Fish Count, Too - the Animal Toll of REACH Aquatic Toxicity Tests.

The European Union’s main chemicals regulation, Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), requires chemicals to be evaluated for health and environmental impacts, with animal tests the basis for many evaluations. Most discussions of REACH animal use focus on mammals, yet fish tests are also a significant component. Here we report the animal count for fish tests completed, ongoing, and pending under REACH, based directly on test reports. The esti­mated total to date is 382,000 fish used for short-term fish toxicity, long-term fish toxicity, endocrine disruption, and bioaccumulation tests. This count does not include new tests that will result from the 2022 REACH amendment, which extends requirements for long-term fish toxicity tests and removes the most common basis for waivers previously accepted for this test. An estimated 940−1,240 new long-term fish toxicity tests may result from these changes, requiring 520,000−680,000 fish. The count also does not include the potential expansion of endocrine disruption testing in the upcoming REACH revision. New non-animal alternatives to long-term fish toxicity and endocrine disruption tests are needed to reduce these impacts. For other fish tests, recently defined non-animal methods for short-term toxicity and the newly approved Hyalella azteca bioconcentration test for bioaccu­mulation should be evaluated for inclusion in REACH guidance, both to incentivize their use and to better comply with the REACH mandate to use animal testing only as a last resort.