What type of chemicals are used in dry cleaning?

Answer 1

One of the chemicals that is used in dry cleaning is called Trachloroethylene, also known as perchloroethylene (or "perk"). Most dry cleaners used it because it gets rid of stains from delicate materials. about 85% of dry cleaners now use perc.

also..........

Glycol ethers (dipropylene glycol tertiary-butyl ether) (Rynex)(Solvair) --- In many cases more effective than perchloroethylene (perc) and in all cases more environmentally friendly. Dipropylene glycol tertiary butyl ether (DPTB) has a flashpoint far above current industry standards, yet at the same time possesses a degree of solvency for water-soluble stains that is at least equivalent to, and in most cases better than, perc and the other glycol ether dry cleaning solvents presently in commercial use. A particular advantage of the DPTB-water solutions of the Rynex product in dry cleaning is that they do not behave like a typical mixture, but, rather, the behavior is the same as a single substance. This permits a better-defined separation upon azeotropic distillation at a lower boiling point and also facilitates reclamation more effectively, at a level of 99% or greater, and also enhances purification using conventional distillation techniques.[4]

Hydrocarbon --- This is most like standard dry cleaning, but the processes use hydrocarbon solvents such as Exxon-Mobil's DF-2000 or Chevron Phillips' EcoSolv. These petroleum-based solvents are less aggressive than perc and require a longer cleaning cycle. While flammable, these solvents do not present a high risk of fire or explosion when used properly. Hydrocarbon also contains volatile organic compounds (VOCs) that contribute to smog.[5]

Liquid silicone (decamethylcyclopentasiloxane or D5) --- gentler on garments than Perc and does not cause color loss. Requires a license be obtained to utilize the property of GreenEarth Cleaning. Degrades within days in the environment to silica and trace amounts of water and CO2. Produces nontoxic, nonhazardous waste. Toxicity tests by Dow Corning shows the solvent to increase the incidence of tumors in female rats (no effects were seen in male rats), but further research concluded that the effects observed in rats are not relevant to humans because the biological pathway that results in tumor formation is unique to rats.[6](170.6 °F/77 °C flash point).

Modified hydrocarbon blends (Pure Dry)

Perchloroethylene --- In use since the 1940s, perc is the most common solvent, the "standard" for cleaning performance, and most aggressive cleaner. It can cause color bleeding/loss, especially at higher temperatures, and may destroy special trims, buttons, and beads on some garments. Better for oil-based stains (which account for about 10% of stains) than more common water-soluble stains (coffee, wine, blood, etc). Known for leaving a characteristic chemical smell on garments. Nonflammable.

Liquid CO2 --- Consumer Reports rated this method superior to conventional methods, but the Drycleaning and Laundry Institute commented on its "fairly low cleaning ability" in a 2007 report.[7] Another industry certification group, America's Best Cleaners, counts CO2 cleaners among its members. Machinery is expensive---up to $90,000 more than a perc machine, making affordability difficult for small businesses. Some cleaners with these machines keep traditional machines on-site for the heavier soiled textiles, but others find plant enzymes to be equally effective and more environmentally sustainable. CO2-cleaned clothing does not off-gas volatile compounds. CO2 cleaning is also used for fire- and water-damage restoration due to its effectiveness in removing toxic residues, soot and associated odors of fire.

Wet cleaning --- A system that uses water and biodegradable soap. Computer-controlled dryers and stretching machines ensure that the fabric retains its natural size and shape. Wet cleaning is claimed to clean a majority of "dry clean only" garments safely, including leather, suede, most tailored woolens, silk, and rayon. (Neckties seem to be the one exception.) Most perc cleaners use wet cleaning on some garments, but there are only about 20 exclusive wetcleaners in the U.S.