Preparation of durable insect repellent cotton fabric through treatment with a finishing formulation containing cypermethrin

The efficacy and residual activity of cotton fabrics treated with a finishing formulation containing cypermethrin, a polymer and crosslinker, as per the fabrics using new impregnation as well as the polymer-coating techniques have been thoroughly evaluated. The remaining contact toxicities on treated fabrics before and after washing as well as storage were tested against mosquitoes. Insect repellency assays were conducted on treated samples and compared to control sample. Treated samples have shown excellent insect repelling efficiency. Bioassay results reveal that treated fabrics can be stored at room temperature (25 degrees C) for 18 months without loosing their efficacy. Also, bioassay results show that washing insecticide-treated fabrics do not substantially reduce the insecticidal effect after washings. Because of these attributes, cypermethrin is potentially a good candidate insecticide for treatment of mosquito nets. It is certain, however, that the coating technique is much more efficient than the impregnation technique.