GreenEarth Cleaning is a patented process for drycleaning using liquid silicone (decamethylpentacyclosiloxane, or D5), a clear, odorless, non-toxic solvent solution. D5 degrades into silica (SiO2) and trace amounts of water and carbon dioxide within days if spilled or disposed of. There are currently more than 1,200 drycleaners using D5 worldwide.
Alternatives to perchloroethylene
The standard chemical used in drycleaning is perchloroethylene (commonly called perc), a chemical that produces toxic waste, and is classified as a probable human carcinogen and Toxic Air Contaminant by the EPA.[2] There are roughly 30-35,000 dry cleaning establishments in the United States. Perchloroethylene has been the solvent of choice for drycleaners since the 1950’s (more than 80% of dry cleaners in the United States use it). Concerns about perc were first raised by the scientific community in the 1970’s, but viable alternatives did not exist until the late 1990’s. In January 2007, the California Air Resources Board passed the nation’s first statewide ban on perc, initiating a 15 year phase-out of chemicals and equipment. Massachusetts, New York and New Jersey are considering similar bans.
Hydrocarbon
Sold by Exxon-Mobil under the brand name DF-2000, is currently the primary alternative solvent to perc in use by dry cleaners. It is classified as a volatile organic compound, and it is listed by the EPA as a neurotoxin and skin and eye irritant for workers. Dry cleaning operators often market DF-2000 as an “organic” cleaning technique because, like perc and gasoline, it is a chemical that contains a chain of carbon (the scientific meaning of “organic”). Hydrocarbon solvent is popular with operators because it requires less change and capital expense.
Wet cleaning
A non-toxic, water-based cleaning method that works similarly to home laundry processes with high tech equipment that adjusts the water's Ph and controls humidity while drying, enabling most dry-clean-only garments to be cleaned with water and detergent. While most conventional dry cleaners use wet-cleaning on some garments, there are only a handful of dry cleaners using 100% professional wet-cleaning because it is more expensive and labor intensive.
CO2 cleaning
A liquid carbon dioxide solvent that has minimal environmental impact, but requires equipment that costs up to twice as much as perc machines. Of the approximately 35,000 dry cleaning establishments in the U.S., there are currently 35 that use this process.
D5 solvent properties
D5 solvent is chemically inert, meaning it does not interact with textiles or dyes during the cleaning process. This helps keep preserve the quality of garments, eliminate problems with color loss, maintain a soft “hand” and prevent shrinkage. Unlike petroleum based solvents like perc or hydrocarbon, D5 is odorless and does not leave a chemical smell on clothes.
The International Fabricare Institute (the leading trade association for garment care and dry cleaning) conducted an independent, comprehensive study of the GreenEarth Cleaning system in 2002 to assess its effectiveness in comparison with perc. Tests and evaluations in direct comparison to perc resulted in IFI assessments on six criteria: cleaning performance; ability to handle a variety of fabrics and trims; labor and operating costs; capital costs; health and safety; and potential for contamination. GreenEarth consistently received excellent or good ratings in every category and was found to be a viable alternative for the drycleaning industry. Perc and GreenEarth were concluded to be “virtually identical in terms of the ability to remove stains completely” except in the cases of ballpoint pen and shoe polish stains.
The IFI also tested common materials that pose problems for regular drycleaners, such as leather, faux fur, sequined and metallic garments. Specialty fabrics and decorative trims withstood the GreenEarth process much better than the perc process, which often destroys such items.
A separate independent evaluation of alternative solvents by the IFI in 2007 using the same criteria rated GreenEarth as "good" in the areas of capital costs and health, and “excellent” in the categories of cleaning, environmental safety, ability to handle fabrics and trims and labor/operating efficiency. Perc received a “poor” rating in the areas of health and environmental safety and excellent in all other areas.
Environmental profile
* Is not a VOC
* Is safe for air, soil and water
* Not regulated by the EPA
* Listed as by the EPA as a “SNAP” (Significant New Alternatives Policy) material, a good substance to use in place of ozone-depleting chemicals
* Degrades to silica and trace amounts of water and CO2
* In most areas, requires no special permitting
* Not listed on California Proposition 65
* Can qualify as alternative technology for special funding or tax breaks
Health and safety
D5 has many commercial and industrial applications beyond dry cleaning, and is the base ingredient in many personal care products such as body lotions, soaps, underarm deodorants, and shampoos. It may be listed as dimethicone, polydimethylsiloxane, cyclosiloxane, siloxane or other abbreviations as an ingredient. It is non-toxic, non-irritating to skin, non-sensitizing and has no immunosuppressant effects. More than 30 studies on D5, performed at a cost in excess of $30 million, have been conducted and the data support the safe use of D5 in all of its many applications, including dry cleaning. No other alternative dry cleaning solvent has been subjected to independent health and safety testing.
GreenEarth was given excellent ratings for health and safety by the IFI in its 2007 Alternative Solvent Evaluation. Independent waste stream and air exposure testing, conducted by Severn Trent Laboratories and California Industrial Hygiene Services, confirmed that D5 as used in daily dry cleaning operation exceeds all federal, state and local requirements for water and air safety.
Bioassay study
A 2-year bioassay study was commissioned by Dow Corning, a manufacturer of D5, to study the effects of inhalation of D5 at the highest concentration possible (160 ppm, total air saturation) on lab rats. The rats were exposed to fumes 6 hours a day, 5 days a week, for 2 years. The results, submitted to the EPA under the Toxic Substances Control Act (TSCA) section 8(e) in 2003, showed an increased risk of uterine tumors and increased liver weight in female rats. No effects were seen in male rats. Based on the observed effects, follow up research was conducted by the Silicones Environmental, Health and Safety Council (SEHSC) and concluded that the effects observed in the Dow Corning study were rat-specific, not relevant to humans, and did not pose a health risk to humans. The SEHSC report also pointed out that the concentration of D5 that the rats were exposed far exceeded workplace or consumer exposure from dry cleaning applications; the average exposure to a silicone in a drycleaning plant is less than 3 ppm. The Dow Corning study was a risk assessment of the chemical D5, not its application in a dry cleaning operation. The federal EPA has not moved to conduct a risk assessment of D5 in dry cleaning or other applications.However, the California Air Resources Board (CARB) conducted an 18-month study of D5 as it is used in dry cleaning. In February 2008, CARB concluded that D5 does not pose a health risk to the public, and does not see a need to regulate its use in dry cleaning.
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2 comments:
If D5 does indeed break down into sand, water and carbon dioxide after "a few days in the environment", then why doesn't it do so after repeated uses by the dry cleaner? Further why did Canada, in June of 2008, publish it's intent to ban then use of D5 because it is a persistent bioaccumulator. Doesn't sound like their research shoows it to break down. Green Earth - better than perc sure, but Green - no way.
The breakdown of silicone is through thermal, photo, and biodegradation. GreenEarth cleaning systems use a “closed loop” process that recycles the silicone inside the tank of the drycleaning machine, so degradation in the machine is not an issue. The Environment Canada concerns are based on computer modeling - not empirical evidence, and remains under review. The concern is due to the sheer magnitude of silicones that are released in personal care items and other applications - not drycleaning.
As a dry cleaner, you would already know this. As a CO2 Cleaner you also know that every load of clothes cleaned in CO2 releases CO2 back into the atmosphere. So we wonder about the intent of your post. CO2 is indeed an excellent and viable alternative to perc, but to suggest that GreenEarth is not “green” or imply that CO2 is “greener” than GreenEarth is, in our view, misleading. Certainly CO2 methods use reclaimed CO2, and that is a good thing. But every load of clothes cleaned in CO2 releases approximately 10 pounds of CO2 into the air. Conservatively, the average cleaner does about 2,000 loads a year; at 10 pounds a load, that is 20 tons of CO2 being released into the environment for each CO2 machine operating. If you are releasing CO2 into the atmosphere you are contributing to global warming—after all, other methods of dry cleaning are available that do not contribute to global warming. The vexing truth is, using CO2 technology negates the benefit of reclaiming it in the first place. It is not a net zero effect. It takes energy to capture CO2, and to transport it. Net, while CO2 is one of the very best alternatives we have available, it is not the only one, and it is very expensive, small mom and pop cleaners cannot afford the equipment costs, so it is not as beneficial a green choice as it may appear.
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