IUPAC Name: Dimethyl 2,3,5,6-tetrachlorobenzene-1,4-dicarboxylate
Source: Used as a pesticide on a wide range of crops.
Water Treatment: https://tdb.epa.gov/tdb/contaminant?id=10120
Summary: Dacthal is a colorless solid at room temperature. It has a low solubility in water at 0.5 mg/L at 25 C. It is used as a pesticide to control weeds and wild grasses before they emerge. It has a half-life of 36 days as a vapor in the atmosphere. It has a Koc value of 5900, meaning it is likely immobile within soil. Biodegradation in the subsurface produces monomethyl tetrachloroterephthalate and tetrachloroterephthalic acid. The Koc value indicates adsorption to suspended solids in water, and organic matter and clay in soil.