IUPAC Name: 2,2-Dichloropropionic acid
MCL: 0.2 ppm
Source: Formerly used as an herbicide, also forms as a byproduct from disinfection processes.
Summary: Dalapon (2,2-dichloropropanoic acid) is used as an herbicide. It may also form as a byproduct of disinfection processes. It exists as a colorless liquid at room temperature. It has a solubility in water of 502,000 mg/L at 25 C and has a density of 1.4014 g/mL at 20 C. Upon decomposition it produces hydrogen chloride gas. It has an acid dissociation constant of 1.74. Dalapon exists in the vapor-phase in the atmosphere and has a half-life of 29 days undergoing reaction with hydroxyl radicals. Koc values range from 1-2, so the compound is highly mobile within soil. The average half-life within soils ranges from two to four weeks with varying rates of biodegradation dependent on soil type. Photolysis may be an important natural removal process in water. Dalapon is no longer produced in the United States.
GHS Hazard Statement: H313, H315, H316, H318, H320, H332, H412, GHS05, GHS07