Dry-cleaning chemical linked to triple the risk of liver scarring

Overview

Updated Sep 8

The solvent that removes grease and stains from dry-cleaned clothes is in the blood of 7% of Americans. A new study finds these people are three times more likely to have significant liver fibrosis - the scarring that precedes cirrhosis and liver cancer.

Researchers at Keck Medicine of USC analyzed blood samples from 1,614 adults in the National Health and Nutrition Examination Survey (NHANES). When PCE breaks down in the liver, its metabolites react with liver cells, triggering inflammation and scar tissue. Each additional nanogram of PCE per milliliter of blood raised the odds of significant fibrosis fivefold.

The finding held after adjusting for alcohol use, metabolic syndrome, and other liver risk factors, pointing to PCE as an independent threat. The Environmental Protection Agency has begun a 10-year phaseout of PCE in dry cleaning, but the chemical remains in spot removers, adhesives, and stainless steel polish - and it lingers in groundwater from past spills.

Why it matters

A chemical in 7% of Americans' blood triples their risk of liver scarring - and the EPA is only now phasing it out.

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Key Indicators

US adults with detectable PCE in blood

From NHANES data collected 2017-2020, roughly 1 in 14 Americans carries the chemical.

3.2x

Odds of significant liver fibrosis with PCE exposure

Adjusted for age, sex, race, education, alcohol use, and metabolic syndrome (95% CI 1.2-8.2).

5.1x

Odds increase per 1 ng/mL of blood PCE

Dose-response relationship: higher PCE concentrations meant higher fibrosis risk (95% CI 1.1-24.3).

1,614

Adults included in the study analysis

NHANES participants aged 20 and older; people with hepatitis and smokers were excluded.

10 years

EPA phaseout timeline for PCE in dry cleaning

The agency also banned or placed workplace controls on other PCE uses.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Brian Lee

Lead researcher and hepatologist

Leading the PCE-liver fibrosis research at Keck Medicine of USC

Organizations Involved

Keck Medicine of USC

Academic Medical Center

Conducted the study

The research institution behind the PCE-liver fibrosis study, based in Los Angeles.

U.S. Environmental Protection Agency (EPA)

Federal Agency

Phasing out PCE in dry cleaning over 10 years

The federal agency regulating tetrachloroethylene use in the United States.

Centers for Disease Control and Prevention (CDC)

Federal public health agency

Runs the NHANES survey used in the study

The CDC's National Center for Health Statistics conducts NHANES, the survey that provided blood samples for the PCE analysis.

Timeline

January 2017 September 2026

3 events Latest: September 7th, 2026 · 2 months ago

September 2026
Keck Medicine alert republished on ScienceDaily
Latest Statement

The university's press release on the PCE-liver fibrosis link is redistributed, renewing public attention on the finding.
September 7th, 2026
October 2025
Liver International publishes the PCE-liver fibrosis study
Publication

Keck Medicine researchers report a 3.2x odds of significant liver fibrosis among adults with detectable PCE in blood.
October 27th, 2025
January 2017
NHANES begins collecting PCE blood measurements
Data Collection

The CDC's national health survey starts measuring tetrachloroethylene in participants' blood, a cycle that runs through 2020.
January 1st, 2017

Scenarios

EPA completes PCE dry-cleaning phaseout on schedule

Likely Resolves by End of 2035

Discussed by: Environmental health researchers at Keck Medicine, EPA policy analysts, dry-cleaning industry observers

The EPA's already-announced 10-year phaseout of PCE in dry cleaning proceeds through rulemaking. Dry cleaners transition to alternatives like wet cleaning, hydrocarbon solvents, or CO2-based systems. The new liver fibrosis data adds public health urgency and could accelerate the timetable or expand the ban to consumer products containing PCE.

Liver disease screening guidelines add PCE as a risk factor

Possible Resolves by End of 2030

Discussed by: American Association for the Study of Liver Diseases (AASLD) guideline committees, Dr. Brian P. Lee

If follow-up studies confirm the association, professional hepatology societies could add PCE exposure to the list of risk factors assessed during routine liver fibrosis screening. This would change how doctors evaluate patients with unexplained liver enzyme elevations or metabolic risk - adding an environmental exposure question to standard intake.

Prospective studies fail to confirm the PCE-liver link

Unlikely Resolves by End of 2032

Discussed by: Epidemiologists, researchers critiquing cross-sectional NHANES designs

The study's cross-sectional design cannot establish causality - it measures PCE and fibrosis at the same time. If prospective cohorts or mechanistic animal studies fail to reproduce the association, the regulatory case weakens and the finding fades from policy discussions, similar to how some early NHANES environmental findings did not survive replication.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1940s-1950s

Carbon tetrachloride in dry cleaning (1940s-1950s)

Carbon tetrachloride was the original dry-cleaning solvent, used widely from the 1930s. By the 1940s, it was recognized as a potent hepatotoxin causing liver necrosis in workers and consumers who used it in home spot removers.

Then

The industry replaced carbon tetrachloride with PCE, which was marketed as a safer alternative.

Now

Carbon tetrachloride became one of the most tightly restricted chemicals, with production eventually banned under the Montreal Protocol.

Why this matters now

This is the exact pattern repeating: one chlorinated solvent was swapped for PCE because of liver toxicity, and PCE is now under the same scrutiny.

January 1974

Vinyl chloride and liver angiosarcoma (1974)

Three workers at B.F. Goodrich's Louisville PVC plant died of angiosarcoma of the liver, an extremely rare cancer. Within months, vinyl chloride was identified as the cause through epidemiological investigation.

Then

The Occupational Safety and Health Administration issued an emergency temporary standard capping worker exposure.

Now

The discovery reshaped chemical safety regulation, establishing the precedent that industrial chemicals can cause liver disease even at previously 'acceptable' exposure levels.

Why this matters now

A direct precedent: liver disease traced to an industrial chemical, leading to federal action. The PCE finding is an earlier stage - fibrosis precedes cancer.

1953-1987

Camp Lejeune water contamination (1953-1987)

PCE and other volatile organic compounds contaminated drinking water wells at Marine Corps Base Camp Lejeune in North Carolina for three decades. Military families drank, bathed, and cooked with the water.

Then

The contamination was discovered in the 1980s and the wells were closed.

Now

The 2022 PACT Act provided disability compensation for affected veterans and families; studies found links to cancers and liver disease.

Why this matters now

Real-world evidence that PCE in drinking water has harmed thousands of Americans, showing the chemical's effects extend well beyond dry-cleaning workers.