True Quality CleaningStraight talk about caring for fine garments & household textiles from an expert who calls it like it is. In plain English.

A brief guide to understanding drycleaning solvents and fluids

Drycleaning machinesVery briefly, there are 5 major components to a drycleaner's service: cleaning, finishing (aka pressing), inspecting, repairing and packaging.

The drycleaning solvent or fluid used in the cleaning process is probably the most critical part of the cleaning component.

There are primarily 6 drycleaning solvents or fluids in use today.


Perchloroethylene (aka perc or PCE), a chlorinated solvent, is the most common drycleaning solvent in use today. Used by approximately 90% of the 26,000 cleaners in the USA, perc (brand name: Dowper from Dow Chemical and PerSec from Occidental Chemical) is valued for its grease-cutting properties. (If I ran a uniform rental operation specializing in auto repair shops, I'd definitely want to clean in perc.)

In recent years, perc has been attacked by governmental agencies, scientific bodies and environmentalists as a potential human carcinogen as well as a ground water and air pollutant. Perc has been scheduled for phase out in California by the year 2023. By contrast, advocates for perc have argued that perc, used in accordance with existing environmental laws and regulations, is perfectly safe.

The debate over perc is on-going and contentious with a wealth of scientific and anecdotal evidence supporting both sides of the debate.

solvent drumsBut health and environmental safety is not my beef with perc. My concern is that perc is a relatively fabric aggressive, dye stripping solvent. Way too damaging for the bespoke, made-to-measure, designer, high fashion, specialty and couture garments in which I specialize.

Synthetic petroleum

About 7% of cleaners use synthetic petroleum, a hydrocarbon solvent that's a byproduct of the manufacture of gasoline (brand name: DF 2000 from Exxon Mobil Chemical or EcoSolv from Conoco Phillips Chemical). Synthetic petroleum is often falsely positioned as an organic, green, non-toxic and environmentally friendly alternative to perc.

While synthetic petroleum is relatively more gentle on your fine garments and household textiles than perc, it is, nonetheless, subject to the same federal, state and local environmental laws and regulations as perc, both in how it's used and how it's disposed of.

From a health and environmental point of view, all hydrocarbon solvents are volatile organic compounds (VOCs). VOCs contribute to the formation of ozone, which, in turn, has been linked to various respiratory complications.

Many cleaners that use synthetic petroleum like to refer to themselves as "organic cleaners". Technically, synthetic petroleum is "organic" because it contains carbon. But so is nuclear waste technically organic because it contains carbon. And so is perc, the "bad" cleaning solvent that synthetic petroleum was supposed to replace. To suggest that synthetic petroleum is organic in the same way that an apple is organic is deceptive and misleading. Actually, it's more than that. It's a scam.

In a previous post, I addressed the deceptive and misleading practice of referring to synthetic petroleum as "organic".


Fewer than 3% of all cleaners use siloxane (brand name: Green Earth from General Electric Silicones, Dow Corning Silicones and Shin Etsu Silicones).

Green Earth logoSiloxane is completely odorless and dermatologically friendly. You can even wash your face and hands in it.

It's extremely gentle. So gentle, in fact, that it's been used for decades as a base ingredient in many personal care products you drip into your eyes and rub into your skin on a daily basis. Such as shampoos, antiperspirants, deodorants and moisturizing creams.

It's also chemically inert. Which means that siloxane won't "bleed" or "fade" your colors.

HAZMATFrom an environmental point of view, siloxane is non-toxic. It's much more than just environmentally friendly. It's biodegradable. And it's environmentally benign. In the event of a major spill, siloxane degrades quickly in the environment into silica and trace amounts of water and carbon dioxide.

Contrast this to perc or synthetic petroleum. In the event of a major spill, a cleaner using siloxane will need a bucket and a mop. In the event of a major spill, a cleaner using perc or synthetic petroleum will need to summon your Fire Department's Hazardous Materials Unit.

From a health point of view, first aid measures for siloxane state that no action is required when siloxane comes into contact with skin or is inhaled or ingested. This differs markedly from first aid measures (wash, flush, consult a physician) for perc and synthetic petroleum solvents.

Pure liquid carbon dioxide

At room temperature and normal atmospheric conditions, carbon dioxide (CO2) is a colorless and odorless gas. When subjected to high pressure in a closed vessel such as a high pressure drycleaning machine, CO2  transforms into a liquid. This is the principle behind CO2  cleaning.

Although CO2  is a naturally occurring and generally benign substance, there are relatively few pure CO2  installations in North America (less than 50).

That's because the acquisition cost of a CO2  machine is relatively high (about 2 to 3 times the cost of a similarly sized perc or synthetic petroleum or siloxane machine); the cleaning performance is relatively poor (CO2 is a good rinse but removes next to no soil or stains); and the environmental impact is not as advertised (a CO2 machine releases 6 to 10 pounds of CO2  into the atmosphere at the end of each cleaning cycle).

From an environmental point, CO2 is a volatile organic compound (VOC) than can contribute to global warming.

Hybrid glycol ether/liquid carbon dioxide

Hybrid glycol ether/liquid carbon dioxide is the most recent addition to the industry's repertoire of drycleaning solvents and fluids.

Hybrid glycol ether/liquid carbon dioxide is a variation on the pure liquid CO2 drycleaning process and takes place in a machine manufactured by Solvair.

Instead of being cleaned in pure liquid CO2 your garments and household textiles are first cleaned in Dipropylene Glycol normal Butyl Ether (aka DPnB), what Solvair calls their "biodegradable cleaning liquid".

After being cleaned in glycol ether, your garments and household textiles are rinsed in pure liquid CO2 and dried when the liquid CO2 converts to a gas and the gas is extracted from the system.

According to the EPA, glycol ether is a suspected neuro-toxin, respiratory-toxin and kidney-toxin.


WaterfallsLet's not forget that water is the oldest "solvent" and is often used in combination with drycleaning to ensure that both oil-based and water-based stains and soils are removed from garments and household textiles.

Today, this water-based process is often called wetcleaning.

It is important to note, however, that wetcleaning is not "washing". Even the most technologically advanced home washing machines or professional shirt washers cannot match the capabilities of today's specialized, computer-controlled wetcleaning equipment. Micro-processors control water temperature, cylinder speeds, mechanical action and moisture removal.

What's this all mean for you?

Now that you know the specific solvents or fluids used in drycleaning today, it's important to find out three things from your cleaner:

  • What specific drycleaning solvent or fluid does your cleaner use?
  • What are the specific properties of that solvent or fluid?
  • What is the impact of the specific solvent or fluid on your fine garments and household textiles?

In answering these questions, forget about popular terms such as natural, sustainable, biodegradable, non-toxic, essentially non-toxic, practically non-toxic, EPA approved, non-regulated, non-ozone depleting , ozone friendly, ozone safe, VOC free, environmentally friendly, environmentally safe, environmentally preferable,  environmentally superior, earth friendly, earth safe, eco friendly, eco safe, green, organic, alternative, or any other similar name your cleaner can conjure up.

A ton of words that, in most cases, means absolutely, positively nothing.

It's important to recognize that many cleaners use these terms to intentionally confuse or obfuscate, not to educate or enlighten. That many cleaners are purposely ambiguous about the drycleaning solvent or fluid they use (they just don't want you to know). And that some clean in perc and claim to clean in synthetic petroleum, while others clean in perc or synthetic petroleum and claim to clean in siloxane.

To discover this for yourself view the website of any cleaner and try to identify the specific solvent or fluid used by that cleaner. I'd bet that 9 times out of 10 it's undisclosed. Now, ask yourself why?

Here's an even better way to identify the actual solvent or fluid used by a drycleaner. Every county has an air quality control department that regulates the use of perc or synthetic petroleum solvents by drycleaners in that county. Call them and ask for a copy of the dry cleaner's operating permit. The solvent or fluid they use will be right there -- in black and white. (In the metro Phoenix area, call the  Maricopa County Air Quality Department, (602) 506-6201).

Knowing the specific solvent or fluid used, its properties and it's impact is critical to cutting through the fog of confusing terms in the drycleaning marketplace.

How can I help you?

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