CAS number 78-34-2
PubChem 6531
ChemSpider 6283 YesY
Jmol-3D images Image 1
Molecular formula C12H26O6P2S4
Molar mass 456.2 g/mol
Appearance Thick reddish-brown liquid/powder, garlic odor
Melting point

−20 ºC

Solubility in water Insoluble
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Dioxathion, systematically known as p-dioxane-2,3-diyl ethyl phosphorodithioate, is an organophosphate pesticide. It is used as an insecticide on livestock and as an acaricide on citrus fruits, deciduous fruits and nuts.


Under the trade name Delnav, it can be used to control insects and mites on apples, pears, quince, grapes, and walnuts, and finds use in the control of ticks, horn flies, lice and sheep keds in various livestock, either as a spray or as a dip. Under the trade name Deltic, it is a restricted use pesticide for exterior control of fleas, ticks and mites, in kennels, dog houses, yards, and other recreational areas.


Dioxathion is an Extremely Hazardous Substance, as defined by Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act, and is no longer allowed to be sold in the United States. However, it continues to see use in some other countries. It has been known to cause inhibition of the enzyme cholinesterase in rats, and it is recommended that people who have exposure to dioxathion regularly get their plasma and red blood cell cholinesterase levels assessed. Persons exposed to other chemicals which affect cholinesterase levels, e.g. other organophosphates or carbamates, may be at an increased risk. There are no known carcinogenic or reproductive effects, but long term exposure may result in nerve damage, poor motor coordination, and personality changes of anxiety, depression or irritability.

Short-term effects may include irritation to the eyes, pupil constriction and blurring of vision, abdominal cramps, laboured breathing, nausea, vomiting, diarrhoea, muscle cramps and excess salivation. These are mostly classic symptoms of organophosphate poisoning.

Dioxathion must be stored away from alkalis, iron, tin and strong acids. Contact can be avoided by using protective clothing and eyeware. If poisoning occurs, a physician may administer atropine sulfate, or pralidoxime in case of severe poisoning.