This regulation establishes a tolerance for combined residues of avermectin B<INF>1</INF> and its delta-8,9-isomer in or on celeriac (roots and tops) at 0.05 parts per million (ppm). The Interregional Research Project Number 4 (IR-4) requested this tolerance under the Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection Act of 1996.