How does bug-repellent clothing work?

In 2003, after seven years of research and development, a company based in North Carolina received approval from the Environmental Protection Agency (EPA) to begin selling its line of "Buzz Off" clothing. The company branded its new technology as "insect shield," and it's effective at warding off a plethora of bugs, including mosquitoes and ticks.

The secret to insect shield is the use of permethrin, a synthetic version of a naturally occurring chemical called pyrethrum, which is found in chrysanthemum flowers. Chrysanthemums are known as a good natural deterrent to pesky insects. Permethrin is a "knockdown" insecticide, meaning it disables the insect when they come in contact with it. So it doesn't so much repel the insects as knock them out or kill them.

How insect shield actually works is a bit of a mystery -- or more like a trade secret. But we do know that permethrin is actually woven into the fibers of the clothing fabric. Since a mosquito is able to insert it's proboscis through most clothing, then warding them off your t-shirt is a good idea. It's odorless and isn't readily absorbed into the skin, so it's safe for adults and children. Do you need to walk around smelling bad because you're afraid to wash your $50 Buzz Off pullover? Not at all -- the new line of insect shield clothing can stand up to 70 washings and maintain effectiveness.

The technology works on most any fabric as long as you don't have the garments dry-cleaned. You can buy the goods online from a variety of outdoor gear Web sites, and you have a plethora of duds to choose from. Most of the garments are suited for the outdoor enthusiast -- pullovers, cargo pants, bandanas, hoodies and fishing vests. They also offer visors, floppy hats and a line of kid's clothing. You won't know any difference between clothes treated with permethrin and regular clothes either, aside from being bug-free. The U.S. Army uses insect shield, but it's not been shown to reduce the number of mosquito-born illnesses.

The clothing has been shown to be fairly effective at warding off insects where your skin isn't covered with the clothing as well. So if you have on a short-sleeved insect shield shirt and a hat, you'll get good coverage for your arms and neck as well. If you want to use a little DEET on your exposed skin too, you can almost guarantee an insect-free experience. How much do these clothes cost? Not a whole lot more than your standard outdoor gear, which isn't too cheap to begin with. Plan on adding about $10 for pants and shirts and three to four bucks for hats and bandanas.

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