I'm looking for definitive answers to some of my Permethrin questions.
I used the sawyer permethrin spray last year…and it was a pain to keep squeezing the bottle, flipping clothes over, etc. And, I couldn't do as many clothes otherwise I would quickly run out of spray.
This year I bought Permethrin SFR, a 36.8% permethrin solution. Mainly because I had a mountain of clothes…..for my family of 5. Since I was making such a economical solution of permethrin, I thought…why not do everything. Socks, pants, shirts, buffs, hats, etc.

I made a 3 gallon solution, by adding 6 fl.oz of chemical. Easy enough. That gave me .5% permethrin, just like sawyers.
I then dipped several items of clothing, swished them around for a few seconds, then wrung them out and placed them on a drying rack.
Everything moved fairly quickly…got all of these clothes done in 30 minutes.

I still had over a gallon of solution left, so I bought a 2 gallon hand tank sprayer and then proceeded to spray the outside of my house along the perimeter for insect control. Not that I've paid for insect control before…but I would certainly never pay for it now since it was ridiculously easy to spray your own permethrin.
I then waited for the clothes to dry (took a day since they were only wrung out by hand), and then put the clothes through my washer, then let dry again.
Now….the questions that I hope the community and answer once and for all.
1. The sawyer spray does not give instructions for soaking clothes before hanging them to dry (b/c its a spray). But I've read other instructionals that state you should let the clothes soak in the gallon solution for an hour before you wring them out. Necessary?
2. This 36.8% solution contains petroleum distillates. It definitely smelled while doing the process…basically like DEET or…chemicals. I don't remember exactly but I'm pretty sure the sawyers had no smell, though I used WAY less sawyer spray so I don't know. The clothes did not smell once dry…however, after I took them out of the wash, the smell was back when wet, then after drying it didn't smell again. I went camping and used a set of clothes, and washed again and there was still a faint smell after the second washing when pulling the clothes out of the wash.
The permethrin SFR has 36.8% Permethrin, and states it has petroleum distillates. Here is the MSDS ->
Permethrin 39.1%
Hydrocarbon Solvent 26.0%
Triacetin 25.9%
Surfactant Blend < 10%
Sawyer's spray is:
Permethrin .5%
Aromatic Petroleum Distillate <1%
Inert 98%
Now, that tells me that both products have petroleum distillates….so I'm not sure why the SFR smells so much more…other than I created a lot more of it and the clothes were literally soaked in the solution. Perhaps there is another reason?
There is a permethrin concentrate called Martin's 10%, which I believe is water based so it does not smell at all, and its safe to use on plants, gardens, etc. I've read the SFR is not intended for plants b/c of the petroleum solvent, which is bad for the soil. However, I've also read that the petroleum distillate helps the permethrin adhere to the clothing…so its a good thing. However, most info I read seems like its a bad thing to have the concentrate that has the distillates?
What is the definitive answer between water based, petroleum based, and sawyers spray?
3. I've also read that the sawyer's spray permethrin was specifically designed to adhere better to clothing…with micro encapsulation. The SFR isn't, but anybody have any real idea on how more effective the sawyer spray would be vs SFR? I'm ok with SFR being 5% less effective, but if it adheres 60% worse, I would switch….
EDIT with other questions:
4. Another idea I had for next time…is just to use the tank sprayer to get the clothes wet with solution. I wouldn't haven't to ring out the clothes, saving time there, though I would have to spend a bit more time flipping over clothes, spraying, etc. It would lose less solution, so might smell less….though I would have to be certain every part of the clothes were sprayed…..
5. The sawyer spray says you can do gear. In the pics above, I'm actually doing this all on a polycryo ground sheet I use. So…now the polycryo has been sprayed.
However….is this going to do anything? I would assume if you are going to spray gear, it has to be gear that will absorb water. Like…tent flys that have a "wet" look after spraying. I would assume doing a cuben tarp would make no difference b/c nothing is absorbed, correct?
Kind of the same issue with shoes. I actually used the tank sprayer to spray 5 sets of shoes. The mesh trail runners seemed to work fine, but I had some leather waterproof boots that didn't absorb water when sprayed due to a leather water repellant treatment, so I assume that spraying was completely ineffective?






