Key Opportunities to Replace, Reduce and Refine Regulatory Fish Acute Toxicity Tests.

Fish acute toxicity tests are conducted as part of regulatory hazard identification and risk assessment packages for industrial chemicals and plant protection products. The aim of these tests is to determine an LC50 endpoint - that is, the concentration which would be lethal to 50% of the animals treated. These tests are therefore associated with suffering in the test animals, and OECD Test Guideline 203 (fish, acute toxicity) studies are the most widely conducted regulatory vertebrate ecotoxicology tests for prospective chemical safety assessment. There is great scope to apply the 3Rs principles - the reduction, refinement and replacement of animals - in this area of testing. An expert ecotoxicology working group, led by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), including members from government, academia and industry, reviewed global fish acute test data requirements for the major chemical sectors. This article highlights ongoing initiatives and provides an overview of the key challenges and opportunities associated with replacing, reducing and/or refining fish acute toxicity studies - without compromising environmental protection. This article is protected by copyright. All rights reserved.