1,1,2-Trichloroethane
1,1,2-TCA·Affects liver, kidneys
A chemical intermediate used to make vinylidene chloride and other industrial compounds. Classified by the EPA as a probable human carcinogen and regulated at 5 ppb in drinking water.
1,1,2-TCA
EPA limit
0.005 mg/L (MCL)
Most at risk
Households near chemical manufacturing plants, old industrial sites, or known contamination plumes
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
1,1,2-TCA targets the liver and the kidneys. Animal studies show clear hepatic and renal damage from chronic exposure. The EPA classifies it as a Group C probable human carcinogen based on evidence of liver tumors in mice.
Acute high-dose exposure can cause central nervous system depression, but the more relevant concern in drinking water is chronic low-dose exposure over years. Like other chlorinated solvents, it is volatile and contributes to inhalation exposure during showering.
The EPA MCL of 5 ppb is the same strict limit applied to TCE and PCE because of the carcinogenicity concern.
Where it comes from
How it gets into your water
1,1,2-TCA is used almost entirely as an industrial intermediate, primarily to manufacture vinylidene chloride, which goes into food wrap and other plastics. It has limited use as a solvent compared with its isomer 1,1,1-TCA.
Groundwater contamination comes from chemical plant releases, improper waste disposal, and leaks from solvent storage. The compound is dense and migrates downward through soil into aquifers, where it persists for years. Detections cluster around historic chemical manufacturing corridors.
Chemical plants
Vinylidene chloride manufacturing
Industrial waste sites
Improper disposal of process residues
Contaminated wells
Groundwater plumes near manufacturing areas
Underground tanks
Leaks from solvent storage
Find out for yourself
Is it in your water?
1,1,2-TCA is on the EPA's regulated contaminant list, so utilities must test for it and report detections on the Consumer Confidence Report. Detections in finished city water are uncommon.
Private well owners near chemical manufacturing areas or known Superfund sites should request a full VOC panel including 1,1,2-TCA. Because the MCL is low and the compound is a probable carcinogen, even trace detections warrant treatment.
The fix
How AquaOx filters it
Activated carbon is the standard treatment for chlorinated solvents. The Centaur catalytic carbon and coconut shell carbon stages in The AquaOx adsorb 1,1,2-TCA as water passes through.
For homes on a known industrial plume, we recommend pairing The AquaOx with the under-sink RO at the kitchen tap so drinking and cooking water gets a second-stage polish.