Diethyl chlorothiophosphate

Synonym(s):O,O′-Diethylthiophosphoric chloride;Diethyl phosphorochloridothionate

CAS NO.：2524-04-1
Empirical Formula: C4H10ClO2PS
Molecular Weight: 188.61
MDL number: MFCD00009088
EINECS: 219-755-4
SAFETY DATA SHEET (SDS)
Update Date: 2026-05-28 02:43:48

What is Diethyl chlorothiophosphate?

Chemical properties

CLEAR COLORLESS TO LIGHT YELLOW LIQUID

The Uses of Diethyl chlorothiophosphate

Diethyl Chlorothiophosphate is used in the preparation of various organophosporus insecticide including Flupyrazofos (F598620) and Chlorpyrifos (C425300).

General Description

A colorless to light amber liquid with a disagreeable odor. Density 1.196 g / cm3. Boiling point 120°F.Flash point below 100°F. Insoluble in water but soluble in most organic solvents. May be highly toxic and irritating to the eyes and lungs. Used as an intermediate for pesticides, as an oil and gasoline additive, and as a flame retardant.

Air & Water Reactions

Highly flammable. Insoluble in water but soluble in most organic solvents. Contact with moisture in the air produces highly corrosive and toxic fumes containing hydrogen chloride. Decomposes in water producing acidic products.

Reactivity Profile

Diethyl chlorothiophosphate is incompatible with bases (including amines), with strong oxidizing agents, and with alcohols. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291].

Health Hazard

TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

Flammability and Explosibility

Non flammable

Properties of Diethyl chlorothiophosphate

Melting point:	-75℃
Boiling point:	96 °C
Density	1.2 g/mL at 25 °C(lit.)
vapor pressure	1.4 mm Hg ( 50 °C)
refractive index	n20/D 1.472(lit.)
Flash point:	>230 °F
solubility	Chloroform (Slightly), Ethyl Acetate (Slightly)
form	liquid
color	Colorless to Red to Green
Water Solubility	hydrolyzes, immiscible
CAS DataBase Reference	2524-04-1(CAS DataBase Reference)
NIST Chemistry Reference	Phosphorochloridothioic acid, o,o'-diethyl ester(2524-04-1)
EPA Substance Registry System	O,O-Diethyl chlorothiophosphate (2524-04-1)

Safety information for Diethyl chlorothiophosphate

Signal word	Danger
Pictogram(s)	Corrosion Corrosives GHS05 Skull and Crossbones Acute Toxicity GHS06 Environment GHS09
GHS Hazard Statements	H302:Acute toxicity,oral H314:Skin corrosion/irritation H411:Hazardous to the aquatic environment, long-term hazard
Precautionary Statement Codes	P273:Avoid release to the environment. P280:Wear protective gloves/protective clothing/eye protection/face protection. P301+P312:IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell. P303+P361+P353:IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.