-  replacement, reduction and refinement

The 3Rs aim to replace the use of animals in scientific procedures with non-animal alternatives wherever possible, to reduce the number of animals used in experiments to a minimum and, in cases where animals do have to be used, to ensure that housing and procedures are refined to minimise the risk of any adverse impact on their welfare.

The concept was first developed by Prof. William Russell and Mr. Rex Burch at the Universities Federation for Animal Welfare in the 1950s

Please visit:  http://www.nc3rs.org.uk

                    http://www.ccac.ca/en/alternatives/index.html

a document for CUHK researchers => The severity of procedures and humane endpoints