The benefits of validation of methods for toxicity testing outweigh its costs

Abstract

The 4^th Annual Forum on Endocrine Disrupters organized by the European Commission brought together the authors of this article around the topic: “From bench to validated test guidelines: (pre)val­idation of test methods”. Validation activities are meant to demonstrate the relevance and reliability of methods and approaches used in regulatory safety testing. These activities are essential to facil­itate regulatory use, still they are largely underfunded and unattractive to the scientific community. In the last decade, large amounts of funding have been invested in European research towards the development of approaches that can be used in regulatory decision-making, including for the identification of endocrine disrupters. There is a vast pool of candidate test methods for potential reg­ulatory applications, but most of them will not be used due to the absence of consideration of their relevance and reliability outside the method developer’s laboratory. This article explains the reasons why such a gap exists between the outputs of research projects and the uptake in a regulatory context. In parallel, there are also increasing expectations from the regulatory science community that validation becomes more efficient with respect to time and resources. This article shares some of the lessons learned and proposes paths forward for validation of new methods that are not intended as one-to-one replacements of animal studies. This includes submitting only mature methods for validation that were developed following good practices and good documentation, proposing a greater emphasis on well-documented transferability studies, and adopting a cost-sharing model among those who benefit from validated methods.

Plain language summary
Validation activities for methods intended to be used to assess chemical safety have a cost but also bring substantial benefits when the validated methods are established as OECD Test Guidelines, which results in mutual acceptance of data generated by the methods across OECD member and adhering countries. The article discusses some of the challenges faced when method validation is underfunded and unattractive for researchers. Proposals are made to improve the current situation, gain efficiency, and make validation a shared responsibility.