Sulfotep (also known as tetraethyldithiopyrophosphate and TEDP[8]) is a pesticide commonly used in greenhouses as a fumigant.

It has a cholinergic effect, involving depression of the cholinesterase activity of the peripheral and central nervous system of insects.

Sulfotep is a mobile oil that is pale yellow-colored and smells like garlic.

A Registration Standard for the chemical was issued by the Environmental Protection Agency in September 1988.

[13] An alternative route to TEPP can be a reaction of diethyl chlorothiophosphate an aqueous solution of sodium bicarbonate (Na2CO3).

[14] The chemical also reacts to form toxic and flammable gases in the presence of hydrides and other reducing agents.

It is miscible with a large number of organic solvents, including methyl chloride and acetone[18] and its solubility in water is 30 milligrams per liter at 20 °C (68 °F).

[15] The alkaline and neutral hydrolysis of sulfotep results in the release of ethanol, phosphoric acid, and hydrogen sulfide.

[10] Sulfotep is used in greenhouses as a fumigant formulation to control aphids, spider mites, whiteflies and thrips.

It is formulated as impregnated material in smoke generators containing 14 to 15% active ingredient.

Sulfotep kills spider mites, mealybugs, whiteflies, and aphids.

[22] However, it occasionally causes minor damage to plants, such as the slight puckering and cupping of leaves.

[23] During several tests in the late 1940s, it was found to be the most toxic of several chemicals to whiteflies on vegetables, two-spotted spider mites on roses, and mealybugs on numerous plants.

[22] A mixture containing 5% sulfotep at the concentration of 0.5 grams of phosphate per 1000 cubic feet was found in tests in the late 1940s to kill 100% of nonresistant two-spotted spider mites and 68-97% of resistant two-spotted spider mites.

[23] Sulfotep, just as all organophosphate pesticides, irreversibly inactivates acetylcholinesterase, which is essential to nerve function in insects, humans, and many other animals.

A few different organizations determined a maximum concentration sulfotep in the air.

The plasma cholinesterase activity decreased and the weight of the lungs of female rats increased.

Dogs who were orally exposed to 0, 0.5, 3, 5, 15 or 75 ppm (equivalent to 0–3.07 mg/kg/day) for 13 weeks, ate less and lost weight.

The plasma cholinesterase activity was already affected by a sulfotep concentration of 3 ppm (or higher).

[26] According to the Occupational Safety and Health Administration, the upper limit on exposure of sulfotep to human skin is 0.2 milligrams per cubic meter.

Within the first hour after a poisonous intake of sulfotep people often suffer from nausea or headaches.