New Insect repellents recommended by CDC

charlos said:

anyone have anything to say about permethrin?
been using it on my clothes and some gear for a couple of years now with great results.

suprised not to see it mentioned in this thread, through my research it seems safe if you follow precautions correctly.

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I use it too, seems to work. Not showing any signs of toxicity so far...

All sorts of info available via a search:
http://www.google.com/search?hl=en&q=permethrin&btnG=Google+Search

One hit on its safety:
http://pmep.cce.cornell.edu/profiles/extoxnet/metiram-propoxur/permethrin-ext.html

An FAQ:
http://www.travmed.com/trip_prep/insect_permethrin.htm

Doug

DEET is a dilution of a substance -- I think a defoliant -- invented by the military.

The 30% works part time, on lesser insects. 100% is best for black flies. In the past, I had seen a product that had a different odor. However, I believe the odor may have something to do with its repellency.

Moose

Why do you think they call it dope?

moose_mckenzie said:

In the past, I had seen a product that had a different odor. However, I believe the odor may have something to do with its repellency.

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You probably mean Woodsman Fly Dope, which I used a lot in my youth. I'm not sure what's in it, or how it works compared to DEET, but it sure has a distinctive smell.

Repel Lemon Eucalyptus
This stuff works,and it's all natural. Just be careful using it on your face,particularly near your eyes-yow!
Needs to be applied more frequently than DEET based stuff,but seems safer to use continuously. From experience,great for black flies and mosquitos.

Shelf Life of DEET

Does anyone know the shelf life of DEET? Should I throw out last year's bottle and get a new one, or will it still be just as strong?

moose_mckenzie said:

DEET is a dilution of a substance -- I think a defoliant -- invented by the military.

The 30% works part time, on lesser insects. 100% is best for black flies. In the past, I had seen a product that had a different odor. However, I believe the odor may have something to do with its repellency.

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No, DEET is a solvent. (Relates to why it can dissolve some plastics.)
It is not a dilution in itself, but is available in many strengths (dilutions). 100% is presumably pure DEET.

Comments on efficacy in
http://content.nejm.org/cgi/content...IRSTINDEX=0&journalcode=nejm&journalcode=nejm

A nice summary at http://www.ces.ncsu.edu/depts/ent/notes/Urban/repel.htm.

Agree with Tramper Al--the repellent with a strong odor was likely Woodsman's. Don't know of any scientific tests on its efficacy at repelling insects, but it sure worked on many humans...

Doug

DougPaul said:

100% is presumably pure DEET.

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Althought it would be logical, I don't think this is so. If you look at the ingredients list of bug dope, I think it is 100% of active ingredients. Most of the stuff in the bottle is just filler.

There may be a confusion with Agent Orange leading to the defoliant idea. Both DEET and Agent Orange were developed by the Army for use in Vietnam.

The aroma of Old Woodsman's is sure to bring a tear to your eye and a gag to your stomach. But I don't think it has anything to do with repelling mosquitoes, as DEET works on confusing the bugs' ability to detect C02, not their ability to smell you. I'm not even sure if they smell humans.

-dave-

David Metsky said:

Althought it would be logical, I don't think this is so. If you look at the ingredients list of bug dope, I think it is 100% of active ingredients. Most of the stuff in the bottle is just filler.

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Disagree here--the advertised percentage of DEET is of the total. For example, I just checked REI Jungle Juice 100 insect repellent: 98.11% DEET, 1.89% other isomers. DEET is an organic solvent--that is why the high percentages feel so greasy.

From http://www.epa.gov/pesticides/factsheets/chemicals/deet.htm
"Formulations registered for direct application to human skin contain from 4 to 100% DEET."

as DEET works on confusing the bugs' ability to detect C02, not their ability to smell you. I'm not even sure if they smell humans.

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Perhaps this is delving into semantics, but in my book if an organism can detect an airborne chemical emitted by a second organism, the first can smell the second.

According to http://www.annals.org/cgi/content/full/128/11/931, (section "Stimuli that attract mosquitoes"), mosquitoes can detect CO2, lactic acid, moisture, and heat--all of which are emitted by the human body. It appears that DEET blocks the chemoreceptors for at least some of these stimuli.

BTW, this reference, "Mosquitoes and Mosquito Repellents, A Clinician's Guide" http://www.annals.org/cgi/content/full/128/11/931, is a worthwhile read.

Doug

DougPaul said:

mosquitoes can detect CO2, lactic acid, moisture, and heat--

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Sounds like the ingredients for a smelly, tired hiker. Dinner with a view.

DougPaul said:

Disagree here...

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I'm guessing that you are right. Bad memory followed by quick fingers, a bad combination.


-dave-

Here is another link on bug dope that just came my way.....

http://www.afpmb.org/coweb/guidance_targets/ppms/Repellent_Guidance.pdf

authored by:

LISA L. O'BRIEN, Ph.D.
MAJOR, US ARMY
DPMIAC/AFPMB
Walter Reed Army Medical Center
Washington, DC 20307-5001
URL: http://www.afpmb.org