But now, research reveals another possible cause — and it's found in many everyday products like household degreasers and dry-cleaned clothes.

This chemical, known as tetrachloroethylene (PCE), is used to remove grease from metal parts, fabrics, and household surfaces. PCE is now under intense scrutiny after new findings reveal that it can lead to liver damage, particularly liver fibrosis.

Researchers Link PCE to Hidden Liver Damage

A recent study published by researchers from Keck Medicine of USC analyzed PCE exposure affects the liver. The study, published in Liver International,1 examined data from the National Health and Nutrition Examination Survey (NHANES), a long-running health survey that tracks chemical exposure and disease trends in the United States.2

•Conducting the study — The researchers measured PCE exposure by analyzing blood samples from 1,614 adults aged 20 and older collected between 2017 and 2020 — the most recent data available. They found that about 7% of the population had measurable levels of PCE in their bloodstream, which is a clear sign of ongoing environmental exposure.

•Comparing PCE levels — The researchers next compared individuals with detectable PCE in their blood to those without it. What they found was striking — those exposed to this chemical were three times more likely to develop significant liver fibrosis. This implies that even people who don't drink alcohol or are obese could still develop liver scarring due to this invisible environmental toxin. In addition, these findings remained consistent regardless of age, sex, race, ethnicity, or education level.

•What is liver fibrosis? Simply put, fibrosis refers to scarring that disrupts the liver's ability to filter toxins and regulate metabolism. It's characterized by appetite loss, nausea, unexplained weight loss, and weakness. When fibrosis becomes severe and extensive, it leads to liver cirrhosis.3

•The higher the levels, the greater the risk — For every single nanogram per milliliter increase of PCE in the bloodstream — an amount so tiny it's measured in billionths of a gram — the risk of liver fibrosis increased fivefold. This indicates that even small, consistent exposures could have serious long-term effects, making it particularly concerning for those regularly exposed to the chemical.

•PCE exposure overrides typical liver disease risk factors — Notably, when this chemical was present, alcohol use and liver fat accumulation associated with obesity and other health conditions did not seem to contribute to significant liver fibrosis. According to Dr. Brian P. Lee, hepatologist and liver transplant specialist with Keck Medicine and the study's lead author:

"Patients will ask, how can I have liver disease if I don't drink and I don't have any of the health conditions typically associated with liver disease, and the answer may be PCE exposure. The findings suggest that exposure to PCE may be the reason why one person develops liver disease while someone with the exact same health and demographic profile does not."4

Facts About PCE — What It Is and How You Can Become Exposed

The researchers of the featured study noticed something unexpected about the population most at risk — They found that those who had greater PCE exposure came from higher-income households.5 This is because these people were more prone to getting their clothes dry-cleaned. In fact, dry cleaning is one of the main sources of exposure to this chemical.6

•PCE is colorless and used in various products — Also called perchloroethylene or ethylene tetrachloride, this clear, colorless, human-made liquid has been used not just as a dry-cleaning solvent, but also in household goods and other industrial settings. It has numerous uses, such as for removing grease, a heat transfer medium, and a drying agent for metals.

•Its odor is defined as sweet and similar to ether — However, relying on smell to detect exposure is misleading because the odor threshold (the level at which a person notices the smell) varies greatly and usually appears long after toxic exposure has already occurred. That means you could be breathing dangerous levels of PCE without even realizing it.

•Contaminated air and water are also sources of PCE — This chemical is released into the air over time, especially from freshly dry-cleaned clothes that continue to emit fumes even after cleaning. It also contaminates drinking water when spills or improper disposal allow the chemical to seep through soil layers and enter the groundwater supply.7

•PCE can easily enter the body — It can be inhaled, absorbed through the skin, or even enter through contaminated water or food. Once inside your body, it affects multiple organs, including the liver, kidneys, heart, and nervous system.

•Previous studies have linked this chemical to liver damage — While the featured study did shed light on how PCE can lead to liver fibrosis, there are earlier studies that have warned about its liver-damaging effects. According to an archived report from Agency for Toxic Substances and Disease Registry (ATSDR), PCE exposure has been associated with conditions such as hepatomegaly (an enlarged liver) and hepatocellular injury (damage to liver cells).8

Laboratory and occupational studies have also shown elevated levels of liver enzymes, indicating cellular stress and inflammation. Workers exposed to high levels of PCE in dry-cleaning facilities were found to develop these changes far more often than those who were not exposed.

PCE's Dangers Extend Beyond the Liver

Because of its toxic nature, the U.S. Environmental Protection Agency (EPA) has initiated a 10-year plan to phase out PCE use in dry cleaning and has either banned or tightly restricted its use in many workplaces. Still, the chemical continues to appear in certain products and remains widely used in countries that lack comparable safety regulations.9 This is particularly concerning, as PCE has been associated with a wide range of side effects. Although some are mild, others are severe and life-threatening.10

•Physical contact with the chemical is dangerous — When PCE comes into contact with your skin and eyes, it will lead to irritation and burning. The skin may develop rashes, blisters, redness, dryness, and cracking as well. When inhaled, it will irritate the nose, throat, and lungs.

•Prolonged exposure can lead to more serious effects — These include nerve damage, heart rhythm problems, and reproductive harm. Pulmonary edema, a dangerous buildup of fluid in the lungs, can also occur with chronic exposure. It causes difficulty breathing, making it a life-threatening condition.

•The central nervous system is one of the most sensitive targets of PCE toxicity — This means your brain and nerves respond to the chemical even before other organs show damage. People exposed to this chemical via air or water often develop symptoms like dizziness, blurred vision, confusion, and headaches.

These neurological symptoms occur because PCE acts like an anesthetic. It slows brain activity and interferes with neurotransmission (the process by which nerve cells communicate). What's most troubling is that these symptoms often fade once someone leaves the contaminated environment, making it easy to overlook or misdiagnose.

For anyone who works with solvents, noticing recurring "brain fog" or lightheadedness after a shift could be a warning sign that the body is overloaded with toxins.

•Kidney damage was another major finding highlighted in the ATSDR report — Studies have documented increases in urinary proteins such as beta-2 microglobulin and lysozymes among chronically exposed workers, which are early warning signs of tubular injury in the kidneys.

•The reproductive system also appears highly vulnerable — PCE exposure has been linked to menstrual irregularities, changes in semen quality, reduced fertility, and adverse pregnancy outcomes, including miscarriages, stillbirths, and low birth weight. Although the evidence varies across populations, researchers consistently found that PCE crosses the placenta and even appears in breast milk.

•PCE is carcinogenic — The International Agency for Research on Cancer has classified it as a probable human carcinogen;11 it's strongly linked to several cancers in both humans and animals, which is why it needs to be handled with extreme caution. According to the New Jersey Department of Health Hazardous Substance Fact Sheet:

"There is evidence that it causes cancer of the liver, esophagus, bladder, and other types of cancer in humans. It has also been shown to cause cancer of the liver and leukemia in animals.

There may be no safe level of exposure to a carcinogen, so all contact should be reduced to the lowest possible level."12

Limit Your Exposure to These Liver-Damaging Chemicals

The researchers highlight the importance of their findings, particularly for people who are at high risk of liver damage. "If more people with PCE exposure are screened for liver fibrosis, the disease can be caught earlier and patients may have a better chance of recovering their liver function," Lee said.13

•The easiest way to reduce the risk is to remove the main sources of PCE in your environment — For example, if you use dry cleaning services, switch to wet-cleaning or CO?-based methods that don't rely on solvents. When you need to dry-clean garments, hang them outside or in a well-ventilated space for at least 24 hours before wearing or storing them.

•Check your household chemicals as well — If you have household degreasers, adhesive removers, or stain removers that list "perchloroethylene," "tetrachloroethylene," or "PCE" on the label, get rid of them immediately. Every change you make — no matter how small — reduces the chemical load your liver has to process each day.

•Beware of other liver-damaging "forever chemicals," too — In particular, exposure to polyfluoroalkyl or perfluoroalkyl chemicals (PFAS), which include PFOA and PFOS, has been associated with fatty liver disease. When these endocrine-disrupting chemicals accumulate in the liver tissues, they can accelerate metabolic changes that lead to fatty liver. Read more about it in "Toxic To-Go Containers Linked to Liver Disease."

Your liver is one of the largest and most vital organs in the body. It performs more than 500 vital functions, such as detoxification, energy regulation, bile production, nutrient storage, immune function, and more. Many of these processes take place simultaneously.14

Everything you eat, drink, breathe, and absorb through your skin eventually passes through the liver for evaluation and processing. Without its continuous work, your body's internal balance, from metabolism to immunity, would unravel in a matter of days. Hence, it's only prudent to take extra steps to keep it well-functioning. In addition to avoiding PCE, below are additional strategies to keep your liver healthy and thriving.

•Eliminate linoleic acid (LA) and alcohol from your diet — Consuming processed and junk foods loaded with soybean, canola, corn, or anything labeled "vegetable oil," puts your liver under constant assault. Industrial seed oils are loaded with LA, which is metabolized into toxic byproducts called oxidized linoleic acid metabolites (OXLAMs). These are unstable, highly damaging molecules that disrupt cell membranes and set off chronic inflammation.

Meanwhile, alcohol is converted to acetaldehyde, a reactive aldehyde that interferes with your liver's ability to detoxify, regenerate, and store energy. If you already have belly fat, insulin resistance, or elevated liver enzymes, it's vital to cut out both seed oils and alcohol to give your liver a chance to heal.

•Prioritize choline-rich foods — Studies have shown that choline deficiency directly contributes to fatty liver disease and that restoring adequate levels helps reverse fat accumulation.15 The best food sources are pastured egg yolks (look for low-PUFA eggs) and grass fed beef liver.

•Maintain a healthy weight — Studies show that waist circumference is a stronger predictor of liver health than weight alone. Keeping your waistline in check and maintaining a healthy weight through a combination of a healthy diet and regular physical activity helps ease the pressure on your liver.16

•Be physically active — Incorporating movement in your life is linked to lower levels of liver enzymes, which are a key marker of liver damage and dysfunction. Taking short walks, even just 10 to 15 minutes after meals, helps lower blood sugar spikes, easing the metabolic load on your liver.

•Get adequate high-quality sleep — Maintain a consistent bedtime routine so you can get adequate, high-quality sleep at night. Getting enough rest at night allows your liver to repair and detoxify. It's also important to get early morning sunlight to reset your circadian rhythm. Check out my top sleep tips for more strategies to get a good night's sleep.

For a more comprehensive guide to maintaining a healthy liver, especially as you grow old, read "How to Keep Your Liver Healthy in Your 50s and Beyond." It provides lifestyle and dietary strategies, along with evidence-based supplementation, that will help your liver stay resilient as you age.

Frequently Asked Questions (FAQs) About Tetrachloroethylene (PCE) and Liver Damage

Q: What is tetrachloroethylene (PCE) and where is it found?

A: Tetrachloroethylene, also known as perchloroethylene (PCE) or ethylene tetrachloride, is a colorless chemical commonly used in dry cleaning, metal degreasing, and some household cleaning products. It's released into the air from freshly dry-cleaned clothes and can contaminate drinking water through spills or improper disposal that seep into soil and groundwater.

Q: How does PCE exposure affect your liver?

A: Exposure to PCE damages liver cells, leading to a condition called liver fibrosis, a buildup of scar tissue that disrupts the liver's ability to filter toxins and regulate metabolism. Studies show that even small increases in PCE levels in the blood raise the risk of liver fibrosis significantly, even in people who don't drink alcohol or have other common liver disease risk factors.

Q: What other health problems are linked to PCE exposure?

A: In addition to liver damage, PCE exposure affects the nervous system, kidneys, and reproductive organs. It's been associated with dizziness, headaches, confusion, nerve injury, heart rhythm problems, and reduced fertility. Long-term exposure is also linked to several cancers, including bladder, liver, and lymphatic cancers.

Q: How can you limit your exposure to PCE?

A: To reduce your risk, switch from traditional dry cleaning to wet-cleaning or CO?-based methods. Air out dry-cleaned clothing outdoors before wearing or storing it. Check household products like degreasers and stain removers — if they list "perchloroethylene" or "tetrachloroethylene," replace them with safer alternatives.

Q: What are the best ways to protect and support your liver naturally?

A: You can protect your liver by eliminating alcohol and seed oils from your diet, as both add extra toxic stress. Eat choline-rich foods like pastured egg yolks and grass fed beef liver, get daily sunlight to support cellular energy production, and stay active with short walks after meals. These habits help your liver repair, detoxify, and maintain long-term health.