Some people take the view that all animal testing should be stopped immediately and replaced by in vitro alternatives or physicochemical methods. Unfortunately, that is not possible, in particular when a chemical or pharmaceutical is expected to affect one or more components of a biological system. In such cases, animal experiments will always remain necessary, but one may strive to reduce the number of animals and animal suffering. The internationally accepted basis in the search for alternatives to animal testing is the principle of the Three R's: replacement, reduction and refinement.
In 1954, the British Universities Federation for Animal Welfare commissioned a study on humane techniques in experiments with laboratory animals. The scientists Russell and Burch carried out the work and published their ideas in 1959 in their book 'The Principles of Humane Experimental Technique'. Among their ideas was the concept of the Three R's and the principle that the best criterion for choosing experiments to perform is the criterion of humanity. As so often happens with revolutionary ideas, the scientific and regulatory communities were slow to adopt the principles, although some critics were lavish in their praise:
"This deserves to become a classic for all time, and we have great hopes that it will inaugurate a new field of systematic study. We hope that others will follow up the lead it has given, and that a generalised study of humane technique, as a systematic component of the methodology of research, will come to be essential to the training of a biologist".C. Hume, Washington, 1959, on the launch of 'The Principles of Humane Experimental Technique'
The 1970s and 1980s were decades of increasing public concern about the use of animals, gradually resulting in a Three R definition of alternatives and national and European legislation incorporating the Three R's as the basis for fewer and better animal experiments.
"All procedures which can completely replace the need for animal experiments, reduce the number of animals required, or diminish the amount of pain or distress suffered by animals in meeting the essential needs of man and other animals".D. Smyth, in Alternatives to Animal Experiments, 1978