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3Rs in the UK

The Animals (Scientific Procedures) Act 1986 (ASPA) regulates the use of animals in scientific procedures in the UK. The principles of the 3Rs are implicit in the ASPA; all UK scientists are therefore legally obliged to use alternatives approaches to the use of animals where possible, to use the minimum number of animals, and to use protocols which cause the least pain, suffering or distress.


Commercial organisations, universities and other academic establishments (including medical schools) carry out the largest number of scientific procedures under the ASPA.

The commercial sector

Mouse on sleeve of handlerAnimal use in the commercial sector has decreased over recent years, despite increased investment and activity. The pharmaceutical industry, for example, invests in developing high technology replacement alternatives. Robotics and in vitro systems have virtually replaced the use of animals in the early screening processes of drug discovery. However, it is more difficult to replace animal use at more advanced stages of drug screening. Toxicity, vaccine and other forms of safety testing, still require animal models due to the need, in the interests of human safety, to see how new drugs and other substances operate in a whole body system.


Researchers working under the ASPA in academic establishments must meet the provisions of the Act, including the obligation to replace, refine and reduce animal use. The main biological and biomedical funding bodies also support the principles of the 3Rs in research involving animals. 

Scientific experts reviewing research applications are asked to consider issues such as whether the use of animals is justifiable, whether the use of a particular species is necessary, and whether the applicant has fully considered the 3Rs. These issues are also considered by the local ethical review process, which has been required by law since April 1999 in all establishments breeding, supplying and using animals.


The UK Government also plays a role in promoting the 3Rs. For example, it played a leading part in deleting OECD Guideline 401 (the so-called LD50 Test), a toxicity test, replacing it with a more humane alternative.

Other sectors

A variety of UK organisations, including research councils and charities, fund research that directly or indirectly contributes to replacement, refinement or reduction. See our 3Rs research funding page for details.

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