New Use Restricitons and Standard Operating Procedures for Rotenone and Antimycin

The piscicides rotenone and antimycin have recently been cleared by the U.S. Environmental Protection Agency for reregistration under the Federal Insecticide, Fungicide and Rodenticide Act.  Human health and environmental risk assessments on the piscicides completed by the agency resulted in new restrictions placed on their use designed to minimize nontarget exposure to the public, applicators and environment.  Maximum use rates have been reduced to 200 ppb rotenone and 25 ppb antimycin for both standing and flowing waters, and deactivation with potassium permanganate is now required when discharging into untreated flowing waters.   Their use in marine/estuarine waters is now prohibited, and treatment areas must be placarded during the reentry intervals.  Personal protective equipment must be worn when entering the treatment areas during the reentry intervals which begin with the piscicide application may last up to 14 days.  Monitoring of piscicide residues and notification of affected parties are now required when treating waters used for drinking.  Semi-closed probe/aspirator systems are now required for treatment of most large standing waters with rotenone, and surviving fish treated with antimycin cannot be consumed for 12 months.  As a condition of reregistration, these changes have been incorporated into standard operations procedures manuals.