N,N-диэтил-m-толуамид

Описание

DEET was first developed and patented by the US Army in 1946. It was approved for general public use by the US Environmental Protection Agency (EPA) in 1957 and was reregistered in 1998. It has been estimated that more than 1.8 million kg (～4 million pounds) of DEET are used in the United States every year in more than 225 registered products. DEET is often sold and used in lotions or sprays with concentrations up to 100%. However, the Center for Disease Control recommends only 30–50% DEET to reduce the incidence of vector-borne disease transmission. Registered products must contain at least 95% of the meta-isomer, but small amounts of the more toxic ortho-isomer and the less toxic para-isomer are permitted.

Химические свойства

Colorless to Amberlike Liquid

История

Formulations registered for direct human application contain from 4% to 100% DEET. DEET was developed as a joint effort by the Department of Defense and U.S. Department of Agriculture (USDA). After examining hundreds of compounds for their repellent capabilities in the 1940s, DEET was selected and patented by the U.S. Army in 1946.the USDA did not announce DEET’s discovery until 1954, and it was registered for public use in 1957. DEET is prepared from m-toluoyl chloride and diethylamine in benzene or ether.

Определение

ChEBI: A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of m-toluic acid with the nitrogen of diethylamine. It is the most widely used insect repellent worldwide.

Показания

DEET is an organic liquid that is an excellent mosquito repellent; stronger preparations of DEET are also effective against stable flies, although little protection is provided against ticks. Commercial preparations are available in aerosol, cream, or lotion form and vary in concentration from 6% to 100%. Because DEET is absorbed into the bloodstream, it should be applied sparingly. Lesser concentrations of DEET should be used whenever possible, with additional applications to the skin if needed. Reports of a toxic encephalopathy and brief seizures have been documented in children after overzealous use. Less serious neurologic side effects include confusion, irritability, and insomnia. Contact dermatitis has been observed with preparations containing higher concentrations of DEET.
Use preparations with <20% DEET in children. Avoid mucous membranes, broken skin, and hands of children, because they are often in contact with the mouth. Spray clothing instead of skin whenever possible, but avoid contact with rayon, acetate, or spandex, because these materials may be damaged by DEET.

Общее описание

Clear colorless or faintly yellow slightly viscous liquid. Faint pleasant odor.

Реакции воздуха и воды

N,N-Diethyl-3-methylbenzamide is sensitive to prolonged exposure to moisture. Insoluble in water.

Профиль реактивности

N,N-Diethyl-3-methylbenzamide is incompatible with strong acids, strong bases and strong oxidizing agents. N,N-Diethyl-3-methylbenzamide hydrolyzes slowly in the presence of water. N,N-Diethyl-3-methylbenzamide has a solvent effect on most plastics, paints, and varnishes. N,N-Diethyl-3-methylbenzamide is also incompatible with rayon, acetate or dynel clothing.

Пожароопасность

N,N-Diethyl-3-methylbenzamide is combustible.

Профиль безопасности

Poison by intravenous route. Moderately toxic by ingestion and skin contact. Human systemic effects: coma, convulsions, dermatitis, mydriasis @upillary ddation), nausea or vomiting, stiffness. An eye and skin irritant. Experimental reproductive effects by skin contact. Mutation data reported. Can cause central nervous system disturbances. A pesticide. DEET is the active ingredient in most commercial insect repellents. When heated to decomposition it emits toxic fumes of NOx

Экологическая судьба

Historically, it was thought that DEET worked via blocking of insect olfactory receptors and that DEET masked the target to the insect senses so the insect would not detect a food source. Instead, however, recent evidence indicates that the odor of DEET is what acts as the true repellent. A specific type of an olfactory receptor neuron in the antennal sensilla of mosquitoes was identified, and this neuron is activated by DEET. This activity is responsible for the properties that give DEET its repellent ability.
DEET is also toxic to the central nervous system(CNS). DEET acts as an inhibitor to the enzyme acetylcholinesterase which is required for the proper functioning of the human nervous system, other vertebrates, and insects. The enzyme acetylcholinesterase hydrolyzes acetylcholine, which is important to muscle control. When this process is inhibited, acetylcholine builds up in the synaptic cleft and causes neuromuscular paralysis and death by asphyxiation.