Is 100%DEET the only mosquito repellent that is effective? Can the repellent still work if it has only 20% DEET ?

Lower concentrations of DEET are still effective, but you may need to apply them more frequently. Perspiration will wash them off in time. For me, SOP is to apply to clothing first and then to skin when really needed.

Weve been using this,Mrs just said today she will pick up one for each vehicle.Works well IMO,deet free though Im not up on why that matters really? I do like the container,has a little flap thing that keeps top from depressing.Also spf 30,guess thats a good thing,why not.

As Doug mentioned, lower concentrations are fine. I use bug spray that only has 7% DEET and it works fine for me and is only re-applied as needed usually 2-3 x per day depending on the activity and the local mosquito population.

I like 100% DEET only in the tiny containers I carry in my kit, because in an emergency, I want enough to go around in a small package.

Excessive DEET on my skin sometimes makes me feel ill and dissolves the finish on my gun and burns into the lenses of my glasses.

When I use a standard spray can for everyday outdoor hiking/fishing etc, I use 40% DEET on my hat and shirt. If I have long pants on, I spray some on my pant cuffs and socks to ward off ticks.

I haven't used DEET since I was a kid for the same reason. I felt really bad after I applied it the first time and that put me off it for life. The fact that it dissolves so many man-made materials doesn't help either.