Treating your Clothes with Permethrin

Permethrin is a pesticide that you spray on clothing to kill black flies, ticks, and mosquitoes but has no harmful side effects on humans if used properly. It is the active ingredient used in Insect Shield and Buzz Off clothing and kills bugs when they land on your clothing. You can buy Permethrin Spray in liquid form and spray it on your own clothes to the same effect. This self-applied form lasts for 4-6 washings. Permethrin was developed by the U.S. military to protect soldiers from insects in the jungle.

You can buy Permethrin Spray on Amazon. A big bottle comes with a spray adapter and will cover 4 complete sets of clothing, including shirts, pants, and socks. You’ll want to read the directions carefully before applying it, but it’s not difficult to do. You need to spray it on the clothes you plan to wear hiking or for any outdoor activity in a windless but well-ventilated place like a garage. Let them dry for a few hours and you’re all set.

I’ve been spraying Permethrin on the clothes that I wear for spring and summer hiking in New Hampshire and Vermont for over 10 years. This has included long sleeve shirts, convertible hiking pants, gaiters, and hiking socks. When you spray the Permethrin on, you want to position the sprayer 6 to 8 inches away from the clothing you plan to treat. Pay particular attention to the cuffs of long pants and shirt sleeves where ticks will try to attack you. It’s also a good idea to spray it on your hat or to buy one that’s already been treated with Permethrin like the Outdoor Research Bugout Brim Hat. 

Permethrin is EPA approved for use as an insect repellent when applied to clothing and other textiles.
Permethrin is EPA approved for use as an insect repellent when applied to clothing and other textiles.

Sawyer’s Permethrin Spray (24 oz) is pre-mixed to the correct concentration so you can apply it to clothing without any preparation.

I can attest to the effectiveness of Permethrin Spray particularly against mosquitos and ticks. I rarely ever get bitten as long as I wear a long-sleeved permethrin-treated shirt and pants when I go hiking in the forest. I love having the sun on my arms and legs as much as the next guy, but I’d rather cover up than catch Lyme disease, which the CDC believes is now 10 times more prevalent than previously reported.

More about Permethrin

As a treatment for clothing, Permethrin clothing insect repellent does not harm fabrics and is odorless after it dries. Use Permethrin on clothing by itself or with skin-applied repellents to create the ultimate protective, armor-like insect barrier. Permethrin-treatments on clothing are non-toxic to humans and are registered for use by the U.S. EPA.

The active ingredient, Permethrin, is a synthetic molecule similar to those found in natural pyrethrum, which is taken from the chrysanthemum flower. Not only does this product repel insects, but will actually kill ticks, mosquitoes, chiggers, mites, and more than 55 other kinds of insects.

Permethrin insect repellents are for use with clothing, tents, and other gear. During the drying process, it tightly bonds with the fibers of the treated garment. It will not stain or damage clothing, fabrics, plastics, finished surfaces, or any of your outdoor gear.

Permethrin is a contact insecticide, meaning that kills ticks or other insects when it comes in contact with them. It uses the same active ingredient used in hair shampoos for head lice. When applied to clothing the Permethrin binds to the fabric eliminating the risk of over-exposure to the skin. As a clothing, tent, chairs, or sleeping bag application, Permethrin is very effective at keeping ticks from attaching to you and at reducing the mosquito population in your camping area. While ticks usually find you at the ankle level (be sure to treat the socks and pants) they can also climb bushes and find you at a higher level so be sure to treat your shirt as well if you are around bushes and concerned about ticks.

Sweating and exposure to water do not significantly deteriorate the application. It is primarily the agitation of a washing machine, which deteriorates the Permethrin application as it knocks the molecules loose from the fabric. For best results, Sawyer recommends hand washing and air-drying. When using a conventional washer and drier, use the gentle wash and dry cycles. Loss due to the drier is limited compared to the detergent and washer agitation. Dry cleaning removes the Permethrin from the fabric.

Permethrin Spray can last up to six weeks through six weekly washings. All treatments are non-staining and not greasy. Always follow the directions for use on the package label. Factory pre-treated Permethrin clothing, however, lasts for 70 washings and is far more convenient if you don’t want to spray your own clothing.

See Also:

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  1. Do you treat garments that have a DWR? For example, would you treat your rain jacket? I am wondering if that could damage the DWR, or alternatively if the DWR would prevent the permethrin from being absorbed. I know you can treat gear made out of silnylon, but I would like to check before applying it to some Gore-Tex type garments!

    Also, wouldn’t soaking the garments in the solution be more efficient than spraying it on? The longer the fibre is soaked, the more permethrin should be absorbed I assume. I have used Sawyer spray before, and I did notice that it worked better on my merino wool layer than my polyester ones. The permethrin on the polyester layers seemed to wear out faster as well, which I guess has to do with the fact that polyester does not absorb water to any significant extent, and the solution is water-based.

    • I don’t treat rain gear. Just shorts, pants, socks, hats. The items that are the first and last line of defense again insects. It’s not recommended that you do underwear. Yes, soaking is more effective, but it all washes out in 6 washes anyway. When I spray, I soak the garments full of permethrin. But if you want a longer-lasting treatment, it’s best just to send stuff away to Insect Shield. I have a coupon on my home page if you want a discoumnt

  2. Personally I don’t feel the need to treat every piece of clothing (i.e. rain gear). With rain gear you’re going to be wearing clothing under it so THAT is the clothing I want treated. A tick is going to need to be on that clothing before he gets to your skin so I feel that’s the protection layer.

    In any case, yes – you are correct – that the effectiveness and longevity of the permethrin is going to be partially determined by the ability of the piece of clothing to absorb it.

  3. Do you have to fully saturate the material? Some people in my family are uncomfortable with the idea of the chemical contacting the skin and would prefer to just spray the outside of our socks, boots, and bottom pant legs.

    • I have this same concern and would appreciate a response that addresses what happens when you sweat in clothes that touch your skin. Also, the Permethrin bottle says not to treat hats. I was planning to treat the outside part of a ball cap. It looks like you treat hats. How do you do that? Thanks much.

      • Nothing happens. The permethrin bonds to the fabric at a molecular level. It doesn’t sweat off when you perspire.
        My hats are factory all pre-treated with Insect Shield by the manufacturer. But I wouldn’t hesitate to treat a hat if they weren’t.

  4. Is this dangerous to kids can you spray on kids clothes..

    • Yes, it’s perfectly save to put on kids clothes. Most people don’t put it on underwear though.

    • I have hunting clothes for hot weathwr and they provide excellent airflow. Would this product block or restrict the airflow of the clothing?

      • It doesn’t affect it at all. It’s like polygiene or the other chemical treatments that hunting gear manufacturers put on cloth. It bonds to the fabric at a molecular level that’s too small to interfere with breathability.

  5. Previous permethrin labeling says to use on hats. Recent labeling says not to use on hats. I have hiked through wooded areas with low lying branches without permethrin hats and have pulled ticks off my face and neck. Since then I have sprayed my hat with permethrin, let it dry well, and worn the hat with no eye, mouth, or breathing problems. And no ticks! Why the recent stern warning about not using permethrin on hats ? If the sprayed hat is allowed to dry well do you see a risk to wearing the hat. Thanks. JP

    • I wear an insect shielded hat every day (which is just longer lasting permethrin). No ticks on me! Can’t imagine why they stopped recommending it or if they did. I haven’t seen any change in labeling. Companies are still selling Insect Shield hats, so draw your own conclusion from that.

    • I am only conjecturing, but permethrin is a neurotoxin for insects. Though it has shown to have very low, to nil effects in humans, having it on your head next to your brain on a continual basis might be less than cautious.

  6. Should we also spray arm sleeves, or do the sleeves themselves keep insects off?

  7. Do I need to wash the treated clothing before initial donning?

  8. Once dry, do treated cloths pose any risk to fish or other aquatic life? For example wading a lake or stream with treated pants?

      • Per the Florida Department of Agriculture permethrin in liquid form is toxic to fish and aquatic invertebrates. So do not spray it anywhere near your tropical fish or pour it down the drain. However once dry the amount you on your clothing will affect a stream or pond so it is OK to use on fishing trips.

  9. Is it safe to spray permethrine on bed sheets? We will be in Kenya and will be provided mattresses but no bedding. As Kenya has endemic malaria the protection is important. Once permethrine bonds with the fabric can you still absorb it through your skin?

    • Once it dries it does bond to the fabric, but I wouldn’t advise sleeping naked on your sheet. Insect Shield advises against it coming in contact with the genital areas. Frankly, you’d probably be better off sleeping with a permethrin-treated insect net, which is much more common and taking prophylactic anti-biotics when in-country. Talk to your doctor, local tropical medicine clinic, or public health department for expert advice.

    • As Phillip says, insect net over the bed for mosquitos and prescription anti-malarial medication, depending on exactly where you’re going. Conditions vary widely. I use an ultra-light permethrin-treated sleeping bag liner form Sea-to-Summit against bed bugs, fleas, spiders, etc. You might want to wear underwear to keep it away from your groin.

  10. I loved it when you said that as a treatment for clothing, Permethrin clothing insect repellent does not harm fabrics and is odorless after it dries. My wife is complaining about bugs every time we were on our patio. I will surprise her with an insect repellent shirt on her birthday to get rid of the bugs every time we stayed on our patio.

  11. If it’s a cold day, do you wear the treated clothing over your base layers or sweaters, or do you wear the treat clothing next to your skin?

  12. Pump vs aerosol spraying on clothing?

  13. Hi,
    Spraying Permethrin for my clothes (heading to Kenya). I couldn’t help but get some on my skin.
    Should I worry? I washed it off well with soap and water after spraying all clothes.
    Also wondering where I should dry clothes off? Currently in bathroom with windows open and fan on.

  14. Would you need to wear permethrin-soaked long sleeve shirts? I am wondering if you could just spray your arms with picaridin and use short sleeves. Do ticks attach above 3 feet anyways?

  15. Thanks, Phil. I’m a bit late in replying to your comment. I was curious because some people say that ticks can drop out of trees onto you. However a tick researcher from the University of Rhode Island told me that ticks don’t do that. It’s more efficient for them to attach to prey that brushes against them. He also said that they’re generally found at knee height or less. So it makes sense that the tick attached to you when you fell. Thanks for all the information you provide.

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