Permethrin Treating

**Boris Losdindawoods** · 08-13-2010, 05:11

Originally Posted by LostCause

I understand you wanting to clear the air about permethrin not being as bad as everyone thinks it is, but most people will be cautious about it because it kills bugs.

Totally agree.

Originally Posted by LostCause

KILLS bugs and usually something that kills one thing will kill another. I'm not saying the stuff is safe either, but it's defiantly not as toxic to humans as it is to bugs or cats.

Humans and bugs have completely different metabolisms. It's impossible for permethrin to effect people in the same way that it effects bugs. Permethrin isn't not toxic at all to humans unless you drink it in high concentration and then it's only listed as "Likely to be Carcinogenic". Nobody has ever been able to find an actual link.

I hadn't meant to sound like I was saying "don't wear gloves". I was saying to read (and worry about) all of the other ingredients that we normally ignore.

I was mostly joking about embedding the permethrin in the sil tarp. Permethrin doesn't repel or effect the bugs until they touch the treated item. I don't really care about bugs on my tarp other than maybe an entire army of ants, and treating the tarp won't really keep me much safer from mosquitoes. I definitely do the bugnet though because I hate laying there watching the little buggers trying to get in!

Boris

**LostCause** · 08-13-2010, 07:32

Originally Posted by Boris Losdindawoods

I hadn't meant to sound like I was saying "don't wear gloves". I was saying to read (and worry about) all of the other ingredients that we normally ignore.

Totally agree with you on that point.

I was mostly joking about embedding the permethrin in the sil tarp. Permethrin doesn't repel or effect the bugs until they touch the treated item. I don't really care about bugs on my tarp other than maybe an entire army of ants, and treating the tarp won't really keep me much safer from mosquitoes. I definitely do the bugnet though because I hate laying there watching the little buggers trying to get in!

Boris

Actually while doing some reading on permethrin, I ran across a study done either by the army or for the army that listed that they had to move the test location because all the permethrin coated materials had kept the skeeters away from the test site nulling the test. Just having it on the tarp may prevent them from flying under it to begin with. It's something I'd be willing to test at least.

**Boris Losdindawoods** · 08-13-2010, 07:52

Originally Posted by LostCause

Actually while doing some reading on permethrin, I ran across a study done either by the army or for the army that listed that they had to move the test location because all the permethrin coated materials had kept the skeeters away from the test site nulling the test. Just having it on the tarp may prevent them from flying under it to begin with. It's something I'd be willing to test at least.

COOL! I'd love to see that if you ever find it again. That's a completely different use and a great illustration of how even different bugs react differently. Most spiders can't even tell the permethrin is there after it dries, but it still kills them. If it will keep the nasties away, I'm going to have to go buy another bottle!

I realized the other day that I have a set of tree huggers that definitely seem to be permethrin free. I don't bother to soak my huggers since the suspension lines are treated, but I always assumed the huggers had some permethrin on them from residual contact in the bag or something. I took my huggers off a tree earlier this week and there were at least hundreds of tiny ants, possibly 1,000+ that were just hanging out under the hugger. There was a solid mass of ants all the way around the tree in a perfect stripe to match the hugger. It was really weird. There weren't more than a dozen or so actually on the hugger, but you literally couldn't see the tree bark through the mass of ants. While I was standing there with my mouth hanging open, they all just sort of started wandering off. There was no mass panic when I exposed them and it wasn't like they went rushing away. Really kinda creepy. Now that I think about it, it's also weird that they were all on the bark and almost none of them on the hugger.

I dunnooooooo....

Boris

p.s. anybody gonna bust me on referring to spiders as bugs? I'm pretty sure my son is twitching in his sleep right now at the psychic insult of my inaccuracy.

**Just Jeff** · 08-13-2010, 08:03

Originally Posted by Boris Losdindawoods

Permethrin on the skin is totally metabolized by humans in 15 minutes.

Just want to clarify for folks who may not be familiar with permethrin...it's poisonous to people. DEET is used on skin, and absorbed into the body so it doesn't sweat off (though it does "wear out" over time and need to be reapplied). But permethrin is designed to be used on clothes and gear...even if it's "metabolized" into your body, it will make you grow extra digits or maybe give you super powers. Slight exaggeration, but still...you don't want to go around metabolizing permethrin!

**LostCause** · 08-13-2010, 08:56

Ok. I found a few references to it, but didn't find the actual study. It was actually the Air Force, not the Army. (My apologies Just Jeff. I didn't mean to confuse the two.

)

During testing in the Everglades, "Mosquitoes were also repelled because of the side-stream effect caused by numerous treated uniforms within the same general location. This required that the test site be moved to locate more mosquitoes!" Now that's performance . . .

Link to page here.

I have also found sites that refer to it as only a contact insecticide and not a repellent. Link to page here.

There was one other study that was done that I can remember that references permethrin as a repellent, but I can't remember or find the reference right now. I'll keep looking.

**Boris Losdindawoods** · 08-13-2010, 10:13

Originally Posted by Just Jeff

permethrin...it's poisonous to people.

No offense, but says who?

Our oldest daughter got scabies on her back about 3 years ago, and the doctor prescribed 5% permethrin cream. That's why I spent so much time investigating it and trying to figure out if we'd eventually have grandkids with gills. The CDC suggested treatment for scabies is a 5% permethrin scabicide cream (FIVE percent, not 0.5%) applied to every inch of your body from the neck down and left on overnight. For babies the CDC says, "In addition, when treating infants and young children, scabicide lotion or cream also should be applied to their entire head and neck".

To quote the link that LostCause just provided, "Permethrin is virtually non-toxic to humans and no systemic effects have been reported. In EPA and FDA tests, it was uncommon to have any skin reddening, rash or other irritation."

The report from the U.S. Environmental Protection Agency dated 12/9/2009 and titled Chemicals Evaluated for Carcinogenic Potential lists permethrin as "Likely to be Carcinogenic to Humans". Before anybody jumps up and yells "Ah-ha!", it helps to know what that means to the EPA. There are 5 possible criteria for the "Likely" designation:

an agent demonstrating a plausible (but not definitively causal) association between human exposure and cancer, in most cases with some supporting biological, experimental evidence, though not necessarily carcinogenicity data from animal experiments;
an agent that has tested positive in animal experiments in more than one species, sex, strain, site, or exposure route, with or without evidence of carcinogenicity in humans;
a positive tumor study that raises additional biological concerns beyond that of a statistically significant result, for example, a high degree of malignancy, or an early age at onset;
a rare animal tumor response in a single experiment that is assumed to be relevant to humans; or
a positive tumor study that is strengthened by other lines of evidence, for example, either plausible (but not definitively causal) association between human exposure and cancer or evidence that the agent or an important metabolite causes events generally known to be associated with tumor formation (such as DNA reactivity or effects on cell growth control) likely to be related to the tumor response in this case.

The only one of these 5 that I've ever been able to find in a report on permethrin is #2, the animal one. That study was done with mice (which I'm not suggesting invalidates it) and it was done with heavy oral doses. I can't remember the exact quantities, so I'm not going to risk giving incorrect numbers, but I remember calculating that I could drink a full bottle of the Sawyers permethrin mix without getting a one-time dose equal to the daily dose they were giving those mice.

So, yeah. It's "likely" to cause cancer if you EAT it in large doses. Other than that, all I can find in my research is a lot of undocumented fear mongering.

Boris

**mtncmpr** · 08-13-2010, 10:35

.

Boris,

I THINK I understand where you are coming from. You aren't saying you feel directions don't need to be followed while using the Permethrin solutions (as discussed here) used to treat gear, are you?

.

**Boris Losdindawoods** · 08-13-2010, 14:32

You should ALWAYS follow the manufacturer's directions.

All I'm saying is that "Permanone" is not permethrin.
"Sawyer Premium Insect Repellent" is not permethrin.

Those are both products which contain permethrin along with other stuff. That other "stuff" is what causes all of the warnings. That last statement is not my opinion, by the way. It's exactly what Sawyer told Crankybear. The Sawyer aerosol product uses mineral spirits to help get an even distribution of the permethrin. Mineral spirits are not something you want in your eyes, your lungs, or on your skin for too long. That has absolutely nothing to do with permethrin. If Permanone is bad for your skin, that doesn't mean that permethrin is bad for your skin.

The great state of California has to be our nation's most ummm... vigilant? state when it comes to carcinogens and such. Check out their report on Permanone. Their comment about the original formula of Permanone cracks me up. "Severe irritation was seen with the formulation which was attributed primarily to the inert ingredients." Oops. Somebody had to lose their job over that one. That's why they reformulated Permanone.

California determined that the theoretical risk for excess cancer was approximately 1 to 3 in 100,000 assuming LIFETIME use of permethrin treated clothing. California also determined the MOS (margin of safety) for various effects of permethrin:
Acute neurological effects - over 200
Acute dermal irritation - over 2,000
Dermal irritation - 100 to 400 (different use scenarios)
Liver hypertrophy - 200 to 200 (different use scenarios)
Liver hypertrophy and alveolar cell proliferation with chronic exposure - over 700

If the MOS is 100, then you can "overdose" by 100X before you get to a dosage that they've determined will actuall have any observable effect. That's not 100X and then you fall over dead. That's 100X and then there will be a statistically observable effect within a subject pool.

Like I said before, I had a teenager who was being told to smear this stuff all over her body and I'm fairly fond of her most days of the week (sometimes for a week or two straight) so we checked it out. My wife is a nurse whose masters degree is in research and education so we're all about "what does the data actually say?"

The data says that permethrin isn't bad for you in any reasonable dosage. The junk they mix in with it can be really bad for you and might even eat your sil tarp. I'm way too cheap to buy a sil tarp, so I just slather permethrin on everything.

Boris

**BillyBob58** · 08-13-2010, 15:24

Thanks for consistently providing all these Permethrin facts, Boris. They have certainly made me feel much more at ease about spraying my hiking clothes. Which I did any way, despite slight anxiety, because I felt the greater risk was tick bites and mossy bites and West Nile fever. And also because it was such a superior experience to using DEET. Deet was very unpleasant for me, and the mossies or other insects would still buzz in my ears, even if they didn't bite. They don't seem to come near my ears if I have my big floppy Permethrin treated sun hat on.

I also now feel more at ease about spraying my yard with Permethrin. In fact I am about to get up and spray it again. It has been 3 weeks or more since last spraying, and I've notice a few mossies the last day or two.

Also, I'm still a big fan of 15% Picaridin. By itself or along with Permethrin treated clothes. It seems to keep the bugs away pretty good, though I haven't done any hard core scientific comparisons with DEET. But I dom't mind spraying that stuff all over me, and my clothes if no Permethrin has been applied. It has a tolerable smell while applying it and after a few minutes, no smell at all. Between the two I have not needed DEET in a couple of years now. And that says a lot in MS! I have not been able to find the Sawyer 20% Picaridin, or any other 20%, so I am going to break down and order some one of these days. I did find the Sawyer non-aerosol spray on 24 oz .5% Perm at ****'s and got some.