and Rinehart, 1979) did note an effect on testis weight and testicular hypoplasia at doses of 500 and 2,000 ppm (75 and 300 mg/kg per day; NOAEL of 20 ppm or 3 mg/kg per day). There was also increased mortality at the two higher doses. However, no such effects in rats or mice were noted by Ishmael and Litchfield (1988) using concentrations of permethrin up to 2,500 ppm in feed. The Life Science Research (1980) study also reported no effects of permethrin in rats on testis weight or histopathology at doses of up to 250 mg/kg per day. Thus, information on male reproductive effects is minimal at best, and the most conservative NOAEL was 3 mg/kg per day.

The NOAEL of 3 mg/kg per day based on testicular effects and the daily intake of 6.8 × 10−5 mg/kg per day from wearing permethrin-impregnated BDUs provide a MOS of approximately 44,000.

Because the daily lifetime dose for garment workers is less than that for military personnel (3 × 10−5 mg/kg per day), the MOS for garment workers is 100,000.

Given the lack of reproductive or other types of toxicity (except for the liver) in most of the reproductive and developmental toxicity studies available on permethrin and a MOS of approximately 44,000 or more from the most sensitive toxic end point (decreased testicular weight), the possibility of male reproductive effects or other reproductive and development effects occurring from wearing permethrin-impregnated BDUs or working with treated fabric seems remote. It should be noted, however, that no data are available from dermal exposure studies. Furthermore, there is disagreement among different studies on the doses at which toxicity was observed, and there are no specific studies on either male reproductive effects or human reproductive toxicity.

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