[pct-l] Deet 20% or 100%

[themtgoat at yahoo.com (The Mountain Goat)]

It may be true that deet works good with 20% and that below that 
the bloody thirsty varments may start to attack. But the 20-30%
in some trail tests in the late 1990's with my hiking companions
as unsuspecting test canidates, found that it was good for no more than
30 minutes, the 100% seemed to work for about 1 hour. sometime a litte
longer.

Good Luck to the Class of 06. I wish I could join you.
-Mountain Goat-


 

[pct-l] Deet     Jerry Goller      jerrygoller at backpackgeartest.org        
     Wed Feb  8 13:55:02 CST 2006          
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Interesting. According to the military's own research, concentrations of
DEET above 30% did not increase effectiveness. What did increase it was
timed release. The military developed a polymer based controlled released
formula that successfully addressed the break down issue and is available
commercially as 3M Ultrathon (just over 30% concentration) in both a cream
and a spray. Sawyer Controlled Release is a similar product with a
concentration of about 20%. 

The reason that 100% appears to work better is that DEET starts to break
down as soon as it is applied to the skin. It continues to break down until
it completely loses it's ability to repel, which is below 20%. Obviously, it
takes 100% longer to break down than it does 30%.

With controlled release DEET the DEET is encapsulated in a polymer at
"protects" the DEET molecules from breaking down. The polymers are
formulated to break down at different rates therefore allowing a constant
concentration of between 20 and 30%, depending on the brand, over a much
longer time period. Protection over 12 hours or greater is very common. I
only apply it once a day. 

Now I will agree that in very high concentrations of particularly aggressive
mosquitoes it is possible that augmentation with 100% concentration could be
beneficial. I've not run into that yet, but have read about it.

This system last longer than 100% DEET, is resistant to dilution by
sweating, is much more comfortable to wear, and it also tends to limit
dermal absorption of the DEET. 

We tested both products on BGT.

			
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