received by stakeholders present, though there was some uncertainty about the challenges involved and potential next steps. In December 2024, ECHA, together with Dutch and German colleagues, organized a technical workshop for experts from the European Commission, EU Member States, and the OECD to clearly identify the issues surrounding test method development and validation.

New test methods often make their way into legislation only slowly and with difficulty. This is partly due to insufficient attention to regulatory needs during method development and a lack of funding for validation. The strategy aims to accelerate this process by improving coordination and funding at the European level, in collaboration with other key stakeholders such as the European Commission, NGOs, and industry.