Five bug repellents scored high marks for preventing bites, but three common choices didn’t make the grade in 2014 testing by Consumer Reports. As a parent and pediatrician, I want a mosquito and tick repellent that is safe, effective, and easy to use. It also helps if it doesn’t smell like bug spray.
Why Is Blocking Mosquitoes and Ticks Important?
Insect and arachnid bites aren’t just annoying; they are also the cause of hundreds of West Nile virus infections, about 1500 cases of malaria, and about 35,000 cases of Lyme disease diagnosed in the US each year – not to mention the million people who die from malaria each year around the world. Even though most mosquito bites are just an itchy nuisance and most tick bites are barely noticed, it’s important to have a reliable way to block bites when needed.
Repellent testing involves daring testers who put their bare arms in mosquito-filled cages and who let ticks crawl on them, while observers record how long it takes the critters to start biting. The top five products prevented bites from ticks and two important species of mosquitoes for at least seven to eight hours of the test. In four of these winners, the active ingredient was DEET::
- Off Deep Woods Sportsmen II (DEET 30%)
- Cutter Backwoods Unscented (DEET 23%)
- Off FamilyCare Smooth and Dry (DEET 15%)
- 3M Ultrathon Insect Repellent 8 (DEET 25%)
- Natrapel 8 Hour (picardin 20%)
Repel Plant-Based Lemon Eucalyptus Insect Repellent was included in the 2010 list of recommended repellents, but it was omitted from the 2014 list because the reformulated product has less of the active ingredient, and has not been retested.
All of the above repellents use active ingredients registered with the EPA and included in the CDC recommendations for preventing diseases spread by insect bites.
Other products tested had some benefit, but scored much lower overall:
- Bite Blocker Xtreme (Plant Oils)
- Cutter Skinsations Clean Fresh Scent (DEET 7%)
- Burt’s Bees All Natural Herbal (Plant Oils)
How Safe Are the Top Repellents?
The EPA rates DEET as Category III (slightly toxic) for acute oral or dermal exposures. DEET is irritating to the eyes and mucous membranes. Skin rashes are the most frequent side effect but are uncommon. Suspected serious adverse reactions are rare, but include seizures and encephalopathy in children. DEET is considered slightly toxic to birds, fish, and aquatic invertebrates. The EPA says that child safety claims on some DEET products are misleading and not allowed because concentrations lower than 30% are not known to be any safer. Because the risks are well understood, DEET is recommended by the CDC and AAP for use on babies down to 2 months old, but is not considered safe for newborns.
Likewise, the EPA considers picaridin Category III (slightly toxic) for acute oral or dermal exposures. In animal studies, it caused slight to minimal liver hypertrophy, individual necrotic liver cells, chronic kidney inflammation, and slight kidney degeneration when ongoing large amounts of picaridin were applied to the skin. They found no evidence that it is an endocrine disruptor or carcinogen. It is nontoxic to birds and moderately toxic to fish.
I prefer the plant-based oil of lemon eucalyptus. No adverse effects have been found, other than eye irritation. The EPA considers it Category IV (practically non-toxic), for acute oral or dermal exposures – indeed for any route except being splashed in the eyes (so use lotion or use spray in the palm to apply to face). They’ve determined that it poses minimal or no risk to wildlife and is not harmful to the environment. The EPA assessment concludes that it is not expected to pose health risks to people, including children, pregnant women, or other sensitive populations. Nevertheless, the official recommendation is not to use it on children younger than 3 years because testing has not yet been done on young children.