Comment submitted by Changlu Wang, Rutgers University

Benefit of registering propoxur: may help slow down insecticide resistance management because it has different mode of action than pyrethroids. Potential adverse effect of using propoxur: It may pose similar or lightly greater environmental and health risk than pyrethroids. It is no more toxic to human than lamda-cyhalothrin (a registered pyrethroid for bed bug control) based on oral and dermal LD50 values. I think approving propoxure for bed bug control may have limited benefits because: 1. Bed bugs develop resistance to insecticides rapidly. All pyrethroids and carbamates are subject to control failure due to bed bug resistance development. 2. Lily et al. (2009) compared the toxicity of carbamate, organophosphate, pyrethrin, and pyrethroid insecticides against bed bugs. Carbamates were not superior to pyrethroids. 3. Propoxur is unlikely to significantly improve the efficacy, even it has significantly higher toxicity against bed bugs than pyrethroids. This prediction is based on the bed bug behavior which allows them to hide in areas where pesticides are difficult to apply or can not be applied (such mattresses, boxsprings, sofas). EPA should first grant an experimental use permit. After obtaining sufficient data, then a decision can be made.