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Green Dry Cleaning?

Over the past few years, I've seen many local dry cleaners claim to be eco-friendly.  I rarely have to use dry cleaners, but I've gotten curious over whether or not such a thing exists.

As of 2007, 85% of all dry cleaners in the US used perchloroethylene (perc) as a solvent when dry cleaning. Perc is a synthetic, volatile organic compound (VOC) that is both a health risk to humans and it's dangers to the environment. Even minor exposure to it can cause dizziness, headaches, drowsiness, nausea, skin and respiratory irritation. What's worse is that prolonged exposure has been linked to liver damage, kidney damage, and cancer. Perchloroethylene was identified as a "probable" human carcinogen by California’s Proposition 65 in 1986.

Even dry cleaning methods that claim to be green, are often not.  Ask them what their methods are before dropping your clothes off.  Some use hydrocarbon, which is petroleum based. Some use liquid CO2, but that will sometimes require a Solvair machine.  The Carbon Dioxide Dry Cleaner Alliance does not allow dry cleaners using Solvair to become members.  Solvair replaces perc with glycol ether as a solvent, and according to the EPA, glycol is a suspected toxin and hormone disrupter.  

GreenEarth is a common "eco-friendly" dry cleaning method.  I've found conflicting information on them.  Many articles say that they're a great alternative to traditional dry cleaning methods, but Wikipedia has a very well-sourced section on a bioassay revealing negative consequences in female rats when exposed to fumes for a long time.   

One fool proof way?  Wash your own clothes.  Most clothes that say they're "dry clean only" can indeed be washed with water.  Care2 has instructions.  


Solvair Information

Krissy, thank you for providing the forum for this discussion on green clothing care. I hope your readers will be patient with my long answer to Suzie Blodgett’s post:

Suzie, you are correct that DPnB (Dipropylene Glycol n-Butyl Ether) is a member of the propylene glycol ether family, as I communicated in my post above. One of the points I wish to clarify is that DPnB is not an ethylene glycol and that the term “glycol ether” is a generic term that can cover a wide variety of chemicals with extremely different properties.  Understandably, there are concerns about certain glycol ethers, particularly the ethylene family. Some of our competitors have tried to mislead consumers into thinking that Solvair uses an ethylene glycol, which is not the case. As you pointed out, when you read the MSDS sheets, DPnB does not share the hazards associated with those types of glycol ethers.  

DPnB was deliberately chosen for Solvair. Its performance benefits combined with the data from existing published and ongoing toxicological and environmental research on DPnB, and its history of safe usage in other products have shown it to be an ideal and appropriate ingredient for use in the system. For example, according to the Screening Information Data Set (SIDS) report by the United Nations Environment Program (UNEP), sponsored by the U.S. through the U.S. Environmental Protection Agency and The American Chemistry Council, concerning DPnB and related glycols:

  • It is a “low priority for further work.” (this may be one reason why there is less data and fewer studies compared to some other chemicals)  -UNEP UNEP OECD SIDS Report 2003 p6 
  • “In repeated dose studies few adverse effects were found even at high levels and effects that did occur were mild in nature.”  -UNEP UNEP OECD SIDS Report 2003 p5
  • “Mutagenicity: In vitro and animal genetic toxicity studies were negative.”
  • In animal studies, “did not interfere with reproduction.”  -UNEP UNEP OECD SIDS Report 2003 p5
  •  “None of the propylene glycol ethers have been shown to bioaccumulate in terrestrial species and they appear to present little exposure hazard to either flora or fauna.”  -UNEP UNEP OECD SIDS Report 2003 p44
  • “Unlikely to persist in the environment.”  -UNEP UNEP OECD SIDS Report 2003 p4

Also worth considering:

  • The U.S. Environmental Protection Agency (EPA) has determined that propylene glycol ethers are not included within the listed category "glycol ethers" under either EPCRA §313 Toxic Release Inventory or Clean Air Act §112 Hazardous Air Pollutants (both lists include only ethylene glycol ethers).
  • The Illinois Environmental Protection Agency classifies DPnB as a “green” drycleaning fluid.
  • Solvair Cleaning Fluid does not contain chemicals whose use in the Solvair process would be subject to regulation under California Proposition 65 and the California Air Resource Board (CARB) has confirmed that Solvair is an approved technology for use in drycleaning in California.
  • Cleaners in Indiana and New Jersey who have switched to Solvair have received awards for their pollution preventions efforts by their state environmental agencies


The Environmental Defense Fund scorecard site you cited does not have any indication of the source behind their designation of DPnB as a “suspected neuro-toxicant; it appears to be derived based purely on DPnB being a member of the Propylene Glycol family. Solvair LLC is unaware of any information that suggests any relationship between DPnB and hormone disruption or of any relationship between DPnB and neurological or immunotoxic effcts.  As I mentioned in my previous post, we would not have selected DPnB for the Solvair Cleaning System in the first place if such relationships were indicated. To clarify on this matter, we contacted the manufacturer of DPnB, The Dow Chemical Company (DOW). DOW ‘s response, provided by one of its toxicologists, was as follows:

 "There are no studies indicating an effect on endocrine disruption for propylene glycol n-butyl ethers. In several developmental toxicity studies - conducted in different species - no embryo-, fetal- or developmental toxicity was observed. Further, no treatment-related effects on any reproductive parameters were observed in reproductive toxicity screening studies. In an OECD SIDS assessment on propylene glycol ethers (including propylene glycol n-butyl ether and dipropylene glycol n-butyl ether) conducted in 2003 by the U.S. EPA, no concern for reproductive or developmental toxicity was identified for any of the propylene glycol n-butyl ethers. Endocrine disruptors are chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife.   No neurological or immunotoxic effects have been observed with propylene glycol n-butyl ethers in acute and repeated dose studies in different species and via different routes of exposure. Further, based on their chemical structure, glycol ethers are not expected to bind to endocrine receptors."

Although DPnB is biodegradable and has a history of safe use in commercial products, we encourage ongoing research and believe that it is right and sensible to minimize and prevent consumer, worker, and environmental exposure to any process solvent. Therefore, Solvair is a closed loop system and the rinses of the CO2 extraction (drying) process have been designed to be extremely thorough. Pure liquid CO2 is the last substance to touch clothing in the system. 

While “green” can be a matter of definition, we feel that we have successfully developed a technology that addresses a number of environmental issues beyond solvent choice; Solvair:• Uses process liquids that have both beneficial cleaning and environmental profiles in place of solvents of concern.

• Maximizes recovery and reuse of solvents within the machine while preventing emissions.• Uses a closed loop supply delivery and process waste management system as an integral part of machine operation and a mandatory element of system ownership. • Significantly reduces process waste volume; by at least half compared to traditional cleaning, and creates no contact waste -water. Materials that cannot be recycled by the system are removed and further reclaimed off site as much as is practical. The remaining material may be used for other purposes, such as a beneficial fuel.• Reduces supply use and packaging. Solvair only uses ½ a gallon of Solvair fluid per every 1,000 pounds of clothing cleaned. This is half as much of that used by alternative and traditional dry cleaning solvents. It may also reduce energy use and utility costs depending on a cleaner’s previous operation.• Proactively reduces opportunities for operator errors by monitoring all machines remotely via internet and by building routine maintenance into machine operation.

• Removes a wider range of stains and soils in the closed loop machine than other technologies and as a result, cleaners who switch to Solvair use far less stain removal chemicals than any other method.

I want to stress that other ingredients could be used in the Solvair process instead of DPnB because Solvair is a system not a solvent. This is an important distinction. With other dry or wet-cleaning technologies, factors such as solvents, additives, machine design, supply chain and waste management are each separate decisions made by the machine owner or operator. With Solvair, these elements are part of a single unified system, designed to build in both good cleaning and good environmental practices.

I hope this helps answer your questions. Please feel free to contact me if you’d like additional information.


Ashley Bower

Marketing & Communications Manager

Solvair LLC

The Solvair Cleaning System

Hello Krissy,

I am contacting you to provide you with more information about the Solvair Cleaning System and to address inaccurate statements made about the technology in your blog posting, "Green Dry Cleaning?". It is technically inaccurate and potentially misleading to say Solvair uses “glycol ether”. Generally, “glycol ether” is a term used in the media, and elsewhere, to describe ethylene glycol ethers. Solvair does NOT use an ethylene glycol ether; it uses Dipropylene Glycol n-Butyl Ether (DPnB) as a solvent component in its cleaning fluid.

Your source of information appears to have confused the types of glycol ethers, similar to confusing ethanol (drinking alcohol) with methanol (poisonous wood alcohol). By misidentifying the solvent used in the Solvair process as “glycol ether” the article lists health impacts that are not associated with DPnB and the U.S. Environmental Protection Agency (EPA) has made no such statements about DPnB.  We would not have selected DPnB for the Solvair Cleaning System if the health effects mentioned, such as hormone disruption, were associated with DPnB.

In fact, we are confident that all available information indicates DPnB is a safe and appropriate choice for Solvair. DPnB is readily biodegradable into water and carbon dioxide (CO2), has a low vapor pressure resulting in virtually zero fugitive emissions to the environment, is used in a closed loop process, and was deliberately chosen for Solvair due to its superior cleaning ability and history of safe use. Beyond solvent choice, the Solvair system has a number of built in eco-conscious features. For example, it is very efficient; it produces half as much waste and also uses half as many supplies as other methods.

Please note that there is inaccurate information about Solvair on the internet posted by competitors and others who have been misinformed. Most widely quoted is a story on the Green America site. This article misidentifies the solvent used in the Solvair process and, as a result, lists health impacts that are not at all associated with Solvair.  We have contacted Green America to correct this and are awaiting a response. Sierra Club similarly identified the wrong chemical used by Solvair but have since reviewed the data and removed Solvair from an “avoid” list, suggesting instead that consumers consider Solvair when drycleaning is required. Similarly, the Carbon Dioxide Dry Cleaners Alliance now does welcome Solvair cleaners as members.

For more information on Solvair, please visit our website, I think some of your readers who are interested in eco-friendly garment care or green technologies might find this information interesting.  If you have any questions about Solvair or green dry cleaning, please don’t hesitate to contact me.

Thank you,

Ashley Bower
Solvair LLC

Solvair's Source of Chemical Safety Assessment?

Interestingly enough, Dow Chemical Company, which manufactures DPnB says it is a P-series or propylene oxide-based glycol ether. 

Here is a link to the MSDS for DPnB, CAS#29911-28-2, prepared by the manufacturer.

Here is a link to the Product Safety Assesment Sheet for DPnB, also prepared by the manufacturer.

Both do suggest that DPnB does not have the hazards associated with some other glycol ethers.  

The International Chemical Safety Card found on the CDC National Institute of Occupational Safety and Health link is missing information on routes of exposure and effects of short and long term exposure. Here is a link: lists the chemical, using the same CAS# but under one of its other names, as a suspected neurotoxin and states data is lacking and incomplete. 

A Draft Interim REL dated March 2010 posted on the California Air Resources Board site also sites limited acute toxicity data for DPnB.  Here is a link to the REL:

What data did Solvair reference when determining that DPnB was safe and environmentally friendly?

Suzie Blodgett

Green Elements

Thanks Krissy, thats such

Thanks Krissy, thats such good info!



No problem!  I had been

No problem!  I had been curious about those "green" dry cleaners for a while but it's nice to know that there are do-it-yourself alternatives.

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