It seems no summer cookout is complete without mosquitos ― and an insect repellant to keep those uninvited, pesky guests away. Most repellants contain an active ingredient called N,N-Diethyltoluamide, or DEET, which is effective at protecting against mosquito bites. According to Consumer Reports, DEET is the most widely used insect repellant in the United States. But despite its popularity, it has a pretty bad reputation for being a toxic chemical.
A 2015 Consumer Reports survey revealed that only one-third of 2,011 respondents believed the insect repellant products on the market were safe for adults. Some of the reasons for the skepticism about DEET come from reports of it causing adverse skin reactions and seizures in children. There are also fears it causes cancer.
So, how safe is that repellant you’re using? Should you REALLY be concerned? Here’s what experts want you to know:
First, the deets on DEET
DEET was originally developed by the United States Army in 1946 to protect soldiers in areas infested with insects. In 1957, it was released to the general public in the U.S. for use in commercial insect repellants. As with the active ingredients in sunscreen, DEET becomes effective once applied on the skin, acting as a barrier between you and those biting bugs.
A common misconception about DEET is that it kills mosquitos. In reality, DEET doesn’t kill the bugs, but instead interferes with the receptors they use to detect human chemicals that attract them, preventing them from biting you, according to OFF, a well-known insect repellant brand.
Is the product really dangerous?
The simple answer is no. (Phew.) But there is a slight caveat.
Dr. Joyce Davis, a board-certified dermatologist in private practice in New York, noted that it can become unsafe if you don’t apply it properly or if you apply a higher concentration of it than necessary. The concentration of DEET tells you how long the repellant will protect you from insects, Davis explained. You can check the concentration amount by looking for the percentage on the front of the bottle or can.
“To prevent overexposure, children should only use insect repellants with a DEET concentration of 15 percent, and adults should use repellants that don’t exceed 30 percent,” Davis said.
The Environmental Protection Agency periodically checks DEET for new potential health hazards. Bryon Backenson, deputy director for disease control at the New York State Department of Health, said the EPA re-registers products, including DEET, at regular intervals over time to check for new scientific evidence, reports of toxicity or negative effects.
According to the EPA’s website, DEET was approved for re-registration in 2014, and was not identified as having any risks of concern to human health. There is also no known evidence that DEET does or does not cause cancer.
Some of the more alarming reports about the dangers of DEET focus on its effects on pregnant women and their babies, but studies about its effects on pregnancy have been largely done using rats. Consumer Reports reported on a 1994 study that showed when pregnant rats were exposed to high doses of DEET, their offspring had low birth weights. But for humans, there hasn’t been a large amount of supporting data that shows DEET is bad for pregnant women.
In fact, according to the pregnancy site What To Expect, the best way for pregnant women to prevent mosquito bites is to use mosquito repellant that contains DEET, which is the most effective type of spray against mosquitos. (This is especially useful when it comes to protecting yourself in areas with a history of Zika, a mosquito-borne illness known to cause birth defects.)
How to safely use DEET
The best way to safely use DEET is pretty simple: Follow the directions as listed on the product label.
“You should really read the label,” Backenson said. “They’re not the most user-friendly and the writing is tiny, but people should still read them.” This includes looking for age restrictions (the U.S. Center for Disease Control and Prevention recommends DEET for ages 2 months and up), concentrations and how long you’ll be protected while using the product, Backenson added.
Davis said applying DEET products on children should only be done by adults who put it on their own hands first. “I recommend that adults apply it to the child’s face because we don’t want it sprayed on children’s hands as they tend to put their hands in their mouth,” Davis said.
According to Davis, regardless of age, anyone who applies repellant that contains DEET should only spray it on exposed skin and not under clothing, and you should avoid spraying on or near openings like your ears, mouth and eyes. And when you go back indoors, it’s important that you wash off the areas you applied DEET to keep from unintentionally prolonging your skin’s exposure to it.
What about going the natural route for your insect repellant?
Natural alternatives to DEET include citronella and oil of lemon eucalyptus, but experts stressed that neither are as effective as DEET.
“DEET has low toxicity, so the additional ‘safety’ factor of natural repellents is probably small,” said Dr. Jeffrey Bloomquist, a professor in the department of entomology and nematology at the University of Florida.
Backenson added that there are four active ingredients the EPA and CDC recommend that are effective at repelling insects: DEET, picaridin, IR3535 and oil of lemon eucalyptus. So, some natural products may help if you prefer that route, but be warned: “All-natural doesn’t always mean safe and effective,” Backenson said.
Other forms of protection, such as repellant wristbands and anti-mosquito cell phone apps, don’t really work or will only be effective for about five minutes, Backenson said.
However, despite the differences in effectiveness of the various types of repellants, Backenson said it’s ultimately up to each individual to assess what scents they can tolerate and which products give their skin a negative reaction. So if DEET isn’t your deal, that’s fine. Just make sure you take some expert-backed precautions ― and talk to your doctor if you feel your bug bite needs medical attention.