Wildlife Damage Management, Internet Center for


Date of this Version

February 1978


Published in Proceedings of the Second Eastern Pine and Meadow Vole Symposium, Beltsville, Maryland, February 23-24, 1978, Ross E. Byers, editor. Copyright © 1978 Kaukeinen.


In the Proceedings of the first Eastern Pine and Meadow Vole Symposium (March 1977, Winchester VA), ICI was introduced and basic technical information on PP581 presented. PP581 is a second-generation anticoagulant rodenticide, with the approved common chemical name of brodifacoum. The compound is also known as TALON™ in the form of 50 ppm (0.005%) grain-base pelletized bait as developed for control of commensal rodents. The proposed trade name for the orchard formulation of PP581 is VOLAK™. Brodifacoum has been seen to possess several novel characteristics in work with commensal and other rodent species, suggesting a considerable general potential for control of many pest species of rodents and in various use situations. These characteristics are:

1. Single-feeding action for most species. (Defined as giving over 90% control in 1 day no-choice or 3 day choice tests with 50 ppm bait)
2. Effective on anticoagulant resistant rodents. (As based on US and UK lab studies with warfarin-and cross-resistant rats and mice which were successfully killed by PP581)
3. No bait avoidance.(Beyond that avoidance shown by rodents to any new object or foodstuff, bait avoidance is not a factor and bait is well accepted by most rodents. The lapse of several days till death reduces the chance of rodents associating bait ingestion with poisoning symptoms.
4. Antidotable.(Vitamin K1 injections are antidotal, as is the case for existing anticoagulant products)
5. Low hazard. (PP581 baits at 50 ppm should be as safe to most non-target animals and the environment as other antlcoagulants in current use)