1,3-Dichlorobenzene (m-Dichlorobenzene)

1,3-Dichlorobenzene is produced by selective chlorination of benzene but in smaller quantities than the ortho and para isomers [1]. It is used as an industrial solvent, in the synthesis of other chlorinated aromatics, and as a component of mixed dichlorobenzene solvent blends [2]. Environmental contamination occurs at sites where mixed dichlorobenzene solvents were used or disposed of — it is found in soil and groundwater at various industrial Superfund sites [1]. Like other chlorinated aromatics, it is mobile in groundwater and resistant to natural biodegradation [2].

Contaminated groundwater near former industrial solvent sites [1]. Occupational use of mixed dichlorobenzene solvents [2]. Some moth ball formulations historically contained mixed isomers [1].

1,3-DCB is metabolized to 3,4-dichlorophenol and related catechol/quinone intermediates that cause oxidative stress [1]. Liver and kidney toxicity occur at occupational doses. EPA Group D (not classifiable as carcinogenic) based on current evidence [2]. CNS depression at high concentrations [1].

Private well users near contaminated industrial sites [1]. Occupational solvent workers [2].

1. Test well water near industrial contamination sites [1]. 2. Activated carbon filtration [2].