Chlorpyrifos

Endpoint summary

Description of key information

The test substance is an off-white molten solid with a sweet odor. A melting point of 42°C was determined according to OECD Guideline 102 and EU Method A.1. The test substance decomposes between 170-180°C when tested according to OECD 103, EU Method A.2, and EPA OPPTS guideline 830.7220.  The relative density of 1.51at 20°C was determined in accordance with OECD Guideline 109 and EU Method A.3. The vapour pressure, 3.35 ×10-3Pa at 25°C, was determined using the Knudsen-Effusion Weight Loss Method in accordance with OECD Guideline 104 and EPA OPPTS guideline 830.7950. The mean log partition coefficient (log Pow) of 5.21 at 20°C was determined using the shake-flask method according to OECD Guideline 107, EU Method A.8, and EPA OPPTS guideline 830.7550. Water solubility of 1.05 mg/L at 20°C was determined according to OECD Guideline 105 and EPA OPPTS 830.7840.  Solubility in hexane was 77.4 g/100 ml of solvent and in methanol was 29.0 g/100 ml of solvent. In acetone, ethyl acetate, toluene and dichloromethane, the test substance was miscible in all proportions (>400 g/100 ml of solvent). The surface tension of a 90% saturated aqueous solution of the test substance was determined, according to OECD Method 115 and EU Method A.5, to be 72 mN/m at 20°C. The flash point of the test substance was not determinable according to EU Method A.9; no flash was observed below 360°C. The test substance was auto flammable at 285 °C in a test conducted according to EU Method A.15. The test substance was not explosive in a series of tests conducted according to EC Method A14 and is not oxidising based on results from a study conducted according to EU Method A.17. A 1% solution of the test substance has a pH of 4.04 at 22°C. A dissociation constant could not be determined according to OECD guideline 112.