Deet, the popular and potent insect repellent, is neurotoxic

Some 200 million people a year use it, and apparently it's bad news for the brain and nervous system, particularly when combined with other repellents that have similar toxic effects.

From a Science Daily article:

The active ingredient in many insect repellents, deet, has been found to be toxic to the central nervous system. Researchers say that more investigations are urgently needed to confirm or dismiss any potential neurotoxicity to humans, especially when deet-based repellents are used in combination with other neurotoxic insecticides.

Vincent Corbel from the Institut de Recherche pour le Développement in Montpellier, and Bruno Lapied from the University of Angers, France, led a team of researchers who investigated the mode of action and toxicity of deet (N,N-Diethyl-3-methylbenzamide). Corbel said, "We've found that deet is not simply a behavior-modifying chemical but also inhibits the activity of a key central nervous system enzyme, acetycholinesterase, in both insects and mammals".

Popular Insect Repellent Deet Is Neurotoxic

Here is the original report: Deet inhibits cholinesterase: Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet