permethrin re-treatment
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jeffrey armbruster
(book) - M

Locale: Northern California
permethrin re-treatment on 02/15/2011 10:21:11 MST Print View

So I treated a Patagonia capilene base layer with Permethrin last June--the soak-in-a-bag super duper treatment. Manufacturers say that it will last 50 washes. I've only washed this layer about four or five times since the treatment. What do you think: is it ready to go for next season, or do I need to re-treat?

Actually, I may just try to use my new Houdini windshirt as a mosquito shirt and leave it at that.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: permethrin re-treatment on 02/15/2011 12:31:50 MST Print View

Hi Jeffrey,

It should be good to go for several more seasons, based on that level of usage. You'll be able to tell for sure once you've watched a few mosquitoes alite.

Cheers,

Rick

jeffrey armbruster
(book) - M

Locale: Northern California
permethrin re-treatment on 02/15/2011 13:09:23 MST Print View

Thanks, Rick. That's pretty much what I've guessed. Yeah, it's my dedicated backpacking base layer, so it's just once in the washer at the end of each trip--I'm not sure if rinsing in a lake and hanging to dry counts as a wash...

is your insight based on your own experience?

Ben 2 World
(ben2world) - MLife

Locale: So Cal
Re: permethrin re-treatment on 02/15/2011 16:41:55 MST Print View

Jeffrey:

Can you tell us the brand? I've been using Sawyer spray on -- available at both Wally World and REI -- but it's only good for a few washes. Maybe your "super duper" soak will save me some money.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: permethrin re-treatment on 02/15/2011 16:49:15 MST Print View

Benjamin, last summer I used Coleman Gear & Clothing Insect Treatment (permethrin spray) on some clothing that I wore in Alaska. I didn't know how effective it would be, so I really soaked the spray into the fabric.

When in Alaska, the odor surrounded me for two weeks. I was glad to get home and get into normal clothing. It is not a terribly bad odor, but it gets old after a while.

--B.G.--

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
re on 02/15/2011 16:57:33 MST Print View

I've used spray-on Sawyer

So much easier to use - just hang clothes, spray on, wait 24 hours

And 1 bottle lasts a lifetime, so it isn't expensive (that is the lifetime of that chemical solution, whatever that might be).

I spray it on boots, gaiters, and pants for ticks, but I don't really know if it's effective.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: permethrin re-treatment on 02/15/2011 17:19:46 MST Print View

Hi Jeffrey,

Yes, I've found the treatment lasts years so long as applied well to begin with. Immersion seems more thorough than sprays--my other concern is not to let any overspray or drips loose in the environment.

Cheers,

Rick

Edited by halfturbo on 02/15/2011 17:20:38 MST.

peter vacco
(fluff@inreach.com) - M

Locale: no. california
permethryn on the cheap ... and often. on 02/15/2011 19:03:51 MST Print View

you can find 36.8% permythrin on amazon out of texas. not only does it kill bedbugs (a good thing, but malathion is better), but this then lets you take only an oz or so of concentrate on a very long trip, and just keep making new 1 or 2 oz spray bottles up as you go.
is sorta like having as much as you want.
sawyer's is only 0.5%. which is one half a part out of 100.
i re-spritz the hat and shoulders every day or so. it can't hurt, and the bugs die so much faster.
i suspect that spraying poly treated tent flys will make them leak faster. that said, you can not put too much of this stuff on a backpack.

those inclined to trust the governing bodies will not buy malathion Right Now. the more enlightened might be well advised to nab maybe 8 pints while they can still get it without a license. $7.96 at home despot and lowe's.
chicks dig oozing sores on your arms.
bedbugs are fun.

v.

John Nausieda
(Meander) - MLife

Locale: PNW
permethrin re-treatment on 02/15/2011 19:20:01 MST Print View

You may want to check out the acute dermal toxicity of the chemicals you are playing with. Malathion and Permethrin are very different.This is all about the way neurotransmitters in mammals and insects are interrupted. Permethrin is pretty lethal to cats. Rotenone which used to be recommended as an organic pesticide is linked to Parkinson's this week nationally. And I'm sorry but washing your Caprilene in a lake is not good for those who live in it or who come after you.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
re on 02/15/2011 19:23:24 MST Print View

If you spray permethrin on the outside of the fabric and then let it dry, are you subject to its poisonous effects?

What about if you soak the fabric and then let it dry?

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
permethryn on 02/15/2011 19:46:26 MST Print View

Hi Jerry,

I'd avoid breathing the aerosol itself. Permethryn isn't volatile so you won't be breathing it while it's drying. Despite low dermal absorbtion I'd still handle with gloves. I'd prefer to spray clothing in a "spray box" to capture as much aerosol as possible, and if dipping, capture all the drips.

Dispose in the garbage rather than washing down the drain.

Cheers,

Rick

jeffrey armbruster
(book) - M

Locale: Northern California
permethryn on 02/16/2011 15:06:04 MST Print View

Benjamin and others: I can't remember the brand right now; bought it at REI. As I said, I did use the soak method, which is advertised to last longer.

In my experience, the permethryn did not visibly "kill" any mosquitos; in fact, they landed on my shirt but did not seem to bite. They'd just fly off.

Also, I hate deet, esp. the smell. Permethryn seemed so much more preferable precisely because it had no smell at all. Still, I was/am concerned about health effects. So far, science seems to stand behind this product. I tend to stand behind science. But not always.

As to rinsing my shirt in a lake: really? This is poisoning the environment? I wring it out on shore...honestly, stepping in a slightly wrong spot by the shore of a creek, for example, before crossing; or for that matter, merely crossing a creek, must cause far more degradation than dipping my shirt in water...my point is, glass houses and all. I refuse to be guilt tripped by this.

John Nausieda
(Meander) - MLife

Locale: PNW
permethrin re-treatment on 02/16/2011 15:31:19 MST Print View

Effects on Aquatic Organisms
Permethrin is toxic to fish and should be kept out of all bodies of water (1). It was highly toxic to fish in laboratory tests, but showed low toxicity in field tests (23). Aquatic ecosystems are particularly vulnerable to the impact of permethrin. A fragile balance exists between the quality and quantity of insects and other invertebrates that serve as fish food (2).

The LC50 for rainbow trout is 12.5 micrograms per liter (ug/l) for 24 hours, and 5.4 ug/l for 48 hours (7). The LC50 for 48 hours in bluegill sunfish and salmon is 1.8 ug/l (2). As a group, synthetic pyrethroids were toxic to all estuarine species tested. They had a 96-hour LC50 of less than or equal to 7.8 ug/l (15).

Breakdown of Chemical in Water
The results of one study indicate that synthetic pyrethroids can present a significant threat if they are used near estuarine areas. They tend to bioconcentrate in these environments. In this study, permethrin had a half- life of less than 2.5 days. When exposed to sunlight, the half-life was 4.6 days (15). Permethrin should be kept out of lakes, streams, or ponds. Do not contaminate water by cleaning equipment or by disposing of wastes near a body of water. Permethrin may not be applied when weather conditions favor drift from treated areas (1). Permethrin degrades rapidly in water, although it can persist in sediments (7, 21). There is a gradual loss of toxicity after permethrin ages for 48 hours in sunlight at 50 parts per billion (ppb) in water (14).

If you would take some water from a lake and wash and rinse your shirt away from the lake the chemical will bind tightly in the soil and not be a problem.

peter vacco
(fluff@inreach.com) - M

Locale: no. california
ohh yeah.. they're dead ... on 02/16/2011 19:49:03 MST Print View

"In my experience, the permethryn did not visibly "kill" any mosquitos; in fact, they landed on my shirt but did not seem to bite. They'd just fly off"

no worries, they do fly away. and then they die. guaranteed. in fact the moment they touch the stuff they are compromised and won't complete their mission in life.
you can watch this amazing transformation of nature right in your tent (if you have a tent). the bugs will pack in there while you have the door open, and, if you have the interior good and douched down with prmthy, the bugs will zing about, thinking about eating you, but then, they will soon fly stupid for a bit, losing altitude as they go, until they are buzzing in death circles on the floor.
a spritz in the air knocks them down. they do not expire immediately. but they won't bother you anymore as they are circling the drain.
i don't enjoy killing things, but i really don't enjoy getting bit quite a bit more.
but it's just mosquitos, and trust me, where those came from, there's always .. more.

if you treat the underside of your hat brim, the occasional ones that leak in under the net won't be able to score.

cheers,
v.

Will Webster
(WillWeb) - M
Re: permethrin re-treatment on 02/17/2011 05:49:17 MST Print View

Permethrin bonds well enough to fabric that it remains effective after several washings in warm water with detergent. The amount that will be released from dipping into a lake has to be minimal. No, you shouldn't apply it next to a waterbody or wetland, or dispose of the soaking solution irresponsibly, but that's completely different from rinsing out a shirt.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: permethrin re-treatment on 02/17/2011 07:35:03 MST Print View

Permethrin acts as a dye on many articles of clothing. Cotton, nylon are good examples. Polyester is not so good. Soo, it is hard to say without knowing the actual composition involved. Basically it forms a loose hydrogen bond. Water alone will leach a bit out with each washing. How much depends on the material used in the clothing. People, have a high resistance to it, but, you really shouldn't use it on underclothes or socks. More of a caution, than anything else. Like anything else, some people can be allergic to it. Depending on the exact chemicals in the water (alkaline and acid) water solubility can change a bit as does the degree of leaching. As with a lot of dyes, a stronger dye can replace a weaker dye. Soo, it may not be effective on some cloths, simply not bonding enough to be very effective and much more easily washed out. Blaze orange is one that does not pick up permethrin well.
Generally, dipping a shirt in the lake is fine. But, it should NOT be allowed to drain back into the lake. Walk back into the woods before squeezing any excess water out. Scatter the water a bit, do not bury it.


It degrades in sunlight, not sure which wavelength's, but I suspect it is the UV ranges, the higher energy ones. After washing, most water treatment plants will churn water allowing sunlight to get to the water...soo, most if not all, of the permethrin is degraded. However, untreated leftover wash water should be cared for responsibly. As others have pointed out, it bonds with many organics in soils fairly solidly, but, use it with caution. They said the same for DDT. It CAN poison soils for a long time if not exposed to sunlight. It is naturally occurring in some flowers. See: http://en.wikipedia.org/wiki/Chrysanthemum.

It is deadly to fish and bugs. I use stuff sold as "ant killer." It is primarily oil soluble, soo, higher concentrations are often found in solutions of kerosene or other petroleum based product.

It takes very little to treat items. Wash and spin dry. Mix a desired concentration (I usually toss in about 1/4 cup of dry mix at ~.5%) and a half to one gallon of water in a large
ziplock...2 gallon size if you can get them...or a bucket. Then add a pair of pants and shirt. Preferably, in a larger, open area where you do not want ants or other bugs (grubs, etc.) Let them sit in the solution about 1/2 hour and remove them, wringing them out as you go. (You ARE wearing gloves, of course.) Hang them and let them dry thoroughly. Then wash them again without detergent, drying normally. You are relying on the waste treatment plant to destroy the remainder in the wash water. The excess in the bucket can be used for treating anything that you like. Your hat, shoes, pack, etc. It will keep bugs down. The rest should be scattered on the open area you were working in. Let the sunlight get at it. Or leave it in the bucket in the sun for a few days, then scatter it on the driveway. Either way the sun will destroy the remaining permthy in the solution. DO NOT let it run off into a storm drain if you live in a city.

Basically, the concentration reduces with each application to cloths. It has an affinity to fabrics, so the initial concentration doesn't much matter. If you have enough, the rest is excess. It will reduce a lot the first time, quite a bit the second time, gradually reducing, but never quite reaching 0%. I like to think of an exponential scale, but this is not 100% accurate. But, trying to retreat clothing that was freshly treated MAY reduce the amount of permthy in the cloths, since you also wash out some. This is equilibrium. Depends on the concentration and the type of clothing. I won't pretend to be able to calculate these numbers, my chemistry is very old...though not as old as I am getting... Mostly, I just "eyeball" things these days...

The concentration on the cloths will be enough to kill most mosquitoes within 12 hours. And it will deter them from biting, but not from swarming. It does NOT have a very high vapour pressure, hence, doesn't form a "cloud" of resistance around you. Blackflies and Mosquitoes are my primary blood suckers in the ADK's. These are both attracted to IR and CO2. Black flies want open skin to chew on and they swarm. Very annoying. Permthy doesn't help much, 'cept to know I got revenge. Mosquitoes are a bit different and will bite through clothing. Permthy helps a lot. I use it in conjunction with DEET. This seems to keep the worst of the pests under control. Often, in May, I have been in the ADK's on a canoe trip and only gotten one or two bites in a week. Really Excellent coverage. It does NOT help with swarming and buzzing...but I think that may be in my head from the permthy.

I do NOT recommend this to anyone. As with any highly toxic substance, you have to know more than just a smattering of info. To me, it outweighs the risks of all sorts of insect born illnesses and the annoyance and possible infections of bites. You should study up on it and decide for yourself if it is worth it. It can cause nervous disorders, and may be related to an increased incidence of Parkinson's.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
re on 02/17/2011 08:53:14 MST Print View

It seems like if you just spray the outside of the fabric you'll get the benefits and minimize problems.

Less permethrin against your skin

Less excess washed away into the sewage treatment plant

I use it against ticks - boots, gaiters, and long pants

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: re on 02/17/2011 09:46:17 MST Print View

Jerry,
I am not sure about the sprays. They may not include enough water to promote the dying action of the permethrin. It could wash out very fast if not allowed time to penetrate the fabric fibers before rinsing...as in a rain. Just a thought...

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: re on 02/17/2011 09:58:45 MST Print View

The instructions say to spray for 30 seconds to thouroghly wet surface

If you do the bath treatment, most of the permethrin just sits there in the water

They wouldn't sell it if it wasn't effective, would they???

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: re on 02/17/2011 10:54:56 MST Print View

"They wouldn't sell it if it wasn't effective, would they???"
Jerry,
Ha, ha, ha, ha, .... You have got to be kidding me...