is done as a check on the safety of new drugs or substances for
human or animal use, and to check whether new batches of drugs and other agents
such as vaccines work. There is a legal requirement to test how safe and effective
chemicals, drugs and other therapeutic agents are before they can be sold. Well-known
tests that cause suffering when the test substance is poisonous, corrosive or
otherwise harmful are the LD50 Test and the Draize Eye Irritancy Test. All three of the Three
Rs have been successfully applied to testing and scientists are working
hard to find more and better ways of applying them. For instance, replacement
of animals with tissue cultures (cells kept alive in a test tube) is now used
extensively, especially in the early stages of testing when whole animals were
once used. Also, employing careful statistical analysis and substitutes for animals
(replacements) have markedly reduced the number of animals required in testing procedures,
and using earlier more humane endpoints thereby ending a noxious testing procedure
much sooner than used to be the case is a form of refinement.
