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Permethrin-treated clothing

Prevention Updated Jul 2026 6 min read
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The short answer

Permethrin is an insecticide you put on clothing and gear, not on your skin. Once it dries on the fabric, it kills or repels mosquitoes and ticks that land on you, and it keeps working through repeated washing. You can buy clothing that comes pre-treated from the factory, or you can treat your own clothes with a spray-on product. Either way, the rule is the same: it goes on fabric, never on bare skin (NPIC, Permethrin Treated Clothing; CDC, About Permethrin-Treated Clothing and Gear).

Think of it as protection built into what you wear, which pairs well with a skin repellent on the parts of you that clothing does not cover.

How it works

Permethrin is an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like the natural insect-killing extracts found in chrysanthemum flowers (NPIC, Permethrin General Fact Sheet). It works on contact. When an insect touches the treated fabric, the chemical attacks its nervous system, causing muscle spasms, paralysis, and death (NPIC, Permethrin General Fact Sheet). Ticks that crawl across treated cloth become uncoordinated and fall off before they can bite.

The reason it lasts is that permethrin bonds to the fibers of the fabric. When applied properly, it binds tightly and comes off only slowly during washing, with very little transferring to your skin (NPIC, Permethrin Treated Clothing). That tight bond is what lets a single treatment survive multiple laundry cycles instead of rinsing away the first time the garment gets wet.

Treating clothing yourself vs factory-treated gear

You have two ways to get permethrin onto your clothes, and they differ mainly in how long they last.

Spray-on, do-it-yourself. You buy a permethrin spray and apply it to your own clothing, boots, and gear. A common product, Sawyer’s fabric treatment, states that one application “bonds to fabric fibers for up to 6 weeks or through 6 washings,” whichever comes first, after which you re-treat (Sawyer Products). Most of the loss happens early: after the first wash roughly 20 to 30 percent of the treatment is removed, then only about 3 to 5 percent per cycle over the next several washes (Sawyer Products). Spray-on treatment is inexpensive and lets you treat items you already own.

Factory-treated. Some clothing is treated during manufacturing, or you can send garments to a service that treats them for you. Factory treatment lasts far longer. Insect Shield, one such service, states its treatment lasts through 70 washings and is expected to last the effective lifetime of the garment (Insect Shield). This costs more per item but does not need reapplying.

The general pattern holds across sources: self-applied spray lasts a handful of washes, while factory treatment lasts dozens. In both cases the product label is the authoritative guide to how long protection lasts, because it varies by product (CDC, About Permethrin-Treated Clothing and Gear).

Safety

Used the way it is meant to be used, on fabric, permethrin-treated clothing is considered low-risk for the person wearing it. The amount allowed in clothing is very low, and studies show human exposure from wearing factory-treated clothing is also low, because permethrin is poorly absorbed through the skin (EPA, Repellent-Treated Clothing; NPIC, Permethrin Treated Clothing).

A few clear cautions:

  • Never apply it to skin. Permethrin treatments are only intended for fabric. Do not put them directly on skin, and do not apply spray to clothing while you are wearing it (NPIC, Permethrin Treated Clothing; CDC, About Permethrin-Treated Clothing and Gear).
  • Be careful around cats while it is wet. Cats cannot break permethrin down the way people and dogs can, so they are unusually sensitive to it (NPIC, Permethrin General Fact Sheet). The risk is highest while the treatment is still wet. A veterinary toxicologist quoted by NPR put the rule simply: keep the cat away until the permethrin on your clothes has dried (NPR, “If You Spray Your Clothes With Permethrin, Be Careful Around The Cat”). Apply and dry treated items where cats cannot reach them, and let everything dry fully before bringing it near a cat.
  • Dry it fully before wearing. Hang treated fabric outdoors and let it dry completely before you put it on (NPIC, Permethrin Treated Clothing).

How to apply

If you are treating your own clothing with a spray-on product, follow the label, and in general:

  1. Work outdoors in a well-ventilated area that is protected from wind (NPIC, Permethrin Treated Clothing).
  2. Lay the garment flat and spray fabric only. Never spray it while it is being worn (NPIC, Permethrin Treated Clothing; CDC, About Permethrin-Treated Clothing and Gear).
  3. Let items air dry completely before wearing. Product directions commonly call for at least two hours of drying, or longer until fully dry (Sawyer Products).
  4. Keep cats away from the wet clothing during application and drying (NPR).
  5. Wash treated clothing separately from your other laundry (NPIC, Permethrin Treated Clothing).

Using it with a skin repellent for full coverage

Permethrin clothing and a skin repellent do different jobs, and using them together gives the most complete protection. The treated clothing guards the skin underneath it. An EPA-registered repellent (such as one with DEET or picaridin) applied to exposed skin covers the gaps that clothing leaves, like your face, neck, and hands. The CDC recommends both approaches as part of preventing mosquito bites (CDC, Preventing Mosquito Bites). Do not rely on permethrin clothing alone if much of your skin is uncovered, and remember permethrin itself belongs only on the cloth.

Sources

  1. National Pesticide Information Center (NPIC), “Permethrin Treated Clothing.” https://npic.orst.edu/pest/mosquito/ptc.html (accessed 20 July 2026). Primary source for how treated clothing works, fabric binding, skin-application warning, and application steps.
  2. National Pesticide Information Center (NPIC), “Permethrin General Fact Sheet.” https://npic.orst.edu/factsheets/PermGen.html (accessed 20 July 2026). Source for pyrethroid classification, mode of action on insects, and cats’ sensitivity to permethrin.
  3. Centers for Disease Control and Prevention (CDC), “About Permethrin-Treated Clothing and Gear.” https://www.cdc.gov/mosquitoes/prevention/about-permethrin-treated-clothing-and-gear.html (accessed 20 July 2026; page returned HTTP 403, claims taken from CDC search-result excerpt). Source for protection persisting through multiple washings, label as the guide to duration, and do-not-use-on-skin guidance.
  4. US Environmental Protection Agency (EPA), “Repellent-Treated Clothing.” https://www.epa.gov/insect-repellents/repellent-treated-clothing (accessed 20 July 2026). Source for permethrin as a pyrethroid insecticide, low wearer exposure, and factory-treatment safety findings.
  5. Sawyer Products, “Permethrin Fabric Treatment.” https://www.sawyer.com/product/permethrin-fabric-treatment-insect-repellent-24-oz-trigger-spray (accessed 20 July 2026). Source for spray-on duration (6 weeks or 6 washes), per-wash loss figures, and drying time.
  6. Insect Shield, “How to Wash Permethrin Treated Clothing.” https://www.insectshield.com/blogs/blog/how-to-wash-permethrin-treated-clothing (accessed 20 July 2026). Manufacturer source for factory-treatment durability (70 washings, lifetime of the garment).
  7. National Public Radio (NPR), “If You Spray Your Clothes With Permethrin, Be Careful Around The Cat” (2018). https://www.npr.org/sections/health-shots/2018/07/11/627843581/if-you-spray-your-clothes-with-permethrin-be-careful-around-the-cat (accessed 20 July 2026; page timed out on fetch, quote taken from NPR search-result excerpt). Source for the veterinary guidance to keep cats away until treated clothing has dried.
  8. Centers for Disease Control and Prevention (CDC), “Preventing Mosquito Bites.” https://www.cdc.gov/mosquitoes/prevention/index.html (accessed 20 July 2026). Source for combining treated clothing with an EPA-registered skin repellent.

Related

Educational note: This page is general reference information, not medical, veterinary, or pest-control advice. Always follow the specific product label, and consult a professional for questions about your own situation, including exposure concerns for children, pregnancy, or pets.

Last reviewed 20 July 2026.