Rodenticide Label Changes Impact Food Industry Rodent Management

Rodenticide labels are transitioning to new language that will limit usage to within 50 feet of buildings to help mitigate non-target animal hazards. This will effectively eliminate much of the fence-line baiting which has been a component of the current “three lines of defense” strategy, and will mean that sanitation, rodent proofing, harborage elimination, and more intensive tactics at the building perimeters will need to be stepped up.

The label changes are part of EPA’s Final Risk Mitigation Decision for Ten Rodenticides published in 2008 with full implementation of the risk mitigation measures and new labeling mandated by June 2011. The ten rodenticide active ingredients are brodifacoum, bromadiolone, bromethalin, chlorophacinone, cholecalciferol, difenacoum, difethialone, diphacinone, warfarin and zinc phosphide.

Some of the new restrictions that will affect pest management operations in the food industry include:

• Bait placements must be within 50 feet of buildings.
• Bait placements are limited to around industrial buildings and similar man-made structures, agricultural buildings, warehouses, food storage buildings, port and terminal buildings, and in alleys.
• Target rodents are explicitly limited to house mice, Norway rats, and roof rats only.
• Bait placements are limited to outdoors in secure, tamper-proof bait stations. This point is not new for food plants, as industry sanitation standards have limited rodenticide placement more than rodenticide labels for years, essentially prohibiting indoor baiting except for very tightly controlled, temporary situations.

Questions of Interpretation. There are some question of interpretation as labels are not completely clear on the legality of baiting in certain situations of legitimate need in the food industry. State regulatory agencies have the responsibility of interpreting labels and have a history of interpreting labels differently. However, corporate or food safety audit standards tend to work best when a simple standard can be applied uniformly. New label language and uncertainty over acceptable rodent management techniques will be issues in the food industry until the regulatory and auditing communities settle into new standards.

Practical Recommendations. A facility with deficiencies in exclusion and sanitation was never being saved by fenceline bait stations. However, without this defense, it can be expected that more rodents will approach building perimeters. Recommendations for stepping up remaining defense tactics include:

• Buy some time. Rodenticide products without the placement restrictions could remain in channels of trade for some time, so drastic changes need not be implemented immediately. Rather develop a plan. make improvements, and conduct periodic facility assessments, such as those required by AIB or BRC sanitation standards.
• Harborage Elimination: Eliminate potential harborage areas in and around your plant, and, if necessary, make arrangements to cross the line and clean up a harborage on your neighbor’s property. Inspect your landscaping and consider taking out the overgrown bushes, trees, ground covers and mulched beds that are being cultivated as harborages.
• Tactics at the building perimeter: Use the best bait you know for maximum effect. Where needed, increase the number of bait stations or supplement stations with outdoor trapping.
• Use traps at the fenceline instead of bait: Several models of snap traps are available that will fit into bait stations and that feature safe, fast and easy protocols for setting. Trapping also serves a monitoring function.
• Rodent proofing: Fix the small gaps as well as the often overlooked broken doors, big gaps at thresholds, or gaps where overhead doors meet the floor, not to mention other openings into buildings. Not unexpectedly, most rodent captures in food plants are near openings.
• Sanitation: The need for enhanced rodent management may be the extra incentive necessary to improve outdoor spillage cleanup, garbage handling practices, and policing of litter and debris.