With just one application, The 10 Hour Insect Repellent will protect you from biting insects including mosquitoes, ticks, fleas, no-see-ums, chiggers, horse flies and biting flies for up to 10 full hours. Product Description Repel insects that are known for carrying diseases such as West Nile Virus, Encephalitis, and Lyme Disease with a 100% DEET insect repellent that has been tested in the field. The 10 Hour Insect Repellent is designed for outdoor work crews who are in the elements with biting insects, such as mosquitoes, chiggers and ticks all day. The active ingredient is 100% DEET (N, N-Diethyl-m-toluamide) to offer up to 10 hours of protection without reapplication. Because you only need a few sprays, the 2 oz. atomizer spray typically lasts as long as 3 aerosol cans. There is no scent added to The 10 Hour Insect Repellent and it is formulated not to sweat off. The history of DEET In 1954, after 15 years of research and testing of over 11, 000 compounds, DEET insect repellent was developed by the United States Department of Agriculture for the U.S. Army. This formulation has been found to be the most effective insect repellent available to give them the protection needed. The 10 Hour Insect Repellent is now standard issue in the first aid kits of utilities, railroads, park crews and forestry departments.