Parathion

CAS RN:56-38-2

Other Properties

Technical product is a brown liquid with a garlic-like odor. /technical product/
Can penetrate leather, canvas shoes, and sneakers.
Parathion will attack some forms of plastics, rubber, and coatings.
It is slowly hydrolyzed in water to form p-nitrophenol and diethyl orthothiophosphoric acid. The time for 50% hydrolysis is 120 days, but this occurs more rapidly in alkaline solution.
Incompatible with alkaline materials. Hydrolyzed very slowly in acidic media (pH 1-6), more rapidly in alkaline media; half-life 272 days at pH 4, 260 days at pH 7, and 130 days at pH 9 (all at 22 deg C). Isomerizes on heating above 130 deg C, to the O,S-diethyl isomer.
Henry's Law constant = 0.0302 Pa/cu m mole
Slow decomposition in air.
Parathion is reduced readily to the nontoxic O,O-diethyl O-4-aminophenyl phosphorthioate and oxidized with difficulty to the very highly toxic paraoxon O,O-diethyl O-4-nitrophenyl phosphorothiolate.
Find more information on this substance at: Hazardous Substances Data Bank , TOXNET , PubMed