The 3R principles
The 3R principles are an external page ethical concept formulated in 1959 by British scientists William Russell and Rex Burch. The 3Rs stand for Replacement, Reduction and Refinement. They aim to minimise the use of animals in scientific experiments, maximise their well-being and promote alternative methods. ETH Zurich implements the 3R principles in animal testing and conducts research on the topic itself.
The 3R principles are recognised worldwide and have become part of the guidelines for conducting animal testing in many countries. They are an important part of ethical considerations and the assessment of research projects. By consistently applying the 3R principles, scientists ensure responsible treatment of animals and at the same time improve the quality and significance of their scientific results.
Replacement

The principle of replacement implies replacing animal experiments with alternative methods and models based on the latest scientific findings and technologies. New methods are being developed and applied in various departments at ETH Zurich that make it possible to answer fundamental scientific questions without the use of animal experiments. Such alternatives can in some cases completely replace animal experiments, for example, by using human tissues and cells, immortalis ed cell lines or computer models.
Reduction

Reduction refers to methods that reduce the number of animals required for an experiment without compromising the quality and reproducibility of the experiments. It’s crucial that animal experiments are appropriately designed and analysed in a way that they are reproducible and contribute to the expansion of knowledge. To achieve this goal, researchers at ETH Zurich can call on the advice of statisticians.
Refinement

Refinement refers to methods that reduce the strain on laboratory animals and enable them to have a better quality of life both during the experiments and throughout the entire husbandry period. This includes, for example, technologies that can minimise pain and stress in laboratory animals, as well as external page exemplary handling of the animals.
3R competence centres
Numerous national and international organisations offer information and support on the 3R principles:
- external page call_made Swiss 3R Competence Centre (3RCC)
- external page call_made National Centre for the Replacement, Refinement, and Reduction of Animals in Research, UK
- external page call_made 3Rs Centre Utrecht (3RCU)
- external page call_made The German Centre for the Protection of Laboratory Animals (Bf3R)
- external page call_made Norway's National Consensus Platform for the advancement of the 3Rs (Norecopa)
- external page call_made The Center for Alternatives to Animal Testing (CAAT) at Johns Hopkins University
- external page call_made Canadian Council on Animal Care (CCAC)