What harm is involved in using repellant with DEET?
DEET has a remarkable safety profile after 40 years of use and nearly 8 billion human applications. No correlation has been found between the concentration of DEET used and the risk of toxic effects. When applied with common sense, DEET-based repellents can be expected to provide a safe as well as a long-lasting repellent effect. – New England Journal of Medicine, July 4, 2002, authored by Mark S. Fradin, M.D. and John F.