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Choosing the Right DEET Concentration for Effective Protection

What’s the Difference between 100% DEET and 30% DEET

DEET is still the most widely used insect repellent in use today. It is available in multiple concentrations ranging from 10 percent up to 100 percent. The main difference between the different concentrations is how long they remain effective. For example, a concentration of 30% will repel mosquitos and ticks for about 6-8 hours, while a concentration of 100% will last 8-10 hours.

The smell of DEET is highly offensive to mosquitos who avoid the scent. Maximum protection is achieved at 30% DEET formulations, so there is no need to use a higher concentration like 100% DEET if you’re willing to apply it slightly more frequently.

ProductActive IngredientConcentrationHours Mosquito Protection
Ben's 100 Max Formula Insect RepellentDEET95%10
Ben's Insect Repellent Wipes DEET30%8
Ben's Eco Spray Insect RepellentDEET30%6
OFF! Deep Woods Insect Repellent VIIDEET25%8
Repel Sportmens Max Insect RepellentDEET40%10
Repel Sportsmen Insect Repellent WipesDEET30%10
Repel 100 Insect RepellentDEET98.11%10
Sawyer Products Premium MAXI DEETDEET98.11%10
Sawyer Jungle Juice 100 Insect RepellentDEET98.11%10
Ultrathon Insect Repellent Lotion DEET34.34%12

DEET can damage plastic and synthetic gear items, so wash hands thoroughly after use and be careful about it coming into contact with your gear particularly watches, sunglasses, and smartphones. DEET will also dissolve waterproof/breathable fabrics it comes into contact with so careful using it with rain gear.

Some DEET formulations are also available in a slow-release formula, such as Ultrathon, which has a 34.34% concentration of DEET. It is designed to maintain its effectiveness for up to 12 hours, significantly more than products that have a 100% DEET concentration. Controlled-release DEET an excellent option for people seeking to minimize DEET concentration levels on themselves or their children. As a bonus, controlled-release DEET also minimizes the DEET’s effect on plastics and synthetics.

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  1. I’ll never forget on my final morning of my AT thru-hike walking through the woods of Maine slapping mosquitoes off my arms. Stopped counting kills at 70 before I finally put my pack down and got out my little bottle of Repel Deet 100. I sprayed copious amounts on my arms and watched the little buggers hover above my arm for about 30 seconds before they decided that DEET be damned and started landing and biting again like I never even sprayed it. It was worse when they landed on my shirt sleeves because I couldn’t even feel them to swipe them off until they struck.

    Also got to see the destructive side of DEET on a canoe trip where a canister of OFF was inside a dry bag and didn’t realize the trigger got pressed and it was spraying for a long time. By the time we got to camp, the inside lining of the dry bag was turning into liquid.

  2. One time, my wife was spraying her arms with some repellent containing DEET and the overspray bubbled the color layer of the plastic panel on the interior side of the car door. I hate that stuff!

    I do not like the feel of DEET on my skin and use 20% picaridin as much as possible. I also have almost all my clothing, not just my hiking gear, treated with permethrin. As the old saying goes, “There’s no free lunch” and I try not to provide one for the bugs.

  3. The only problem with 25 percent DEET is when you encounter black flies. For me, the only useful deterrent to black flies is 100 percent DEET. I have seen many testimonials to other repellents, but no one ever mentions whether they work with black flies. Do you have any experience here?

    I will note that in the continental US, these pests are usually gone by mid-June; but before that, they can make the woods unusable.

    • picardin. far superior to deet. wont melt your stuff either.

    • The only thing that works for black flies is ole time woodsman fly dope

      Old Time Woodsman

      repels anything including people!

      • Ha! I love the smell of the pine tars and other stuff in Old Woodsman’s. It reminds me of my youth outdoors. It was the only dope I used. That said, I still use it… mixed 50/50 with 100% deet. The Old Woodsmans is for me, the deet is what keeps the bugs away.

        Yes, the Woodsman’s does repel a few people, like my wife, but those of us who love woodsmoke in our clothes and the scent of fresh cut trees, buck in the runt and whiskey; we love Wooodsman’s.

        Nobody mentioned deet as a tick repellent. I find when I spray my pant legs and boots I don’t pick up ticks.

  4. Carry 100% DEET and dilute it in your palm before you lather up.
    Makes it easy to carry concentrate.


  5. Can’t believe anyone hasn’t answered this question yet.

    70% Deet.

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