Common Name

Chlorpyrifos

Action

Insecticide

Class

Organophosphate

CAS number

2921-88-2

Structural Formula

Physical and Chemical Characteristics

M.f. : C₉H₁₁Cl₃NO₃PS

Mol. Wt. : 350.6

Form : Colourless crystals, with a mild mercaptan odour

Chemical name :
 O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate

M.p. : 42-43.5 °C

V.p. : 2.7 mPa (25 °C)

Kow logP : 4.7

Henry :  6.76 × 10^-1 Pa m³ mol^-1 (calc.)

S.g./density: 1.44 (20 °C)

Solubility:
In water c. 1.4 mg/l (25 °C). In benzene 7900, acetone 6500, chloroform 6300, carbon disulfide 5900, diethyl ether 5100, xylene 5000, iso-octanol 790, methanol 450 (all in g/kg, 25 °C).

Stability:
Rate of hydrolysis increases with pH, and in the presence of copper and possibly of other metals that can form chelates; DT₅₀ 1.5 d (water, pH 8, 25 °C) to 100 d (phosphate buffer, pH 7, 15 °C).

pKa : N/A

Specification

Chlorpyrifos content, % ≥ 95.0
Water content, % ≤ 0.2
Acetone insoluble, % ≤ 0.5
Acidity, % ≤ 0.2