Tetrachloroethene
PCE·Affects liver, kidneys, brain
The classic dry cleaning solvent, also called perchloroethylene or perc. One of the most common groundwater contaminants in the United States and a probable human carcinogen.
PCE
EPA limit
0.005 mg/L (MCL)
Most at risk
Households near current or former dry cleaners, metal finishing shops, or known industrial plumes
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
PCE targets the liver, the kidneys, and the central nervous system. Acute high-dose exposure causes dizziness, headache, and impaired coordination. Chronic exposure has been linked to liver and kidney damage along with neurobehavioral effects in workers and residents of contaminated communities.
The EPA classifies PCE as likely to be carcinogenic to humans. IARC lists it as Group 2A, probably carcinogenic, based on evidence of bladder cancer and non-Hodgkin lymphoma in dry cleaning workers and animal liver tumors. The MCL of 5 ppb reflects this cancer risk.
PCE is highly volatile, so showering, dishwashing, and even toilet flushing release the compound into indoor air. Inhalation exposure during these activities often equals or exceeds ingestion exposure from drinking the same water.
Where it comes from
How it gets into your water
PCE is the most widely used dry cleaning solvent in the world, accounting for the majority of dry cleaning operations through the late 20th century. Even careful operations released the compound through spills, vapor losses, and improper waste disposal. The dense, persistent solvent migrates downward through soil and forms long-lived groundwater plumes.
Beyond dry cleaning, PCE is used for metal degreasing in machine shops and electronics manufacturing. Vapor intrusion is also a major concern: PCE vapors migrate from contaminated groundwater into building basements, contaminating indoor air independent of the water supply.
PCE is one of the two most common groundwater contaminants in the United States (alongside TCE), and tens of thousands of Superfund sites and state cleanup sites involve PCE plumes.
Dry cleaners
Primary global source of PCE contamination
Metal finishing
Degreasing in machine shops and electronics
Contaminated wells
Widespread groundwater plumes
Industrial waste sites
Legacy disposal of cleaning solvents
Find out for yourself
Is it in your water?
PCE is EPA-regulated and all community water systems must test for it. Look at your Consumer Confidence Report for the latest detections. Because PCE is so widespread, many municipal utilities have detectable levels and use granular activated carbon plants to keep finished water below the MCL.
Private well owners in urban or suburban areas near current or former dry cleaners, machine shops, or industrial corridors should request a full VOC panel that includes PCE, TCE, the DCE family, and vinyl chloride together. EPA EnviroFacts and state cleanup site maps can help identify nearby sources.
The fix
How AquaOx filters it
Activated carbon is the proven treatment for PCE at both the municipal and home scale. The Centaur catalytic carbon and coconut shell carbon stages in The AquaOx adsorb PCE efficiently as water passes through, with independent testing showing reductions of more than 95% across the VOC family.
Whole-home filtration matters here in a way it does not for most contaminants: because PCE vaporizes during showers and dishwashing, treating only the kitchen tap leaves the household exposed through inhalation. For homes on a known plume, we recommend pairing The AquaOx whole-home system with the under-sink RO at the kitchen tap for a second-stage polish.