EPA is redesignating certain pesticide data requirements currently located in 40 CFR part 158 into a new part 161. The data requirements being transferred apply to antimicrobial pesticides. EPA is also making conforming changes and cross-reference revisions to the newly redesignated material. The redesignation is intended to preserve regulatory data requirements for antimicrobial pesticides, while preparing for the promulgation of final rules pertaining to data requirements for conventional pesticides, biochemical, and microbial pesticides.