Effects of Laundering on the Permethrin Content of Impregnated Military Fabrics

摘要

The insecticide permethrin, when impregnated into the military Battle Dress Uniform (BDU), is remarkably effective in repelling bites from disease bearing insects. In practice, however, both wear and laundering will likely affect the insecticidal level within the BDU cloth and may alter the leaching rate of permethrin out of the fabric. To address these issues, both cotton and NYCO (50/50 nylon-cotton) BDU fabrics were impregnated with c14 labeled permethrin, then laundered 1 to 10 times. Permethrin loss was measured by chemical and by radiochemical analysis. Swatches (50 sq cm) of each fabric, washed 1, 5, or 10 times, were affixed to the backs of rabbits and worn continuously for 7 days to quantitate permethrin migration to the skin. The results indicated that after 10 washings, permethrin loss measured 40 percent from cotton fabric and 55 percent from NYCO. The greatest loss (20-30 percent) occurred during the first wash. The rate of permethrin leaching from either type BDU cloth being worn by rabbits was unaffected by the number of launderings. In all cases, 3-4 percent of the impregnant reached the skin surface of rabbits through 7 days. (sdw)