Pyrethroid dips

The impact of pesticides on water quality in organic systems has rarely been studied (Stock-dale et al. 2001). Again, however, most of the water contamination comes from herbicides used in conventional farming. There is some debate about the disposal of sheep dip and the relative risks of pyrethroids versus organophosphates. Organic farmers only use the former and they are potentially more damaging to aquatic habitats. 

The persistent pyrethroids such as permethrin, cypermethrin, cyfluthrin, and fenvalerate are effective mothproofing agents when applied as spot treatments from ready to use (RTU) formulations. Sodium fluosilicate [16893-85-9] is an effective mothproofing agent used at 0.5 to 0.7% in water solution with 0.3% potassium aluminate and 0.03% oxalic acid, and applied to fabrics by spraying or dipping. It is not removed by dry cleaning. 

The numbers of environmental incidents are shown in Table 16.1. The vast majority of these involved the deaths of aquatic vertebrates and fish, frequently because of contamination of water courses with sheep dip formulations. The ingredients in these are synthetic pyrethroids (e.g. cypermethrin) and, to a lesser extent, organophosphorus compounds, notably diazinon. The remaining incidents involved poisoning in birds of prey, possibly deliberately. ... 

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