I would not believe the carcinogen claim that others mention. Also, even if
there is concern about minor claims, test animals are usually dosed to the
point where they are swimming in it and EPA and OSHA extrapolate data points
to zero where in real life curves do not go to zero, i.e. small quantites
have no effect.
I've hunted early deer seasons in marshy areas where bugs are unbelievable.
For me, clothes keep mosquitos away and I only spray around ankles to
prevent chigger bites and face and hands for ticks and mosquitos.