Going climbing this weekend in a place notorious for mosquitoes. I anticipate most if not all of my climbing buds will be slathering on the DEET. I've seen DEET eat through a plastic bag before and was wondering if anyone knows what DEET does to the nylon used in ropes, runners, etc.

Thanks a bunch!

Nylon is one of the few things that DEET won't destroy.

Just curious, but what materials does DEET destroy?

3m Ultrathon cream is the only DEET based mosquito repellent to buy. It is a lotion based, and doesn't dilute in sweat. Its also what the international Travel docs recommend for travel to places with malaria. The biggest problem with liquid DEET sprays and synthetic material is staining them some color other than their original. Seen it happen on polyester clothes before.

Hey Mike,

Got this from a brochure from the University of Florida:

Only apply DEET formulations to exposed skin;
do not apply to areas underneath clothing. DEET will
damage plastic materials, so do not apply DEET
formulations on or near plastics, acetate, rayon,
Spandex, synthetic fabrics (other than nylon),
furniture finishes, leather, watch crystals, and painted
or varnished surfaces. Plastic glass frames and
goggles should be protected from DEET applications.
Car finishes and interiors also may be damaged by
DEET. It will not damage nylon, cotton, or wool
fabrics.

JWong - thanks a bunch for your post. I will climb with peace of mind this weekend, even with all the DEET oozing on to my gear. Here's the link for the rest of the community to read: http://edis.ifas.ufl.edu/IG122

Nathan - ditto on the Ultrathon, the best stuff around for climbers.

remember that lot of modern climbing gear soft goods are no longer nylon, but rather spectra or a similar derivative...

Good point Avery. Here's some info on DEET and Spectra poached from a climbing.com thread. All the info suggests that DEET will not weaken nylon, spectra or dyneema.

"http://www.sterlingrope.com/2005/climbing_techtips.asp#chemr>>>>>
Samples of nylon, polyester, and spectra were submitted for chemical resistance testing for DEET (N,dimethyl-m-toluamide). The three samples were immersed separately in "CUTTER" and "OFF" brand insect repellent for a period of twenty-four hours at room temperature. "OFF" contains 95% Deet (N-dimethyl-m-toluamide) while "CUTTER" contains only 7% Deet and probably some oil based solvents as well. The results of the testing indicate no loss of strength as measured by tensile strength retention in any of the three samples.

There was one interesting anomaly that occurred only in the case of Nylon and the "CUTTER" brand insect repellent. As mentioned before there was no loss of strength for any of the samples but here there was a 25% increase in the elongation and a decrease in modulus. This basically means that a rope made entirely or mostly out of Nylon may become "rubbery" with a significant amount of exposure to "CUTTER" or other insect repellents with large amounts of oil based solvents.

However, with regard to the chemical in question, DEET, there appears to be no effect on any of the physical properties of the three samples. Hence as "CUTTER" contains only 7% DEET the change in the Nylon elongation and modulus must come from the other solvents in the product. It is suggested that if a rope has significant amounts of Nylon to use insect repellents with 95-100% Deet instead of ones with some Deet and large amounts of other oil based solvents.

Best regards,

Carlos Williams
Honeywell Performance Fibers"


"Regarding dynema/spectra. In the most unscientific test ever run when I was working at Ragged Moutain Equipment in NH. We soaked several nylon and spectra slings in the strongest Deet concentraition we could find. Left ot on the hot metal roof of the store for several months and finally took it down and tested it. Most of the slings had been sun baked to white but all were at least 90% of what the normal breadking load would be. Do not try this at home kids with your own slings. In additon to that usefull information was supplied by Dupont and Allied fiber.

Joe"

There are quite a few natural insect repellents that are out there that don't contain DEET. Most contain citronell, lemongrass, etc...you can even look up a formula to make your own. I say either buy some/make a batch of your own and let your buddies use it. The natural ones work well, they just require more frequent applications. DEET is bad...not only to your gear, it's also pretty toxic crap.

I've used the natural ones in some crazy places, they worked for a very short period. DEET works great but now i have these strange twitches.
There is a product I used to use (Permethrin) that you could spray on your clothes and it would last several weeks. Don't know if it is still on the market. Now I live in Colorado. Not so worried now though.

Thanks all for your input. Allow me to summarize and put some closure to this discussion as I think there's some confusion out there.

All lab testing shows that DEET does nothing to affect the structural integrity of both nylon and Spectra/Dyneema. See evidence below. I'm convinced that climbing with DEET is ok for gear but as a general rule, it's still probably a good idea to generally keep your gear clean and protected from excessive amounts of UV, lotions, gels, liquids, powders, dirt, etc.


Nylon and DEET: http://edis.ifas.ufl.edu/IG122
Spectra/Dyneema and DEET: http://www.sterlingrope.com/2005/climbing_techtips.asp#chemr>>>>>

FYI - turns out Spectra and Dyneema are basically the same fiber, just manufactured by two different companies: http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_pol>>>>>

The one problem with DEET and climbing is the same as sunscreen and climbing. I never thin to apply it until just before I step up to the wall, and then I end up with greasy hands. As for the natural stuff, I use Badger for blackflies and no-seeums in the north east. It keeps them from buzzing so close. Apply to the brim of your hat. Doesn't keep the mosquitoes at bay so much though. Permethrin is still available, I've bought it, tried it on my clothes, decided I'd rather have malaria. (Its a pesticide). Works good around the edge of a mosquito net on a cot if you ever have to use such a thing though.

i guess this one goes in the category of stuff destroy-able by deet! i had a little bottle of Ben's 100 (i live in southern NH, and anyone who has been there in the summer knows why i have it!) stashed in a stuff sack. Accidentally got put into my haul bag and then crushed. Didn't realize until a couple hours later when the inside of my haul-bag had attained the consistency of gum. Its a black diamond one too, and the little blue bag was pretty much soaked with the stuff. i managed to save the main haul-bag by throughly scrubbing with soap and water and then scraping the effected material off with a knife. the blue bag and stuff sack were done for, as was a few rolls of tape. LUCKLY the deet missed all my ropes and gear in the haul bag, and with some duc-tape, the bag should be good as new (sorta)! i

if your gonna carry the heavy duty stuff, i'd recommend carrying it in some sort of crush proof container, and applying well away from any and all gear (and people!) and keep it away from all plastic based or technical fabrics like gore-tex.

News from the DEET-replacement front.

Consider a Therma-cell for belayer on single pitch. I might also suggest Yard Guard, but I guess that would be pretty bad for the environment. Once you're off the deck the problem is solved, skeeters don't fly that high. I have melted nylon tents with repellent--don't know if it was the DEET or another ingredient.