In some cases, pressurized liquid carbon dioxide (CO2) is used as a garment cleaning solvent in place of the tetrachloroethylene (perchloroethylene), or perc, used by traditional dry cleaners. CO2 is a nonflammable and nontoxic gas that occurs naturally in the environment. Under high pressure, it becomes a liquid solvent. To clean garments using CO2, the items are first placed in a specialized machine. The machine creates a vacuum, and once air is removed, the pressure in the chamber is raised by injecting gaseous CO2. Liquid CO2 is added into the chamber, and the garments are rotated in a cycle that lasts between five to 15 minutes. As the clothes are agitated, the liquid CO2 dissolves soils, grease and oils in the fabric fibers. At the end of the cleaning cycle, the liquid CO2 is pumped back into the storage tank to be used again. Any remaining CO2 is released in the air. Green cleaners dry cleaning garments in this process have a larger environmental impact than those using wet garment cleaning methods.
GreenEarth® / Liquid Silicone
The GreenEarth® cleaning method replaces toxic perc with a silicone-based solvent called siloxane, or D-5. D-5 degrades to sand, water and carbon dioxide, and it’s similar to the base ingredients used to make deodorant and shaving creams. It is chemically inert, which means no chemicals mix with your clothes while they are being cleaned. However, a study by Dow Corning (the creator of D-5) found an increased risk of uterine cancer in female rats that were exposed to D-5. This has led the EPA to note that D-5 may be a carcinogen. It’s also worth nothing that the manufacture of D-5 requires chlorine, which, when manufactured, releases the carcinogen dioxin. Green cleaners dry cleaning garments with GreenEarth® also have a larger environmental impact than wet cleaners.