Definitive answers to MYOG Permethrin

[DGoggins]

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?

[Adam Kilpatrick]

Interesting.

I've done soak based permethrin and also used the sawyer spray bottles. Hard to know which is actually more effective without scientific testing, however;

a) the total amount of permethrin in the sawyer spray product is very low. You just surface spray it.
b) the soak products have a higher proportion of permethrin, and, for a fabric that is not WPB or DWR (I wouldn't do it to those…chances are it will screw them up or be a waste of time as it won't adsorb/absorb) chances are it is soaking in and adsorbing/absorbing to a much higher surface area than is possible than with the sawyer product, thus, in total, more permethrin in your fabric.

The sawyer product may still be effective…again without testing, what is the minimum effective dosage required of permethrin on a fabric? It might be just as effective as the soak products, however I suspect that after a couple of washes or a few days of wear and sweating, the soak products are still working and effective whereas the sawyer product's effectiveness will start to diminish.

Personally, I don't think I'll use the Sawyer product again unless there was a specific reason. As you have done, there's nothing stopping you from putting the soak product in a sprayer/spray bottle to apply to difficult things like the mesh parts of a tent (you don't want to soak the whole tent). Where I might use it (and what I did last time) was part way into a big trip. We were a month into a 9 month cycling trip and about to head to Africa after a month in Australia. We didn't use our treated permethrin clothing, etc, much, and we had a big drop box for a few days before we flew to Africa. In that we had the Sawyer spray product, so we topped up the treatment on things we had used and then used what was left on the mesh parts of our Tarptent moments.

Putting it on polycryo…I suspect that it dries and adsorbs to it. For how long…hmmm. Could well come off in the first wash/wet usage in the field. Its definitely not soaking in for long term durable effectiveness.

I suspect that the water based permethrin products are MORE water soluble, and thus, not as long term durable as the petroleum based products. Simple chemistry. Someone with better chemistry (or at least can remember chem 1 and 2 from uni, I can't remember much) can chime in though on this!

[John Vance]

I used the same product you have used and the same methods, except I doubled the solution. It was very effective, however, I did develop a rash on my wrists and ankles where skin was in direct contact with the treated clothing that lasted the entire trip of 12 days. The smell was much stronger than Sawyers I think due to the solvents but it wasn't bad. I too have been using it around the house and yard with great success but decided not to use it again on my clothes due to the rash issue.

I went back to treating with Sawyers before every trip as it doesn't seem to last very long. In all fairness I have been using this more for Mosquitos than ticks and as an insecticide it isn't the best repellant. I do feel better knowing that I may have been bit but the critter most likely died in the process. Combining this with a true repellant and head net has worked wonders. I still treat the mesh on my shelter with the aggressive solution and must admit I enjoy watching the little buggers land and crawl around a bit before dropping off and dying.

I would just check for any allergic reactions and perhaps wash out the area causing an issue if it manifests itself. My hiking partner had no problems and continues to use the mix on everything. As a landscape architect he is in treated clothes almost everyday so I must be more sensitive to it.

[DGoggins]

I used the same product you have used and the same methods, except I doubled the solution. It was very effective, however, I did develop a rash on my wrists and ankles

Why not simply do a .5% solution instead of a 1% solution with the permethrin sfr and see if you get a rash?

[Brad Rogers]

You can send clothes to insect shield for them to treat with their process that lasts 70 washings. It's not cheap but for a couple of pieces it's not all that bad.

[John Vance]

Yes, I tried to back off the concentration levels and it appears that the sensitivity isn't to the permethrin, it's the other ingredients in the mix and most likely the solvents.

[Marko Botsaris]

OK, while I am almost always the one poo-pooing the alarmists on here with their occasionally overwrought and unscientific worries about chemicals – including in the past to people ranting on Permethrin – seriously? I use Permethrin all the time, but wouldn't want a neuro-toxin in regular contact with my skin, I don't care how impermeable it is to healthy skin, or how fast it breaks down. Also, I sincerely hope you don't have cats which are apparently highly sensitive to it. Having a big-assed concentrated container of it would also make me nervous. I guess everyone has a line somewhere on such issues.

Personally I'd stick to spraying it on the surface which is the only place it does any good. I wouldn't treat it so casually. I consider it the nuclear option only to be used when conventional deterrents are doomed to fail due to sheer numbers. And only on the outside of outer layer garments. Hopefully a skin rash will be the only side effect. Looks like enough of it may lead to the developments of parkinsons in mice. Probably I'm overreacting but…

[James Marco]

"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?"
Wetting is enough. But, the caveat is some cotton cloths, nylons, etc are steamed and pressed and may resist thorough wetting, soo, you are better off soaking. Cotton threads may be waxed. Nylons may be coated. Some plastics (PET style) that don't accept water are not subject to being treated with permethrin(a few exceptions.) Fleece is a common cloth that does not accept treatment. Polyester is usually not(PET is a type of polyester,) but you need to check each potential product, they can differ in characteristics and degree in which they soak water. Plastic films usually do not accept permethrin. If it does not, it will bleed onto your skin, and, into the environment. Not recommended for home testing. Soo, in answer to your question, soaking for an hour is guaranteed to work on anything that permethrin attaches to. But many (perhaps most) items can get by just fine with only wetting/drying provided the water/solution reaches everything. Some sprays may be bonded before all the fabric is treated, leaving only water to pass on to your inner pockets, for example.

2) Well, permethrin is like a dye. It loosely bonds with available molecules. When these are full, it will not bond. It just stays on the fabric. Rinsing will remove this excess and only a very small amount of the bonded material. You should NOT EVER USE A HOME/COMMERCIAL washer to rinse permethrin off cloths. The drain water is deadly to aquatic life. It is not caught by water treatment plants. You should dispose of this as toxic waste or use it around your foundation/floors to prevent insect infestations. You can also set it in a shallow pan on your sidewalk. Strong UV (sunlight) will break it down after a day or two. It doesn't matter if you apply a .5% solution or 10% solution, the fabric will only pick up so much from the dye bath. Once you reach this limit, it will not bond anymore. (Not quite true, temp, some other chemicals, pressure, may effect it.)

3) Micro-encapsulation??? I wouldn't bother…it is primarily marketing phrase for emulsifier. Some things bond better than others to permethrin. Cotton bonds very well but is not really great for cold weather camping. Nylon doesn't bond as well, but makes better clothing. Depends on what you are dying more than how you are dying it. Most common fleeces will not bond at all. It just washes out, like your ground cloth.

4) & 5) I think were answered. If you don't supply enough, you don't bond completely. If it never enters the material, it cannot bond.

You should be careful around cats. It is deadly to them, also fish and amphibians. You should not do your underwear or socks as a precaution. Only do the outside of your sleeping bag. You should not dump any liquids into any sewer or drain. Use sunlight to destroy it. (You can dump small amounts on your road or paved driveway in times of bright sunlight.) If it gets into the ground it stays there for many years, it is almost as bad as DDT. Once it is on your cloths, it will stay effective for about 50 washes. Crossing a stream does not wash it out. It does wash slowly, like the dye in your "T" shirt.

Don't take my word for it. Stop using it and study up on it.

[Barry P]

Wow. Everyone has different experiences with this.
“…flipping clothes over, etc.”

What is this? I hang my clothes on hangers— on a rope strung in the garage. Then it’s easy to spray both sides. I like spraying in the garage because then it kills all the bugs in the garage — for a couple of weeks. I spray with the garage door slightly cracked. After I’m done, I close the garage door and go to bed.

In the morning, I fold my clothes and vacuum/sweep up all the bugs.

I’ve done my “scientific” SFR experiments in May or June of 2006 in the MO Ozarks where tics are the worse I’ve seen. Since I’m a sandal backpacker I spray my socks. With Saywer and/or Permanone spray, at the end of the day, I easily pick out 300 dead ticks from my socks. The spray also lasts for a month. With my SFR dilution (and using more permathrin), I only killed a dozen tics on my socks; and I had to pull several off my legs. Even though Sawyer and Permanone have way less permethrin, it is WAY more effective on my clothes.

If there are any Sawyer side effects, I haven’t seen any. And if there were any, it would be extremely pale in comparison to lyme disease or rocky mountain fever.

May everyone kill tics.
-Barry

[James Marco]

Here is another article about permethrin:
http://sectionhiker.com/darn-tough-socks-with-insect-shield-make-your-own/

I don't care to do my socks because IFF you develop problems with permethrin, your feet will likely develop them first. But Philip does his…

[DGoggins]

Ok, update on my process over last year.

I didn’t like soaking and ringing out all of my families clothes like I did last year. So this year…I set out all of my clothes on my lawn, and used by tank sprayer to spray the clothes instead.

It took about 30 seconds to spray one side, then flip them over and spray the other side. I let them dry outside a bit, then hung them on a clothes drying rack to finish after a few hours. Then,…I put them in the wash to get rid of the residue and done! I found this to be extremely fast, easy, and convenient, especially for a lot of clothes.

Unlike where I soaked the clothes before…this time after they dried they didn’t stink quite as bad, and especially after the washing machine, much less smell compared to the soaking method (which made my whole house smell of the petroleum distillates). After they air dried the second time…no smell at all.

 

[Ryan K]

DGoggins, don’t you have to avoid drying them in the sun since UV degrades permethrin?

 

Interesting to hear how many dead ticks Barry pulled out of his socks.  My socks are so thin, I don’t think any could “hide” in them and die, unless they tried to bite through the sock with their last breath.

I’ve been on the fence about bothering with permethrin treatment.  If a fabric is bug-proof already so the mozzies are just bouncing along it trying to find an opening, do you really need permethrin to try to kill them?

The problem is I don’t think much that I wear will hold treatment for very long.  When it’s buggy, what I do now is put on thin crew-length socks (I normally hike without), wind pants with elastic cuffs, wind shirt, and when it’s really bad, going crazy with buzzing around my ears, I pull my S2S headnet (already with insect shield) over my old Goretex brimmed hat.  I don’t think my wind pants, wind shirt or hat would absorb much treatment.

So am I right that all I might benefit from is using some Sawyer spray on the outside of my socks above the shoe line, primarily to kill any ticks that might try to sneak up my pant cuff?

[James Marco]

I think you should rinse the clothing after they dry, in another bucket of water, then spill it on a road in bright sunlight. Do Not ever put it into a sewage system (as does washing excess off.) Do your homework before dealing with insecticides. We do NOT want another DDT disaster.

The rash you spoke of is likely from the petroleum (likely raw kerosene, with all the fractions in it. Kero, benzene like rings, several alkanes, alkenes, alkines, etc.) I would suggest rinsing in raw gasoline, then burning that in your lawn mower. (High heat/combustion will also break down permethrin. I do not know which one(s) are causing the irritation.) Let them dry again, then wash them.

Letting your clothing dry in sunlight removes some of the permethrin. But anything shaded from UV will be fine. Clothing is very thick compared to the molecular thickness of permethrin. Permethrin is basically “shaded” from sun for 99%(at a guess, probably much more) of it’s thickness. So, it really doesn’t matter if you hang the cloths in the sun or not. The loss of even a single percentage point is relativly unimportant. (it should last between 30-70 launderings.)

[Clue M]

I would think the surfactants would work to remove most of the effectiveness when washed, making the concentrate a false value.

The post above about ticks and sandals suggests the concentrate is largely ineffective versus the low concentration clothing treatments.

it may be completely unnecessary to handle concentrated neurotoxins to treat clothing.

[Kenneth Keating]

When spraying, is everyone also turning the clothes inside out and spraying the inside?  Along the coast here in Calif there’s lots of ticks, and I’m always concerned the permethrin doesn’t  soak through the pants enough and only remains on the exterior.  The ticks that are going to get you are the ones moving in the interior of the clothes so I spray the interior also to ensure I’m protected.

[Jerry Adams]

I just spray it on exterior

Part of the deal is the ticks don’t like the smell and stay off

I don’t like it on the interior because that’s against my skin

[Kenneth Keating]

Permethrin only works by contact, not by smell.  http://sawyerdirect.net/t/FAQPermetherin and  National Pesticide Information Center

Also, see below for a brief summary of the different kinds of blends.  This came from http://www.tickinfo.com/permethrin.htm.  I always wondered if the agricultural products would work because they’re so much more inexpensive.  But it looks like that’s not the case.

Not all permethrin is blended for the purpose of bonding to fabric.  Most permethrin is agricultural which is for pest control on vegetation.  Its design purpose is to stick to plants thus protecting the plants.  Veterinary products are designed to adhere to animal skins/hair or premises and are not for fabric application.  Some permethrin is formulated for treatment of medical conditions such as head lice and scabies.  The formulations are not interchangeable mostly because of solvents utilized.  Always refer to manufacturers label and follow instructions.

This site as quite a few good references regarding Permethin;

http://npic.orst.edu/pest/mosquito/ptc.html

[Jerry Adams]

Interesting links, thanks

okay, it’s not smell, but often ticks are repelled, not killed.  If the outside of the clothing has permethrin, then ticks will tend to stay off.

[DGoggins]

OK…..another update this year. For posterity’s sake..I wanted to correct my info that I put in this thread.

First….don’t use the 36.8% permethrin ….that stuff really does have petroleum distillates.

This year, I pretty much followed this article ->

http://sectionhiker.com/permethrin-soak-method-guide/

The 10% martin’s permethrin is good stuff. Stinks MUCH less than the 36.8% stuff I bought before. In fact, barely a smell at all….pretty much exactly like the normal permethrin stuff from Sawyers.

Second….you are right, you should not dry your clothes out in the sun. The UV degrades the permethrin.

So this time…I made half a gallon of solution and put it in a 1 gallon tank sprayer. So that was 3.2oz of solution and 28.8oz of water.

I was doing my family’s clothes…so 5 pairs of pants, 5 shirts, 10 pairs of socks, and my fleece beanie. Half a gallon was just right.

So, using the sprayer means I didn’t have to squeeze a trigger like using the Sawyer’s premixed stuff, and I also wouldn’t have to dunk clothes and wring them out, which is a pain too. So I sprayed them till wet, and then carefully placed them (I’m wearing latex gloves and long sleeve clothes here) in a black trash bag inside a 5 gallon bucket. With everything damp/wet, I had maybe 1/10th of a gallon left in the sprayer, so I dumped that in the bag and then sealed the bag.

So, everything is wet, mostly soaked but not soaked enough to require wringing out clothes to dry. I left the clothes set for 5-6 hours, and then carefully removed the clothes and set them out to dry in my garage during the night (no UV exposure).

Again, nothing smelled….I don’t think the 10% martin’s permethrin has any petroleum distillates in them (or if there are, its minimal).

So, after they dried, I did NOT put them in the wash, I just put them away like normal.

[Matt V]

I have some insectshield clothes, and the tag they add says how much permethrin they contain. I’ll have to check.

It does seem to make sense to wash clothes after treatment to get rid of residual permethrin that’s not bonded to the fabric, so that it doesn’t wash off in the environment or on your skin. Hand washing in a bucket then dumping that solution out would be best. If it lasts for 70 washings, then washing it once isn’t going to have a big effect on the amount of permethrin in the clothing.  If it only lasts six washes like the Sectionhiker article says or like Sawer spray then washing once after treatment would not desirable.

I have a bottle of Martin’s I haven’t used yet. I am a little worried about skin sensitivity, so I’ll have to test it on one piece of clothing to start with. At least one person in the Section Hiker article has reported sensitivity using Martin’s. I can’t think of anyone reporting sensitivity to Sawyer or Insectshield.

I’m also concerned that we don’t have any good way to tell how long these DIY treatments last or how effective they are. I don’t want to think I’m protected then end up with ticks and mosquitoes. I’ve had a few mosquito bites through my Insectsheild treated hiking shirt. It has a very open weave, but I would still expect permethrin to repel and kill anything that lands on it. Yeah, I can still use insect repellent, and I probably will for an extra layer of defense against ticks, but if a shirt can’t even repel or kill mosquitoes then how do I know it works at all?

[DGoggins]

The way I understand it…is that permethrin is not a repellent at all. It is a pesticide.

So, citronella is a repellent….mosquitos don’t like the smell. DEET is a repellent….it masks human odor and carbon dioxide emissions from humans so mosquitos can’t detect that you are “there”.

Permethrin doesn’t do that….if a tick goes on your clothing, while it is attached to your clothing they die after a while due to the permethrin. Same thing with Mosquitos…they will land right on the clothing, and if you have a high pore material they will bite right through it, and fly away. Most likely to die from the permethrin effects, but….the damage was already done to you (you were bit).

So, permethrin is pretty much just a tick weapon. You need high weave long sleeve garments (tight weave 100% nylon) that mosquitos can’t bite through, with DEET/picardin on exposed skin. I just switched to crew length socks, so that just leaves the back of my hands and face. But…my hat covers most of my neck and a lot of my face, so I normally don’t put on any DEET…if a mosquito is buzzing my face I’m swatting at them anyway, and I can watch my hands. I’m not in alaska though (mountain west) and mosquitos aren’t awful most of the time. I just trust my clothing if I’m sitting down…its a bit unnerving to have a couple of mosquitos on pants/shirt but I try not to swat at them….I hope the permethrin will kill them eventually when they fly off.

[Matt V]

Sawyer seems to advertise it as a repellent in addition to a pesticide.

Some interesting info from the Sawyer website:

In studies performed by the U.S. Army, about 20 to 30 percent of the permethrin treatment was removed after the first laundering. Thereafter, about 3 to 5 percent was lost to each cycle through ten launderings.

 

 Sawyer Permethrin Insect Repellent can be applied to dogs and help control mosquitoes, ticks, and fleas for 35 days.

 

Do not expose cats to wet permethrin as it affects their central nervous system. This is not true with dogs, horses, or cows. Cats can be around permethrin treated fabrics once the application has dried.

 

The more permethrin molecules in the area the greater your overall protection. Treating your shirt and pants is much more effective than just treating one of the garments. Also treating your back pack significantly adds to the protection from your shirt and pants.

 

 

 

[Jerry Adams]

I wear long pants and shirt

If mosquitoes bother, I put DEET on the back of my hands, on my neck, forehead, ears

One tube of DEET lasts forever

I have read permethrin kills bugs, but also repels them

Sometimes I encounter these biting flies.  They aren’t bothered by DEET.  Then, it’s Peter’s headnet.

[James Marco]

Permethrin is a nerve poison to insects, most reptiles, amphibians, fish, and a few mammals…cats most notably. Few people are allergic to it, but try a small sample fist, to be on the safe side. It is NOT a replant. But, even a mosquito knows it is being killed and will fly off. DO NOT DUMP EXCESS. Either down a drain or through washing!!! It can last for years in the ground (good for insect control around foundations) and it flows right through a sewage treatment plant unchanged. You can pour any excess and any rinse water onto a road or in your driveway where UV can break it down.

If you do it at home:
1) treat your clothing (skip your underwear and socks)
2) let them dry
3) Rinse excess out in a 5 gallon bucket (remember, do not dump on ground or in a drain)
4) Rinse a second time
5) wash normally

OK. Site editor screwed up again. Hope you got it. This software is getting real bad.

[James Marco]

Note that the much higher concentrations allowed by the MYOG method lets it last 30-70 washings. Loss of a bit during the rinses do not effect this. Now does it wash out like Sawyer’s does.

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