Redefining the gold standard and recommendations to accelerate the adoption of New Approach Methodologies (NAMs) in support of the Three Rs

Traditionally, animal testing has been considered the 'gold standard' in determining potential effects of chemicals on humans. However, this dogma is increasingly being questioned, not only due to ethical and financial implications, but also because of the poor translatability of the results of animal tests to humans. Therefore, there is a need to modernise the concept of the gold standard and ensure that any new approach is flexible, adaptable and as future-proof as possible. Herein, we reflect on recent suggestions for updating, or redefining, the traditional gold standard of animal testing and propose a new definition. This proposal focuses more on the process of answering a specific question, using all available tools, rather than seeking to recapitulate an animal test. New Approach Methodologies (NAMs) provide an ever-expanding array of tools that can assist product development and play a key role in chemical assessment strategies. Ten recommendations for developing fit-for-purpose NAMs, to increase their acceptance and accelerate their adoption, are presented.