By Laurel Vukovic
From Natural Health
July/August, 1994

Making human flesh unappetizing to mosquitoes, ticks, flies, and fleas is an age-old preoccupation.  The earliest insect repellents included smoke, mud, and various plant substances.  Our contemporary contribution is DEET (N, N-diethyl-meta-toluamide), a powerful insecticide found in over 400 repellents.  DEET can peel paint, damage rayon and spandex, and melt plastic.  Up to 56 percent of DEET applied to the skin enters the bloodstream, and reactions to it include skin rashes, lethargy, muscle spasms, nausea, and irritability.  An extreme reaction can cause seizures and even death.  So it's hardly worth using DEET to deter insects unless you're someplace with high rates of insect-borne disease or you experience severe allergic reactions to bites and stings.