The 3-R principle: Reduction, Refinement and Replacement (3-R principle)

If animal testing is carried out, it is done in a responsible manner. This means that we strive for ‘Reduction’, ‘Refinement’ and ‘Replacement’, the so-called 3Rs (drawn up by the Central Committee on Animal Experiments on behalf of the national government):

1. Reduction: this entails the reduction of the number of animals used in a project or experiment, wherever possible
2. Refinement: these are the use of methods which minimise animal suffering and improve their welfare, for example, testing animals in their homecage environment to prevent unnecessary stress
3. Replacement: this is the replacement of the animal by an alternative, such as organoids, cell cultures, and so forth.

In sum, this principle entails that when possible, the use of animals is limited to the absolute minimum, in such a way that the suffering of the animal is kept at a minimum, and that replacements for the animal model are used when available.