“DEET is a registered pesticide. DEET
is short for N,N-diethyl-m-toluamide (also known as
N,N-diethyl-3-methylbenzamide). It is a member of the toluene chemical family.
Toluene is an organic solvent used in rubber and plastic cements and paint
removers. DEET is absorbed through the skin and passes into the blood. The
Medical Sciences Bulletin, published by Pharmaceutical Information Associates
Ltd. reports, “Up to 56% of DEET applied topically penetrates intact human skin
and 17% is absorbed into the bloodstream.” Blood concentrations of about 3 mg
per litre have been reported several hours after DEET repellent was applied to
skin in the prescribed fashion. DEET is also absorbed by the gut.”
Scientists have discovered that not
only can DEET itself affect the central nervous system, but combined with
permethrin, which is another ingredient in mosquito repellents, it can lead to learning
and memory dysfunction and motor deficits. DEET may also be significantly more
toxic when combined with ethyl and isopropyl alcohols and Freon, which are also
in some DEET repellents. 