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Is DEET safe? New insect repellent study offers surprising insight

Who would’ve thought bug spray could repel people, too?

That’s what’s happening with DEET, that much-maligned ingredient found in insect repellents with tough-sounding names like “Deep Woods” and “Sportsmen.” While some Scouts and Scouters swear by the stuff, others have sworn it off completely.

Who’s right? A recent study from the Environmental Working Group aims to answer that question once and for all.

Turns out DEET (or N,N-diethyl-meta-toluamide if you’re looking to impress friends) has a safety profile that’s better than many people assume. “Its effectiveness at preventing bites is approached by only a few other repellent ingredients,” the study suggests.

On the plus side, if used as directed, DEET is considered safe by many public health organizations, including the Environmental Protection Agency, the Centers for Disease Control, the American Academy of Pediatrics and World Health Organization (AAP 2005, CDC 2013D, EPA 1998, Schutze 2013, WHO 2012). DEET is among those chemicals recommended by WHO for protection against disease-carrying mosquitoes and is the only repellent recommended by the CDC to protect against Lyme disease (CDC 2013D, WHO 2012).

Like any chemicals you’d put on or in your body, the key is reading and following the directions. For example, the Environmental Working Group (EWG) doesn’t recommend using sprays with more than 30 percent DEET on anyone. And certain chemicals aren’t safe to use on children.

Whenever you press down on the spray-bottle trigger, you’re making a choice between the harms caused by bug bites and the potential harms from the spray itself. Last year, 286 Americans died from exposure to West Nile Virus, carried by mosquitos. And ticks carrying Lyme disease affected 24,364 people in 2011.

With those sobering numbers in mind, EWG writes: “DEET isn’t a perfect choice nor the only choice. But weighed against the consequences of Lyme disease and West Nile virus, we believe it is a reasonable one.”

The four best ingredients

But there’s more out there than just DEET. The four repellent ingredients that EWG found to be top picks are:

  • Picaridin: Safer than DEET and odorless but a shorter protection time
  • IR3535: Good safety profile but can irritate eyes and melt some plastics
  • DEET: Very effective and widely used but should be limited in use on children
  • Oil of Lemon Eucalyptus and its synthetic derivative PMD: Most effective botanical ingredient but not for children 3 and under and can irritate lungs

For the full guide and pros and cons, go here.

Repellents to avoid

Bug zappers, yard bug treatments, clip-on repellents, candles and pure essential oils were all deemed unsafe or ineffective by EWG.

You tell me

Which kind of bug spray or insect-repelling techniques does your Scout unit use?


Photo: Some rights reserved by Spokenhope | H/T to Scott F. for the post idea

29 Comments on Is DEET safe? New insect repellent study offers surprising insight

  1. I prefer the Ultrathon, thick lotion and stays effective a lot longer than Deep Woods OFF! Used it in the BWCAW on Northern Tier this past June and it was like the skeeters left after putting it on!

  2. Karen Zeller // July 31, 2013 at 12:14 pm // Reply

    I use DEET regularly. But I don’t have to use as much of it when I zip the Scout pant legs back on and wear a hat — good deterrents to ticks, biting flies, and mosquitoes.

    • Gary Wilson // August 1, 2013 at 2:46 pm // Reply

      Concur. Mosquitoes are mostly a nighttime problem, so long sleeves and pants reduce your target area. A broad-brimmed hat also works well at keeping Gnats above your head.

  3. I do use a 26% DEET spray on clothing but try to limit the exposure on direct skin.

    Bryan, it says Deet “should be limited in use on children”. What age children? Are we talking about 3 and under or 12 and under? Big difference! (We have to keep in mind that even sunscreen has limited recommendations for young children).

    • John Pinchot // July 31, 2013 at 12:28 pm // Reply

      The current AAP and CDC recommendation for children older than 2 months of age is to use 10% to 30% DEET. DEET should not be used on children younger than 2 months of age.

    • Good question, Angel. This is from the study:

      0 to 6 months: No DEET
      6 to 24 months: Only when bug risks are high, 5-10% DEET products, Limit to 1 application per day
      2 to 12 years: 5-10% DEET, Limit to 3 applications per day, Avoid prolonged use
      General population: No more than 30% DEET allowed in products

  4. John Pinchot // July 31, 2013 at 12:23 pm // Reply

    So Picaridin (Natrapel) is as effective as DEET but is not a neurotoxin and does not melt plastic. How could putting a substance that melts plastic be good to put on your skin.

  5. I’ve been using the 20% Picaridin for the last few years and it seems to work as well as DEET. The nice thing is that doesn’t melt the synthetics like DEET does. Some of us have tried using the ThermaCell personal area protection device. It seems to work as well if you aren’t moving around and there is little air movement, like around a campfire. I wouldn’t necessarily recommend these to younger scouts because it heats up. One thing I would not recommend is the use of Permethrin. Permethrin is an insecticide not a repellant. It is also highly toxic to aquatic life. May be great to use by military sorts, but I’d rather not put it near the skin of young’n.

  6. Jason Bostick // July 31, 2013 at 12:51 pm // Reply

    is DEET damaging to clothing?

    • From EWG: “DEET gives off a distinct odor and can damage plastic, rubber and vinyl on a variety of gear including clothing, backpacks, glasses, watches and cameras (Schutze 2013).” So I would certainly test it out on a small, non-visible area of your clothing before spraying it everywhere.

      • Gary Wilson // August 1, 2013 at 2:55 pm // Reply

        In the service in the 1970’s, we were issued 100% DEET to avoid carrying around the useless weight of the inert ingredients. It actually was invented for use in Vietnam.

        Now there’s nothing wrong with that strength as long as you use it very sparingly; 1/3 of what others might douse themselves with. You’re basically creating an odor shield around you to upset the mosquitoes nervous system on final approach; you don’t need a drop of DEET on every square inch of exposed skin to create that airborne cloud.

        However 100 percent DEET will melt plastics to some extent. A buddy of mine wound up fogging the plastic crystal of his wristwatch with it.

  7. We use 20 – 30% deet on skin and permethrin on clothes. Keeps the ticks and skeeters off in Florida.

    • Brian wrote: “We use 20 – 30% deet on skin and permethrin on clothes. Keeps the ticks and skeeters off in Florida.” That’s good advice in Pennsylvania also.

      Permethrin is the best product for preventing tick bites. But, it must be applied to your clothing. It does absolutely no good if applied to your skin. What is truly amazing is that it remains effective even after treated clothing is washed 5 or 6 times. It doesn’t repel ticks and mosquitoes, but instead kills them.

      You can even buy clothing that has been treated with permethrin, but it is very easy for anyone to apply themselves. We lay our outdoor clothing on bushes and spray it before we get dressed to go outside. We use DEET in the evening when West Nile carrying mosquitoes are a problem.

      • Karen Zeller // July 31, 2013 at 3:16 pm // Reply

        Do you have concerns about permethrin killing beneficial insects?

  8. I’ve had fantastic results from the EcoSMART line, which I discovered a few months. I can’t use DEET (makes me sick) and I had Lyme last year so I’ve done a lot of research since then. EcoSMART’s fogger is great if you’re staying in a localized area of 10-30 square feet (think BBQs, Cub Scout Day Camp, etc.) and the insect repellent was fantastic at CS resident camp two weeks ago. My son and I were the only ones without bug bites or ticks on that trip.

  9. Earl Binder - Greater St. Louis Area Council, New Horizons District ADC // July 31, 2013 at 2:04 pm // Reply

    I spray clothing with repellent that contains Permethrin (pump spray from REI) – It is very effective repelling mosquitoes and ticks. Scout knee socks may not be as “fashionable” as crew or the shorter socks, but I rarely get mosquito bites, chiggers or ticks. Spray T-shirts, socks and underwear OUT OF DOORS on the outside of the clothing, hang to dry, and pack in ziplock bags. It is good through up to 5 washes before you have to re-apply it. Make sure you thoroughly wash your hands & arms after application, and make sure it is a calm day so that the spray doesn’t drift back at you – avoid inhaling it, too..

  10. When I was younger, I used the 100% DEET stuff that you could buy. My body developed an intolerance to it and now anything with DEET on my skin gives me hives. I now use Bullfrog.

  11. James Lehman // July 31, 2013 at 3:20 pm // Reply

    Judging by what was left behind (“lost”) at our CSDC, the DEET products are either (1)very popular (lots of sprays left behind) or (2) very unsatisfactory (lots of sprays left behind). Out of the 12 repellents left behind, 10 have DEET formulations of various percentages. so we have alot of repellent for the family and friends!

  12. I use Permethrin on pants and boots for tick defense. Otherwise, we waver back and forth between Natrapel (Picaridin) and Ultrathon (DEET). I like that Natrapel doesn’t damage gear, but the DEET is more effective and lasts longer. DEET in any decent concentration is bad news for fishing line. I lost a brand new $70 flyline to a DEET mishap..

    • I forgot to mention that apparently fish get one whiff of DEET and they scatter, so I am told

  13. Here’s what I’m really excited about: http://www.kitepatch.com/!

  14. we use deet, but now have rules for the bottle in the house. my son came home from camp with Deet in his pack. somehow the pump on the bottle was damaged and spilled Deet all over the dining room table. in the space of an hour or two, the finish on the table was completely destroyed.

  15. H. David Pendleton // August 1, 2013 at 10:42 am // Reply

    The 2 Scout meetings before Summer camp, our Troop sets up a Permethrin spraying station for the Scouts to use on their shirts, pants, & socks. I only attended the 1st 4 days of camp & never saw a single tick. Only had a couple of mosquitos bother me (in SW Missouri), but I stopped using daily insect repellant on my skin after the first day. My son came home after his 10 days & said the bugs never bothered him the whole time he was at camp.

    • Karen Zeller // August 1, 2013 at 10:51 am // Reply

      But do troops with Permethrin leave their camps without the normal population of beneficial insects — pollinators, etc.? I’ve been thinking about Permethrin for awhile, but hesitated because of this. The fact that it kills all insects that come in contact with our gear makes me wonder if it is consistent with our Leave No Trace ethic.

  16. Gary Wilson // August 1, 2013 at 2:43 pm // Reply

    A couple more flying insect prevention techniques to consider for your repertoire, mostly for non-Scouting situations:

    An Electric Fan. Female mosquitoes find you by following the plume of CO2 emit and then zoom in on your infrared signature. So a simple electric fan on your deck creates a breeze that breaks up those clues. It also makes it difficult for the mosquitoes to fly, and works against other biting insects like green-head flies that are immune to the DEET fumes on the final approach.

    A Fine Cigar. While not currently politically correct, my fellow adult leaders often shared cigars and stories around the campfire after the Scouts all went to sleep. Coupled with the woodsmoke, the mosquitoes left us alone. One cigar a month wasn’t a big health risk, especially when we mostly held them.

    Certainly something not to be done when Scouts are present, but it still helps keep the mosquitoes away on my deck!

  17. I’m heading out on the 1,100-mile Ice Age Trail across Wisconsin on Saturday. I bought an inexpensive bug mesh jacket (with hood) and pants made by Coghlan’s. I also sewed my own set of bug mesh mittens from old tent screen fabric – so I’m completely covered and mosquitos can’t get to my skin. So, I don’t need to use any repellant. I also treated my BSA zip-offs and shirt with permethrin, as an extra layer of defens. You can check how it works at http://hikingdude.com

  18. I’m heading out on the 1,100-mile Ice Age Trail across Wisconsin on Saturday. I bought an inexpensive bug mesh jacket (with hood) and pants made by Coghlan’s. I also sewed my own set of bug mesh mittens from old tent screen fabric – so I’m completely covered and mosquitos can’t get to my skin. So, I don’t need to use any repellant. I also treated my BSA zip-offs and shirt with permethrin, as an extra layer of defens. You can check how it works at http://hikingdude.com

  19. Since I am allergic to Mosquitoes and will blister with almost every bite. I have tried many different type of protection nothing seemed to work well each and every time I went camping until I started using DoTerra Essential Oils. I not sure why you say Essential Oils are not good. I would agree if you had cheep non-pure oils but DoTerra oils are certified pure and they have worked for the past 2 years for me. I have used their TerraShield oil and it works great. This last week long camp I only got 2 bites where most of the time I would get 20 or 30 and have to go on steroids every time I went to camp (for the last 30 years) I have also used Lavender or Lemongrass after any bites and it takes the itch away and starts the healing process within seconds.
    DEET has always caused concerns with regards to it’s safety by consumers and scientists. In 2009 a study found that DEET can interfere with enzyme activity that is vital to our nervous system. The enzyme cholinesterase which is vital to conducting messages from the brain to the muscles of insects is blocked by DEET. Researchers have found that DEET may do the very same thing in mammals. I never liked using DEET for any long periods of time and having been in the Military for over 20 years and now retired this past Jan at age 60 I have been using lots of different stuff. Nothing as worked as good as the TerraShield from DoTerra.!!

  20. Josh Fletcher // August 5, 2013 at 4:13 pm // Reply

    I have used Permethrin for at least the last 5 years for Resident camp and Summer camp. At our camp in Arkansas we like to say the ticks are provided free of charge. I have not seen a tick since using it. We have plenty of other bugs present so I do not think it has a negative affect on them. I would never ever go without it. I read an article in Outdoor magazine about these tick researchers who every day went out in Vermont to study ticks. They were bitten multiple times and had even contracted lyme disease. They never mentioned Permethrin in the article, only in a side bar. I consider them to be idiots for not using the stuff. Like a soldier without body armor.

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