Initiatives to decrease redundancy in animal testing of pesticides.

Two well-documented examples of studies that can be eliminated from the data requirement list without apparent impact on the quality of risk assessment are presented. Database evaluations demonstrated no clear difference in sensitivity between 3-month and 12-month dog studies. From a regulatory perspective, only two compounds were identified in which the NOAEL for the 12-month dog study was more than 2-fold lower than in any other study. Evaluation of the contribution of the mouse cancer study demonstrated that in 5% of all cases the mouse cancer study was used for reference dose setting and in 1.5% it was used for selective cancer classification. It is suggested that regulatory agencies periodically review their study requirements for redundant studies.