Statistics and the LD50 Study

An increasing concern over the LD50 study has become apparent over the years and even more so recently in Britain with the Home Office Publication on the subject and comments and opinions expressed in the National Press. Particularly with respect to the Pharmaceutical and Agrochemical Industries, the number of animals used depends on the number required to satisfy the Regulatory Authorities. Is there a scientific rationale for using the number of animals required? Data is presented justifying the use of smaller numbers of animals for establishing the acute toxicity of a chemical.