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Open Access Publications from the University of California

The rationale for requiring Bitrex and dyes in rodent baits


In 1998, the Environmental Protection Agency issued Reregistration Eligibility Decisions for the rodenticides Brodifacoum, Bromethalin, Bromadiolone, Chlorophacinone, Diphacinone, Pival, and Zinc Phosphide. These decisions imposed requirements that bait products containing these ingredients and marketed for control of commensal rodents also contain an "indicator dye" and a "bittering agent." The indicator dye would be used to mark children who come in contact with bait. The bittering agent would be used to render a bait unpalatable to children, possibly reducing the amount of bait eaten. This paper discusses these requirements and other regulatory attempts to limit risks of rodenticide baits to children and nontarget animals. EPA is reconsidering the requirements for the indicator dye and bittering agent. Currently, either type of agent may be added to a bait product voluntarily if the new bait can pass required efficacy tests.

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