DEET is a chemical (N,N-diethyl-meta-toluamide) used as the active ingredient in many insect repellent products. Approximately 230 products containing DEET are currently registered with the EPA as the substance can become toxic in certain dosages. It is now widely used, with approximately 30% of the U.S. population using DEET repellents each year. DEET products are currently available in a variety of forms: liquids, lotions, sprays, and even impregnated materials, such as wristbands. Formulations registered for direct application to human skin contain from 4% to 100% DEET.