o-Dichlorobenzene
C₆H₄Cl₂·Affects liver, kidneys
An industrial solvent and chemical intermediate (1,2-dichlorobenzene). Used in pesticide and dye manufacture and as a degreaser.
C₆H₄Cl₂
EPA limit
0.6 mg/L (MCL)
Most at risk
Households on private wells near chemical manufacturing or industrial sites
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
o-Dichlorobenzene (1,2-DCB) primarily targets the liver and kidneys. Chronic exposure in animal studies produces hepatic damage, kidney effects, and changes to blood cell counts. The EPA's MCL of 0.6 mg/L is set to keep human exposure well below these documented effect levels.
Acute high-level exposure causes eye and respiratory irritation, headache, and central nervous system depression. The chemical is structurally similar to its isomer 1,4-dichlorobenzene but is more commonly an industrial contaminant than a household one.
o-Dichlorobenzene is not classified as a human carcinogen. IARC places it in Group 3 (not classifiable), and the EPA has not assigned a cancer descriptor. The MCL is based on non-cancer chronic effects.
Where it comes from
How it gets into your water
o-Dichlorobenzene enters water primarily through industrial discharge. It is used as a high-boiling solvent in chemical synthesis, as a feedstock for dye and pesticide manufacture, in metal degreasing operations, and as a heat-transfer fluid in industrial processes. Facilities producing or using the chemical can release it through process water or accidental spills.
Older industrial sites where 1,2-DCB was used as a degreaser or in pesticide formulation often have legacy groundwater contamination. The compound can also leach from improperly disposed industrial waste in landfills.
Chemical manufacturing
Dye, pesticide, intermediate production
Metal degreasing
Industrial solvent operations
Contaminated wells
Near chemical plants or landfills
Heat-transfer fluids
Industrial process discharge
Find out for yourself
Is it in your water?
Public water utilities test for o-dichlorobenzene and report results in the annual Consumer Confidence Report. Most municipal supplies report non-detect or trace levels well below the 0.6 mg/L MCL.
Private well owners near chemical manufacturing facilities, dye producers, pesticide formulators, or industrial sites with historical solvent use should request a VOC panel that includes o-dichlorobenzene. The compound typically appears alongside its isomer 1,4-DCB and other chlorinated benzenes in contaminated plumes.
The fix
How AquaOx filters it
Activated carbon is the EPA's recommended best-available technology for filtering o-dichlorobenzene from drinking water. The Centaur catalytic carbon and coconut shell activated carbon stages in The AquaOx adsorb the compound efficiently, with independent testing showing high reductions across the chlorinated benzene family.
Whole-house filtration also reduces inhalation exposure from showers and baths, which matters for volatile compounds like 1,2-DCB.