buzz off makes insect repellent clothing by permeating fabric with permethrin, a pesticide that can endure 25 washings (the ‘product life’ according to their site). this pesticide is only a ‘possible’ human carcinogen according to the EPA, for whom this is the only approved repellent clothing today. now that repellents can be part of clothes, when will clothing become a drug delivery method in themselves? your lucky shirt may actually make you feel that way, with only minor side effects.