DEET best, but not only viable mosquito repellent

By for CAES News

By Elmer Gray
University of Georgia

In mosquito repellents, the longtime standard DEET (N,N-diethyl-m-toluamide) is still the most effective. However, the Centers for Disease Control and Prevention recently added two new active ingredients to their guidelines.

The CDC now accepts picaridin, or KBR 3023, and p-menthane 3,8-diol (PMD), or oil of lemon eucalyptus, as viable alternatives for people who object to using DEET.

Both of these new active ingredients have been used in Europe and Australia for a few years. It should be noted that oil of lemon eucalyptus should not be used on children under age 3.

A word of caution about "natural" products: Often they're based on oils distilled and concentrated from plants. Usually these oils have evolved to help defend a plant from insect feeding. When they're concentrated and refined, they can be toxic and irritating. As a result, "natural" doesn't always mean "safe."

Safe for kids

Both the CDC and the American Academy of Pediatrics say repellents containing 10-percent and 30-percent DEET appear to be equally safe for children over 2 months old.

Parents should use lower concentrations on children if possible. At 10 percent, DEET is typically effective for 2 hours. At 30 percent, it's effective about 5 hours. Use higher concentrations (up to 30 percent for children) only when extended exposures are expected.

As with any repellent or insecticide, though, it's critical to read the label and apply only as directed. The most important aspect concerning children and repellents is for adults to apply whatever is used.

When applying repellents in general, apply them only to parts of the body that are exposed to mosquitoes. Don't apply any repellent to skin that will be covered by clothing. Don't apply a repellent to sunburned, irritated, cut or abraded skin, either, or to the mouth or eyes.

Be careful

When applying repellent to your face, put it on your hands and then rub it over your face. Use this technique on children in general. And after leaving the mosquito-infested area, wash all treated skin with warm, soapy water.

The risk of being bitten by a mosquito carrying a disease of any type is extremely small. But never underestimate the dangers of mosquito-borne diseases. Encephalitis (inflammation of the brain) is extremely serious and debilitating, no matter what version you get (West Nile virus, Eastern Equine, LaCrosse).

The best ways to limit exposure to mosquito populations are:

  • Wear light-colored, protective clothes.

  • Keep screens repaired.

  • Wear insect repellents when exposed to mosquitoes.

Eliminating all standing water around your home and neighborhood can greatly reduce the number of mosquitoes, too.

Using common sense, minimizing your exposure to mosquitoes, eliminating standing water and following label directions on repellents can help you have a safe and enjoyable summer.

(Elmer Gray is an Extension Service entomologist for the University of Georgia College of Agricultural and Environmental Sciences.)

Elmer Gray is a Cooperative Extension entomologist with the University of Georgia College of Agricultural and Environmental Sciences.