What is DEET?
DEET (N, N-diethyl-m-toluamide) is the active chemical ingredient in most insect repellents available in the United States that are applied to the skin. DEET was developed more than 50 years ago by the U.S. Department of Agriculture for use by our military. It was registered for use by the general public in 1957.

How long has DEET been available to consumers and how widely is it used?
Americans have been using products containing DEET for more than 45 years. Approximately 30 percent of the U.S. population use DEET repellents each year. Use on children accounts for about 30 percent of all DEET insect repellent applications.

Does DEET require government approval?
All DEET-based products are carefully evaluated and registered by the U.S. Environmental Protection Agency before they are marketed in this country. For repellents, registrants must provide product performance data on each pest for which a claim of efficacy is made. For mosquitoes, regulatory agencies expect data on at least two different species of mosquito. As another example, for ticks that carry Lyme, a registrant is required to provide product performance data on the specific species of tick that is the known carrier, which is the Deer Tick.

Which DEET concentration should I use?
DEET insect repellents have a variety of concentrations based on a variety of uses. Generally, the longer you are outside, the higher concentration you should use. Higher concentrations are recommended for all outdoor activities in regions with large populations of biting insects or ticks. Other factors are the type of activity, temperature and geographic location. If you will be perspiring heavily due to vigorous activity, or the outdoor temperature is high, you may need a higher concentration. The EPA has determined that, when label instructions are followed, all concentrations can be used by individuals of all ages.

Should alternative repellents be used on children?
Two issues need to be considered when using repellents not containing DEET. First, as experts agree and tests have proven, the most effective repellents on the market contain DEET and those without it do not provide the same protection from insect bites. Using a non-DEET product could mean that children are at greater risk for bites, and that they may be bitten repeatedly before telling an adult or coming inside. Second, just because a repellent doesn't contain DEET does not mean it is harmless. In one scientific report, the authors wrote, "Unlike DEET, limited experience with natural oils used as insect repellents means their true safety profile has yet to be determined" (Goodyer & Behrens, American Journal of Tropical Medicine and Hygiene, 1998). The point is, DEET has a 45-year track record of reliable use and extensive scientific study, while much less is known about alternatives. [new]

Can I use a DEET insect repellent and sunscreen together?
The effectiveness of insect repellents and sunscreens are dramatically reduced when users apply them at the same time. Decide which is your top priority at the moment--protection from insects or from the sun--then apply either a repellent or sunscreen, plus use other measures to reduce insect and sun exposure. It is preferable to use a specially formulated product that combines both DEET-based insect repellent and sunscreen.

How long does bug season last?
Mosquitoes are most active from early spring until the first frost in many areas of the U.S. This is also true for ticks. In warmer regions, biting insects may be active year-round.