To find safe, effective natural insect repellents that are an alternative to DEET, you have to scratch below the surface. In addition to the usual greenwashing and other marketing hype, you'll find lots of conflicting information as well as some rather sketchy, fear-based "scientific reports."
There are two main types of repellents: conventional repellents containing synthetic chemical compounds, and "biopesticide" repellents that contain natural, plant-based compounds.
Of the four ingredients widely acknowledged as effective insect repellents, the first two are conventional repellents, and the last two are considered biopesticides:
- Lemon eucalyptus oil
There are also dozens of other plant-based oils that are touted as effective repellents (citronella oil, rosemary oil, cinnamon oil, etc.). Most studies have shown that these don't work well or need to be reapplied so often -- every 20 minutes in some cases -- that they're just not practical to use. You can sometimes find these plant-based oils added to repellents that contain other, more effective ingredients.
How Safe Are Conventional Insect Repellents?
DEET has been used by the general public as a bug repellent since 1957. As long as it's used as directed, DEET has been considered safe by groups like the American Academy of Pediatricians and the U.S. Centers for Disease Control and Prevention.
But the "use-as-directed" directions for use require that DEET be washed off the skin after coming indoors, as well as other specifics (don't get near mouth or on children's hands, etc.). There are reports of adverse reactions to DEET, including seizures and skin rashes, though these are rare. There is also some evidence that extensive, long-term exposure to DEET is associated with higher rates of insomnia, mood disorders and impaired cognitive function.
An August, 2009, study from France found that DEET may have a toxic effect on the nervous systems of mammals as well as insects. This disturbing discovery calls into question the presumed safety of DEET, the world's most widely used insect repellent.
Picaridin is another conventional insect repellent; after years of successful use in Europe and Australia, it was introduced into the U.S. in 2005. Highly effective and widely recognized as safe, picaridin is the active ingredient in Cutter Advanced Insect Repellent and Avon Skin-So-Soft Bug Guard Plus Picaridin.
Both picaridin and DEET are believed to have negligible effects on the natural environment. One advantage these two chemical compounds have over some plant-based insect repellents is their effectiveness at repelling ticks, including those that carry Lyme disease.
Biopesticide or Natural Insect Repellents
Biopesticide or natural insect repellents (sometimes called "botanical" or "plant-based") have been proven to be as effective as those containing synthetic chemical compounds like DEET. Remember, however, that "natural insect repellent" doesn't always mean safe, so you should use plant-based insect repellents as carefully as any other. Follow the instructions -- and your common sense -- when using any potentially harmful product, especially when children or pregnant women are involved.
Oil of lemon eucalyptus is a potent repellent, effective against mosquitoes, deer ticks and other pests. There's also a synthetic form of lemon eucalyptus oil known as PMD that's also effective. Both of these compounds are found in several brands of repellents that market themselves as natural. Parents should note that lemon eucalyptus oil is not considered safe for children under the age of three.
Though it sounds robotic, IR3535 is a plant-based compound that's been used in Europe for decades as an insect repellent. It works well against mosquitoes, biting flies and ticks, and is found in Avon Skin So Soft Plus IR3535 and other products.
DIY Natural Insect RepellentsIf you're determined to avoid any commercial repellent, you can try making your own at home. There are dozens of recipes for Do-It-Yourself insect repellents available on the Internet; most contain a base of alcohol or a "carrier oil," and one or more of the following ingredients:
- Cedarwood oil
- Tea tree oil
- Geranium oil
- Rosemary oil
- Lemongrass oil
- Citronella oil
- Eucalyptus oil
- Cinnamon oil
These might not be as long-lasting as commercial preparations, so plan on reapplying these repellents once or twice an hour. And be aware that people as well as insects can have a negative response to these oils -- skin rashes and other reactions have been known to occur.
Other Ways to Keep Bugs at Bay
Of course, there are plenty of non-chemical ways to avoid mosquitoes and other pests. Wearing long-sleeved shirts, pants instead of shorts, and shoes instead of sandals will thwart many bugs. Though these don't seem like great options in hot summer weather, thin, loose-fitting clothes are often just as comfortable and have the double benefit of helping you avoid sunburn and UV skin damage. Another sun-smart fashion tip -- a broad-brimmed hat -- works well at keeping bugs away from your head.
Try using a fan to ward off mosquitoes -- they can't stand a breeze -- and stay indoors during peak mosquito hours, usually twilight hours through early morning. Also, avoid using perfume, scented soaps or cologne, as these send out the "All You Can Eat Buffet" signal to mosquitoes and other biting insects -- even scented fabric softeners and dryer sheets have been implicated as bug magnets.