Question to the Department for Science, Innovation & Technology:

To ask the Secretary of State for Science, Innovation and Technology, with reference to her Department’s publication entitled Replacing animals in science: A strategy to support the development, validation and uptake of alternative methods, published on 11 November 2025, what steps she is taking to end the use of the LD50 and LC50 tests.

The Strategy uses a ‘baskets’ approach to group animal tests according to how ready they are for replacement, based on the maturity of potential alternative methods. These initial baskets are not exhaustive and will be reviewed and refined in consultation with the research community on a regular basis, noting that two LD/LC50 tests are already in basket 1 and 2 (botulinum potency and fish acute toxicity tests respectively) meaning they are among the first targeted for phase-out.

In addition, the Government-funded National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) has ongoing work to replace, reduce and refine LD/LC50 tests.