Which dry cleaning solvent is safest? Wet cleaning and liquid CO2 systems currently carry the lowest documented health risk, followed by hydrocarbon solvents and GreenEarth’s silicone-based process. Perchloroethylene (PERC) has the strongest evidence of harm and is being phased out in several states.
That’s the short answer. Here’s the longer one, with the actual data behind it.
Why This Question Matters More Than It Used To
For decades, “dry cleaning” basically meant one chemical: perchloroethylene, or PERC. About 80% of conventional dry cleaners in the U.S. still use it as their primary solvent. It works fast, cuts through grease, and doesn’t shrink fabric — which is exactly why it stuck around so long.
But the health data on PERC has been piling up for years. The EPA has declared PERC a “likely human carcinogen,” and the International Agency for Research on Cancer classifies it as a Group 2A carcinogen — probably carcinogenic to humans. Those aren’t fringe assessments. They’re the two most-cited regulatory bodies in the world on this question. Environmental Working Group, American Council on Science and Health
PERC vs GreenEarth: PERC is more effective on tough grease stains, but GreenEarth’s silicone-based solvent breaks down into sand, water, and CO2 with far lower long-term toxicity data. GreenEarth works better for anyone repeatedly exposed — dry cleaning employees, or people who wear dry-cleaned clothes daily.
What the Research Actually Shows
According to the EPA, tetrachloroethylene exposure in dry cleaning workers has been linked to bladder cancer, kidney cancer, and non-Hodgkin lymphoma risk. A separate NYC-based study found that people living near PERC-using dry cleaners had elevated kidney cancer risk compared to those living farther away — the first study to make that specific connection.
Short version: it’s not just workers who breathe it in. Neighbors do too.
The Four Solvents, Explained Plainly
Most guides list these options without telling you which one actually matters for your situation. Here’s what each one is, in plain terms.
PERC (Perchloroethylene). The old standard. Chlorinated solvent, strong odor, effective on stains, now regulated out of existence in multiple states.
Hydrocarbon (EcoSolv, DF-2000). A petroleum-based solvent, gentler than PERC, no evidence of carcinogenicity at this point. It’s combustible, so cleaners need proper ventilation and fire safety — a limitation this article won’t pretend doesn’t exist.
GreenEarth (silicone-based, D5 siloxane). Marketed as part of the broader eco-friendly dry cleaning revolution. Breaks down into inert byproducts. Some older studies flagged D5 siloxane concerns in high-dose animal studies, though current consumer-level exposure data hasn’t shown the same carcinogenic profile as PERC.
Wet cleaning / liquid CO2. No petrochemical solvent at all. Wet cleaning uses water and biodegradable detergents in computer-controlled machines; CO2 systems use pressurized carbon dioxide instead of a chemical bath. Both currently sit at the bottom of the risk list.
Quick Comparison
| Solvent | Best For | Key Benefit | Limitation |
|---|---|---|---|
| PERC | Tough grease stains | Fast, effective, cheap | EPA-classified likely carcinogen |
| Hydrocarbon | Everyday garments | No carcinogen classification | Flammable; needs ventilation |
| GreenEarth | Delicate fabrics | Breaks down to inert byproducts | Higher cost, less common |
| Wet Cleaning / CO2 | Most fabric types | No chemical solvent used | Not ideal for heavy grease stains |
The California Rule Everyone’s Heard Of But Nobody Explains
Here’s the thing: a lot of readers have heard “California banned PERC” without knowing what that actually means for them.
In 2007, the California Air Resources Board adopted amendments that will phase out PERC dry cleaning machines by January 1, 2023, pushing the industry toward alternatives already on the market. The rule banned new PERC machine purchases starting January 2008, required machines 15 years or older to be phased out by July 2010, and mandated all remaining PERC machines be removed by January 1, 2023. The EPA approved the rule in 2011, making it the first statewide PERC ban in the country. CALexology
To follow that phase-out step by step:
- New PERC machine sales banned (2008).
- Machines near residences removed (2010).
- All remaining PERC machines shut down (2023).
Minnesota and New York have adopted similar restrictions, on different timelines. If you’re in one of those states, your local cleaner has likely already switched — whether they’ve told you or not.
Is Dry Cleaning Bad for You? The Honest Answer
Most people assume any dry cleaning is risky. The data says otherwise — it depends almost entirely on which solvent your specific cleaner uses, not on the process of dry cleaning itself. If you’re looking for a safe and professional service, utilizing a reliable dry cleaning service that uses modern, non-toxic methods eliminates the health concerns associated with traditional solvents.
If your cleaner uses PERC, the risk isn’t zero but it’s also not acute. Occasional exposure from picking up dry cleaning isn’t the same as daily occupational exposure. The bigger concern researchers flag is chronic, repeated exposure — for workers, and for people living or working next to a PERC facility.
I’ve seen conflicting framing on this across sources. Some outlets treat any PERC exposure as urgent and immediate; others (including EPA risk assessments) frame it as a long-term, dose-dependent concern. My read: for an occasional customer, airing out garments before wearing them meaningfully cuts exposure. For anyone with asthma, chemical sensitivity, or a PERC facility near their home, switching cleaners is the more protective move.
One caveat worth stating plainly: this article covers solvent chemistry and regulatory status. It does not cover dry cleaning’s environmental water/soil contamination legacy in detail, which is a separate (and serious) issue tied to older PERC disposal practices.
To Reduce Your Exposure Right Now
- Ask your cleaner which solvent they use.
- Air out garments outdoors for 24 hours before wearing.
- Choose hydrocarbon, GreenEarth, or wet cleaning where available.
The One Question to Ask Your Dry Cleaner
Skip the small talk. Ask this directly: “What solvent do you use — PERC, hydrocarbon, GreenEarth, or wet cleaning?”
If they hesitate or don’t know, that’s information too. A cleaner that’s invested in GreenEarth or CO2 equipment usually mentions it proudly — it’s a selling point, not a secret.
Common Questions
Q: What’s the best dry cleaning solvent for sensitive skin or allergies?
A: Wet cleaning tends to be gentlest, since it uses water-based detergents without chlorinated or petroleum solvents.
Q: How do I know if my dry cleaner uses PERC?
A: Ask directly, or look for a chemical, sweet odor on returned clothes — a common sign of PERC use.
Q: Should I stop using dry cleaners entirely?
A: Not necessarily. Switching to a hydrocarbon, GreenEarth, or wet-cleaning provider addresses most of the concern.
Q: Why does PERC smell so strong on clothes?
A: PERC is volatile and off-gasses slowly after cleaning, which is why freshly cleaned garments carry a noticeable chemical smell.
Q: When should I worry about PERC exposure?
A: Risk rises with frequency and proximity — dry cleaning workers and people living next to PERC facilities face more documented risk than occasional customers.
This guide covers solvent safety for typical consumers picking up dry cleaning. It isn’t medical advice, and it doesn’t replace guidance from a doctor if you have a diagnosed chemical sensitivity or respiratory condition — talk to a healthcare provider about your specific exposure risk.
