Should My Clothes Repel Insects?

A reader writes the Green Guide:

I received an email link from L.L. Bean about insect-repellent clothing. Have you done any research on this fabric treatment? I'm curious about what's involved in production and whether it does indeed work. (I have very tasty blood, apparently. Mosquitoes love me!)
Thanks,
Joanne

The Green Guide responds:

In 2003, the EPA approved Buzz Off Insect Shield "insect repellent apparel," which is now carried by many outdoor gear retailers, such as REI, L.L. Bean and Sierra Trading Post. The products are made effective by a powerful insecticide, yet even the clothing designed for children does not include warnings about the potential health risks and environmental impact from the active ingredient: permethrin.

Permethrin is a synthetic version of naturally occurring pyrethrin, a bug-killing chemical found in chrysanthemums. Synthetic permethrin is easily metabolized by many insects that may be effectively disabled by the chemical, but often recover. It can be highly toxic to fish and tadpoles, and in humans can cause asthma attacks, headache and nausea.

The information provided by the manufacturer contains no product safety disclosure, though some warning is certainly implied. Instead of making non-toxic claims, Buzz Off is characterized as odorless and colorless. The company's literature states that the insecticide is "tightly bonded to fabric fibers so that garments retain effective repellency" but also notes that after 70 washings the clothing is no longer protected. This means the active ingredient will come off the material, possibly while you're wearing it, especially after heavy perspiration. And research has shown that skin can absorb permethrin. Further, consumers are told not to wash the treated garments with other apparel, because "small amounts [of the active ingredient] can come off in the wash." All of this suggests the product could pose some health risk to consumers, but the garments come with no warning label.

Apart from the potential health risk, the product has limited impact. It will not protect exposed skin from insects, although you'll likely sustain fewer bites through your clothing. And while it may prevent ticks from crawling on your clothes and then on to you, the clothes won't keep ticks from jumping onto exposed heads, necks, arms or feet.

If you're truly worried about insect bites through clothing, you can apply a personal mosquito repellent to untreated clothes. For more tips on controlling mosquito populations around your home and for insect repellent product suggestions, see our Insect and Mosquito Repellents Buying Guide.