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Permethrin Soak Method Guide

You can buy a pre-mixed Permethrin soluton like Sawyer Permethrin or dilute a highly concentrated form with water if you need to treat bulky gear or many clothes in order to save money
You can buy a pre-mixed Permethrin solution like Sawyer Permethrin (left) or dilute a highly concentrated form like 10% Martins Permethrin (right) to save money if you need to treat bulky gear or numerous clothing items.

Permethrin is an insect repellant and insecticide that bonds to fabric and can be used on your clothes, tent, or hammock to prevent Lyme Disease, Rocky Mountain Spotted fever, or the Zika Virus by killing ticks, mosquitos, and insects that land on your stuff. The liquid Permethrin application techniques discussed below are only for treating clothing or outdoor gear and are not intended for human or animal use.

Soak or Spray: Two Ways to Apply Permethrin to Clothing and Gear

There are two ways to self-apply Permethrin to clothing, tents, and hammocks: spraying or soaking. Spraying your clothes or gear is a convenient way to treat them with Permethrin if you have a limited number of items. To learn more about the spray method using pre-mixed Sawyer Permethrin, see Treating Your Clothes with Permethrin. Soaking your clothes in Permethrin is the second way to treat clothing or outdoor gear and can be useful when you have bulky or a large number of items to treat. I explain how to do this below.

Permethrin treated clothing kills the ticks that land on it as long as you retreat your clothing periodically to maintain its effectiveness
Permethrin treated clothing kills the ticks that land on it as long as you retreat your clothing periodically to maintain its effectiveness.

How long does Permethrin Treated Gear and Clothing Remain Effective?

Both methods of Permethrin self-application, spraying and soaking, remain effective for 6 weeks or 6 washes. You can prolong the effectiveness of self-applied Permethrin by storing permethrin treated gear or clothes in black plastic bags (since sunlight breaks down Permethrin) or by hand washing items because the agitators in washing machines also accelerate its decay.

There’s anecdotal evidence that soaking your clothes with Permethrin instead of spraying is effective longer, but there isn’t any publicly available laboratory to support that conjecture. It’s just common sense that soaking will penetrate both the inside and outside of a garment, while spraying it will just cover the outside.

If you want a longer lasting treatment that will last up to 70 washings, you can send your clothing to a company called Insect Shield which has developed a proprietary process for Permethrin application that lasts longer than what you can do a home. I have no idea what they do that’s different, which is probably why they keep it a trade secret. Here’s a link to the Insect Shield order form that you use to send clothing you want them to process. The prices are listed on the form.

You can also buy Permethrin treated clothing off-the-shelf from many manufacturers.

Why would you soak clothes with Permethrin instead of spraying them?

Soaking can be more convenient if you have bulky items (tent or hammock) you want to treat or many articles of clothing. Soaking is also likely to provides better coverage than spraying, including the inside and outside of garments than spraying which may miss spots. If an insect avoids the outside of a garment and makes it to your skin, there’s a good chance that it will still be killed if the inside of your clothing has also been pre-treated with Permethrin.

Martin's Permethrin 10%
Martin’s Permethrin 10%

What is the most economical way of soaking gear and clothes with Permethrin?

While you can soak items in the pre-mixed 0.5% Permethrin Solution sold by Sawyer, it is more economical to buy a highly concentrated Permethrin solution like Martins 10% Permethrin and dilute it down to the recommended 0.5% strength solution recommended for treating fabrics.

While often intended for veterinary or agricultural use, highly concentrated Permethrin solutions diluted to a 0.5% Permethrin concentration are thought to be as effective at killing insects as the pre-mixed 0.5% Sawyer Permethrin solution. No one knows definitively in the absence of laboratory testing, although anecdotal accounts from many people suggest this to be the case. Follow all manufacturer product instructions and use at your own risk.

How to dilute concentrated permethrin.

If you choose to dilute a concentrated form of permethrin like Martin’s 10% Permethrin, you need to reduce it to the 0.5% concentration recommended for clothing treatment. A 32 ounce (1 quart) size bottle of Martin’s 10% Permethrin comes with a built-in measuring cup which is useful for this process.

I prefer bagging up the clothing I plan to treat with Permethrin in 1 gallon freezer bags before pouring the Permethrin solution over them and letting them sit and soak.
I prefer bagging up the clothing I plan to treat with Permethrin in 1 gallon freezer bags before pouring the Permethrin solution over them and letting them sit and soak.

If you use a 10% Permethrin concentrate, you want to dilute it with 19 parts water and 1 part of 10% permethrin concentrate to produce a 0.5% Permethrin solution. For example, if you wanted to make a gallon (128 ounces) of a 0.5% Permethrin solution using water and a 10% Permethrin solution, you’d mix 6.4 ounces of 10% Permethrin solution with 121.6 ounces of water. If you do this using a 1 gallon plastic water bottle (shown above), you’d pour off 6.4 ounces of water and replace it with 6.4 ounces of the 10% Permethrin concentrate. Shake well to mix it up.

Precautions. Martin’s 10% Permethrin is a neurotoxin and you do not want to get it on you or inhale its fumes. See the manufacturer’s safety sheet for more information. I recommend wearing protective gloves when working with it, keeping it away from all animals, food, and water supplies, and only using it in a shady, well-ventilated, outdoor area. All of the containers used to hold Permethrin should also be properly labelled and disposed of as recommended on the product label by the manufacturer.

Pour enough Permethrin solution to soak each item and then let sit for a few hours so that ot fully soaks the material.
Pour enough Permethrin solution to soak each item and then let sit for a few hours so that it fully soaks the material. Sawyer recommends 3 ounces of 0.5% Permethrin solution per garment.

What’s the best way to soak your clothes with Permethrin?

While you can dip your clothes in a large bucket of 0.5% Permethrin, I prefer bagging them individually in 1 gallon freezer bags and pouring a smaller quantity of Permethrin solution into each bag. This eliminates having a large amount of left-over Permethrin that is complicated to safely dispose or store.

I then massage the liquid into the garment and let it sit for a few hours to fully soak through all the layers of clothing, before pulling it out of the bag and hanging it up to dry in the shade. Sunlight breaks down Permethrin, so you should avoid drying Permethrin soaked clothing on a clothesline in the sun.

Once dry, the Permethrin treated clothing is ready to wear
Once dry, the Permethrin treated clothing is ready to wear.

Once the garments have dried, they’re ready to wear. There’s no need to wash them or dry them in a drier before use. Doing so will only begin to break down the Permethrin that has bonded to the garment’s fabric.

Can you soak clothing using pre-mixed 0.5% Sawyer Permethrin?

Absolutely. It can be far more convenient to soak your clothes using Sawyer Permethrin since it’s pre-mixed to the correct 0.5% concentration without having to dilute concentrated Permethrin, safely dispose of contaminated containers, or left-over Permethrin solution. It’s just more expensive.

Liability Disclaimer: The author of this article and website is not responsible any damage, personal injuries or death as a result of the use of any information, maps, routes, advice, gear or techniques discussed herein. All activities are carried out at your own risk.


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53 comments

  1. Hi Section Hiker, I could only find 0.25% Permethrin (Wilson’s) solution at a large hardware chain. I’ve sprayed my gaiters and a couple pairs of shorts. Will this concentration be effective enough? even just as a deterrent to ticks? Thanks!

    • It’s probably just less effective. The bugs are killed when the come on contact with a permethrin molecule. Fewer molecules means less efficacy. It’s your risk…

      • Hi SectionHiker, I sprayed my Tilly’s with 0.25% Permethrin and took them for a test hike in a pretty buggy area, like around some beaver ponds. The bugs, even the horseflies, don’t like it one bit. They’ll buzz around, quickly land but bugger off just as quickly. I had not one bite.

    • Look for Hi-Yield 38-Plus. It’s has 38% permethrin. Amazon sells a 32 oz bottle for $30. That one bottle will make 19 gallons of 0.5% mix. Compared to Sawyers, which would cost you $53 per gallon, buying it this way and making it yourself will cost you $1.55 per gallon.

      Here’s the link: http://amzn.to/2dS1rhY

      If you go this route, add 3.4 tablespoons of the permethrin product to a gallon of water.

  2. I’ve been doing this for some time. You can often buy the concentrate at feed stores. There’s a local one that deals with all things horse and they carry it. It’s also available on eBay… can’t say fleaBay, because those critters would be dead!

    I put some of my poured off solution in a spray bottle and spray the perimeter of my tent when car camping in tick country.

    • Feed stores? You can walk into any REI and buy this stuff! Most hardware stores and garden centers also carry it. Or AMazon, which is where I order mine from.

    • Thank you for mentioning feed stores. Not all of us live near an REI, but some of us live near a feed store so that is another option.

  3. Does Permethrin affect the waterproofing of a tent or break down the fabric in any way?

    • Dave, I would suggest you get one of the concentrates that has the lowest amount of petroleum distillates. A lot of the mixtures sold at the feed stores and online have a higher concentration of PD which appear to be solvents and thus might damage your seam seals, etc. I found Martin’s makes a Permethrin 10% with no PD listed on the label (which would indicate that the PD percentage is below 10%, IIRC), whereas all the other concentrates I found had the PD warning. For example, there is a 36.8% Permethrin that I was going to buy since that’s the most cost effective, but I opted for the 10% with lower PD since I was not sure how much of a problem the PD might present to the different types of clothing, especially technical clothing, I plan on soaking. Hope that helps!

  4. Very timely post. I am considering treating my clothes with permethrin for the first time. Phillip, is there any information that you know of regarding the potential toxicity of wearing clothing treating with permethrin? I am also curious what you think of picardin versus deet. Sometimes the smell of deet is repulsive and I am looking for an alternative.

    • Permethrin used as directed is perfectly safe for clothing. I’ve been using it for years. I prefer 100% deet but rarely need to wear it because I’m wearing full coverage clothing treated with permethrin.

    • I’m another who hates the smell and feel of DEET. I use picaridin as much as possible. Picaridin doesn’t seem to last as long as DEET and, for me, isn’t as effective in lower concentrations, however, I still use it over DEET.

  5. Once you’ve completed soaking a garment in the Permethrin solution, using a 1-gallon freezer bag, can you reuse the same solution to treat another garment?

  6. Thanks for the info. The spray bottle of Sawyer is about 22 oz so I just keep re-using it by adding one ounce of the 10% concentrate and refiling it a little short of the top. Not exactly 0.5% but the bugs don’t seem to notice. I never mentioned this to anybody because I thought it it was too “fringe”. Now I don’t feel so weird when I am doing it.

  7. Bought concentrate at Tractor Supply. Diluted it to .5-.10% -/+. Used a Harbor Freight garden sprayer, laying each item in a makeshift spray box. The best of both soaking and spraying!

    BTW – what the heck is a “technical hike” and why is it called that? Are other hikes not genuine hikes?

    • Not sure what context you saw the word “technical”, but some hikes are more technical than other if they require climbing gnarly mountains on exposed rock or off-trail. It’s just a figure a speech though. They’re all hikes.

  8. Never leave a trailhead without permethrin treated clothes, shoes and gear!Too many insidious, rare but terrible spirochete diseases out there carried by microscopic ticks you won’t even see. And don’t forget head and tent mosquito nets. Greatly reduces bugs buzzing against them. Makes them keep a respectful distance. The concentrated liquid is on ebay too.

  9. A couple of caveats about usage, as cited in the “permethrin” Wikipedia entry: “Permethrin is extremely toxic to fish and aquatic life in general, so extreme care must be taken when using products containing permethrin near water sources. Permethrin is also highly toxic to cats, and flea and tick-repellent formulas intended and labeled for (the more resistant) dogs may contain permethrin and cause feline permethrin toxicosis in cats.”

  10. I’ve been soaking my hiking clothes in Martin’s permethrin the last couple years. Never see ticks anymore. Have no idea what happened to them, but I’m happy they are gone. I found usually one treatment in the Spring was good for the year. YMMV and all that.

  11. Does this stuff wash off like DWR and get into the environment and food chain?

  12. As mentioned, permethrin is highly toxic to cats, so keep your kitty away from all permethrin treated products as well as from the treatment area. It’s also bad for vital pollinators like bees and butterflies. Do be cautious and follow the label instructions carefully. Unfortunately permethrin does not affect biting flies (that’s on the label, too). It’s the same stuff used in the various “bugs off” brands of clothing.

    Rather than spraying shoes and socks, which will get into the water during stream crossings, wearing lightweight low gaiters, if fastened over your pant legs, will keep ticks from getting inside your pant legs. You can then just spray/soak the pant legs above your knees.

    • WET permethrin is highly toxic to cats. Once dry, it is not. Still, I would hesitate to treat the cat’s bedding with it, even though I have seen absolutely no warnings about this anywhere.

  13. One of the wonderful things about permethrin is its not a persistent toxin. It breaks down in the environment. It’s fairly safe to cats and fish once it’s bonded to clothing. Sunlight breaks it down. One way to dispose of it is to pour it out onto your driveway and let it dry and have the sun render it non-toxic. There are lethal dose levels that will affect bugs. Splashing through a stream will not affect anything downstream. You want to spray your lower pants legs, shoes and socks, too.

  14. As long as you don’t spray your cat with it it’s fine. Same caveat as with flea drops on cats. They lick themselves and swallow it. Don’t use on cats. I have used permethrin as a dog dip and used flea drops containing it on my dogs, and the drops are direct skin contact with never a rash or reaction in my experience. Not recommended for humans! Clothing and gear treatment is enough.

    I’ve read that permethrin used for decades by US military on clothing with no widely reported evidence of any problems.

    Rocky Mtn spotted fever and babesiosis among many, are the risk of not using it. These can be as tough to kick as the widely known Lyme disease. Permethrin a must on children’s clothing and bedding IMO, even in summer camps.
    It’s no joke. See:

    http://www.cdc.gov/ticks/diseases/

  15. Great article. Any idea on the amount of Permethrin to add to a gallon bag to treat, say, an Ex Officio shirt? Also, when you mix yourself is there a shelf life issue? The reason I ask is that the Sawyer stuff smells allot different than the stuff I mix up with water.

  16. Good tips and tricks. No more ineffective au naturale oil sprays…

  17. Permethrin kills cats. Remember this, as cats for some reason are different than humans in this respect. My friends accidentally killed their two cats when the sprayed permethrin on their yard to kill ticks. Just a fact, but important if you have pets you have to be extremely careful with this stuff!

    • But once dry, the research out there indicates it is safe even for cats, so somebody wearing treated clothing should not be concerned about coming in contact with cats. While wet, permethrin is toxic to humans and pretty much everything, so be very careful working with the wet product (gloves, mask, eye protection), and this is not always emphasized enough on some permethrin containing products. Once dry, it is bonded and harmful only to the smallest organisms. Of course we will probably find out in ten years that even in the bonded form it causes some long-term ill effect, like most things. =)

    • It is toxic to cats WHEN WET.

  18. I know it is dependent on the garment, but for the clothing you have pictured hanging up to dry, how much of the solution did you pour into each zip lock bag?

  19. And for the people who want 70 washes before re-treating, I must say that Insect-Shield has GREAT service and turnaround time.
    Thanks, Philip, for the instructions on how to soak tents, clothes, etc in permethrin.
    I suspect that there are other diseases out there carried by ticks. Here’ s a new local one: Heartland Virus Syndrome https://en.wikipedia.org/wiki/Heartland_virus
    And for sanity’s sake, permethrin works well for chiggers. Darn things want to feed where the sun don’t shine!

  20. The Heartland virus reference mentions the standard tick bite prophylaxis dose of doxycycline. I asked for and got this once after a bite. I think it was 100mg twice a day for 5 days. Doxy available from some vet supplies too. But useless of course against a virus!

    I once backpacked with a guy who earlier had what was eventually diagnosed as RMSF – Rocky Mountain Spotted Fever. The doxycycline treatment might have worked but he had no known tick bite. Doctor said could be from an unseen tiny, almost microscopic tick. Here permethrin very likely would have warded off several months of disabling sickness and close to a year for full recovery.

    Thanks to Philip for raising public awareness of the easy way to prevent these really bad tick borne diseases.

  21. Thank you Phillip. This answers most, if not all, of my questions.

  22. Has anyone seen any sediment that look like small elongated clear crystals on the bottom of the Permethrin bottle? I wonder what it is.

  23. Just followed your instructions to the letter and find that the dried clothes have a heavy chemical smell…is this normal??

  24. Are there any problems with storing the diluted solution as long as it’s stored out of the sun?

  25. How do I dispose of the permethryn once the garment has been soaked in it?

    • Let it dry/evaporate in sunlight. That will break it down and you dispose of the container.

    • I put my excess runoff into a well labeled spritzer bottle and take it with me on car camping trips. I spray the outside perimeter of the tent and the entrance area to keep the little critters at bay. I also use it to spray my shoes and boots before I leave on a trip.

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