Dear EarthTalk: I can't seem to find any natural bug repellents that really work so I end up using the harsh, chemical varieties. Are there any really effective bug repellants that aren't chemically based, or other strategies we can use to keep bugs at bay?
-Melissa Armantine, New Paltz, NY
While the industry standard insect repellents rely on the insecticide DEET (N,N-Diethyl-meta-toluamide) to keep bugs at bay, many environmental and public health advocates worry that regular long-term exposure to even small amounts of the chemical can negatively affect the human nervous system.
The U.S. Environmental Protection Agency (EPA) reports that, in studies, DEET has been shown to be "of low acute toxicity," although it can irritate the eyes, mouth and skin. The EPA concluded after a comprehensive 1998 assessment that DEET does not present a health risk as long as consumers follow label directions and take proper precautions. And since nothing works quite as well as DEET in deterring disease-carrying ticks and mosquitoes, the Centers for Disease Control (CDC) is relatively bullish on its use in order to reduce incidences of Lyme disease, encephalitis and other insect-borne diseases.
Regardless, many consumers would prefer natural alternatives, and there are several companies already selling DEET-free insect repellents, many of which use essential oils as their active ingredients.
WebMD reports that soy-based repellent formulas (such as Bite Blocker for Kids) are the most effective substitutes for DEET, usually lasting for 90 minutes, which is longer than some low-concentration DEET formulas. Some other leading alternative repellents include All Terrain's Herbal Armor, Quantum Health's Buzz Away Extreme, Lakon Herbals Bygone Bugz, and California Baby's Natural Bug Blend Repellent.
WebMD adds that, despite popular opinion, products containing citronella are not the best non-chemical choice, as their effectiveness typically wanes within an hour. Likewise, peppermint oil and some other plant-based oils are also effective as insect repellents. Even venerable Avon Skin-So-Soft bath oil, long thought to deter pests as well as DEET, only keeps mosquitoes away for up to a half hour.
Beyond repellents, there are many other ways to keep pests away. For one, avoid floral fragrances from perfume, deodorant or other sources that can attract mosquitoes and other bugs.
The EarthEasy website recommends eliminating standing water around your home to keep mosquito breeding at bay. Bird baths, wading pools and pet water bowls should be changed at least twice a week; also make sure your gutters are draining properly. Also, since mosquitoes are attracted by carbon dioxide released from campfires and barbeque grills, EarthEasy recommends throwing sage or rosemary on the coals to repel mosquitoes.
If all else fails and DEET is your only option, use it sparingly. The American Academy of Pediatrics recommends using repellents with no more than a 30 percent concentration of DEET for kids over two-months old (and no repellent for younger babies).
Keep in mind that formulas with lower concentrations of DEET may work just as well as others but not for as long. A 10 percent DEET concentration, for instance, should work for up to two hours outside.
Applying DEET-based bug spray to your clothing instead of skin can help minimize any negative effects of exposure. Also, kids and grown-ups alike should wash off any DEET-based repellents when they are "out of the woods" so to speak.