[pct-l] Permethrin

[Ken Murray]

I was wondering about the 3M Ultrathon repellant does it actually last as long as they say?   Can you give us a procedure on how you process your cloths with permethrin?   

Why not use a 13% concentration, how long to soak, do you rinse after, does the make up of the cloth matter, etc.?
 
Thanks,  Jim
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Jim, I've used Permethrin on my clothes working on trail crews for the last ten years.  YES, it actually works as well as advertised!  I generally treat my clothing at the beginning of summer, once, and that does it for the year.

The key I find, is to get the clothing SOAKING wet, not just misted.  

The standard for this is the product made by Sawyer, which is 0.5%.  I have found and used a cheap product at the 99-only store, which was a lower concentration, but it didn't seem to matter, as long as I soaked the clothing.  The type of cloth does not seem to matter.  You do not need to rinse after.  I apply by putting my shirt on a hanger, then using the spray to saturate those areas I want covered, leave until dry.  I've also used a plastic bag, and dumped a couple spray bottles worth in with my shirt, mixed well, and hung to dry.

I have not seen Permethrin available in concentrations higher than 1%, like Jerry mentions,  except for other uses.  I'd be cautious about higher concentrations.  The general rule is that almost anything can be irritating if in a high enough concentration. I'd use what works and is recommended, and not go higher.

Here is the MSDA sheet for Sawyer Permethrin:  http://www.sawyer.com/msds/MSDS%20SP649%2012oz%20S-PTR-02.pdf

Occasionally, people ask about safety.  Permethrin 1% is the treatment for lice in children.  We coat their entire body with the stuff, and leave it for 8 hours. Reactions are virtually unheard of.