Description, Properties, and Major Uses
Chemical Technical Summary for Public Health
and Public Safety Professionals
Agency for Toxic Substances and Disease Registry
December 6, 2004
The physical and chemical properties of DEET are summarized in Table 1.
N,N-Diethyl-meta-toluamide, (DEET) (CAS# 134-62-3) is a nearly colorless liquid at room temperature with a faint, characteristic odor. Technical grade formulations contain 100% DEET (which contains a minimum of 95% of the meta isomer), and manufactured products contain anywhere from 4% to 100% (EPA 1999). Its chemical formula is C12H17NO, and its molecular weight is 191.272 (EPA 1999). DEET floats in water (specific gravity 0.996 at 20°C), and is practically insoluble. DEET has a vapor pressure of 5.6 x 10-3 mmHg at room temperature, so it will exist mostly in the vapor phase in the ambient atmosphere. The liquid boils at 160°C (HSDB 2001). DEET is very soluble in the solvents benzene, ethyl ether, and ethanol (HSDB 2001).
DEET is an insect repellent used by nearly 30% of the U.S. population annually, with 19% of U.S. households applying it multiple times on family members (EPA 1999). DEET is effective against a broad spectrum of insects including biting flies, chiggers, fleas, ticks, and mosquitoes (Fradin 1998). DEET is applied in the liquid form as a pressurized liquid spray (both pump and aerosol), by ready-to-use formulations in sticks and creams, and by donning impregnated material (EPA 1999; Brown and Hebert 1997). Although it has been added to lotions, creams, and sticks, the most common topical formulation of DEET is with the solvent ethanol (Proniuk et al. 2002). As of 1998, there were 225 registered DEET products ranging from 4% to 100% active ingredient concentration (EPA 1999). All products presently sold in the U.S. contain 4-40% DEET or 95% DEET.