If you’re worried about the Zika virus (and according to the Centers for Disease Control and Prevention, you have reason to be), you should stop worrying about DEET. Even on infants older than 2 months. And especially if you’re pregnant. In fact, even though DEET hasn’t been tested on pregnant women in their first trimester, experts are now saying that it’s okay for all pregnant women to use insect repellents that contain DEET, since the danger of Zika to an unborn baby is higher than any potential danger from DEET.Poor DEET—nobody wants to invite it to their birthday party. And that’s very sad, because DEET is the most tested insect repellent available on the market. “Concerns over the safety of DEET first emerged during the 1980s after reports of encephalopathy following DEET exposure, particularly in children. However, the role of DEET in either the illness or deaths was and remains purely speculative,” says this recent meta-study on the safety of DEET.
That sentiment is echoed in this 2015 paper (subscription required) on insect repellent: “During the 1980s and 1990s there were several reports of encephalopathy following DEET exposure in children. However, risk assessments by both the US Environmental Protection Agency (USEPA) and independent publications, as well as a clinical trial, found no association between encephalopathy and DEET use, and no toxological risk or severe effects except after inappropriate use (ingestion, direct inhalation, or eye exposure).”
The Division of Toxicology and Human Health Sciences looked into the health effects of DEET, as well, and found that over 40 years of use, from 1961 to 2002, eight DEET-related deaths occurred. Three were of people intentionally drinking it, two were of adults wearing it, and three were of girls under 6 who underwent “heavy” use. One of those girls had a health condition that may have contributed to her death.
|Repellent||Use||Safe for babies (2 months to 3 years)1||Safe for kids (3 years and up)||Safe for pregnant people|
|Oil of lemon eucalyptus||Skin and clothes||No||Yes, animal tested||Yes, animal tested|
|Picaridin||Skin and clothes||No||Yes, animal tested||Yes, animal tested|
|IR-3535||Skin and clothes||Yes, adult tested||Yes, adult tested||Yes, adult tested|
|DEET||Skin and clothes||Yes, infant tested2||Yes, kid tested2||Yes, tested with pregnant people2|
That being said, DEET is the safest bug repellent out there, according to both the CDC (PDF) and the EPA. It’s also one of the few okayed for use on babies as young as 2 months, and on pregnant women in their second and third trimesters.
Because people are worried about this type of thing, most bottles of DEET tell you to wash it off after use. This step is to minimize your exposure, said Dr. Mark Fradin, a dermatologist who co-authored one of the seminal papers on the efficacy of mosquito repellents, in an interview. But DEET is “a remarkably safe product when used intelligently.” So follow those rules on the can.
The alternatives aren’t necessarily safer. Picaridin hasn’t been safety-tested nearly as much as DEET, though it may be just as effective. Oil of lemon eucalyptus is most often a synthesized, lab-made compound also known as PMD. According to the CDC, neither type is suitable for use on kids younger than 3, because they are severe eye irritants and kids that little tend to rub their eyes a lot. And PMD is not the same as the “pure” oil of lemon eucalyptus, which is not recommended for use as a repellent as it hasn’t been tested for efficacy.
As for other options, according to the study that Fradin co-authored, so-called “natural” repellents don’t work nearly as well. We wouldn’t trust them to prevent mosquito bites.
For more information on alternative bug repellents, the best DEET concentration, and details about Zika, read our recommendation for the best bug repellent.
When a source of light moves toward you, its waves are compressed and pushed to a higher energy. We can’t always see this blue shift, but it’s there.
In the space of Internet science, there’s a lot of bad information floating around. In this biweekly column, Leigh Krietsch Boerner, chemistry PhD and science editor of The Sweethome, will tell you what you need to know on the science of home products, and what’s all around you.
(Top photo by Michael Hession, with illustration by Elizabeth Brown.)