How Does Dry Cleaning Work?
Dry cleaning works by using chemical solvents to clean textiles instead of water. In essence, dry cleaning still uses liquid; however, the process is known as dry cleaning simply because the solvents used are not water-based. Such solvents, which are often halides or organohalogens, have a knack for dissolving dirt and grease from fabrics, making them the go-to choice for cleaning delicate textiles. Carbon tetrachloride was once a popular choice, but due to its health risks, it was largely replaced by the solvent tetrachloroethylene. However, tetrachloroethylene is also in the process of being phased out due to evidence of risks to human health and the environment.
The process of dry cleaning begins with the inspection of garments for stains, damage, and fabric type. Stains are treated individually with spot-cleaning chemicals designed for specific types of stains, such as ink, oil, or protein. Clothes are then placed in a dry cleaning machine, which looks similar to a large front-loading washing machine. The machine gently rotates the clothes, soaking them in solvent to dissolve stains. The solvent is drained, and the clothes are gently dried using warm air to evaporate any remaining solvent. Remaining stains are treated again, and garments are pressed, steamed, reshaped, and prepared for return to the customer.
Tetrachloroethylene (also known as perchloroethylene, or PERC), a colorless, nonflammable liquid is the most widely used solvent in dry cleaning. Its popularity stems from its ability to dissolve a wide range of organic substances, making it highly effective at removing stains and dirt. In late 2024 however, the U.S. Environmental Protection Agency (EPA) issued a ban on consumer uses and many commercial uses of tetrachloroethylene; in dry cleaning, the chemical was scheduled to be phased out within 10 years, providing time for transition to alternatives, which include petroleum-based hydrocarbons, silicone-based solvents, and liquid carbon dioxide. Although such chemicals are safer and more environmentally friendly, they also tend to be less effective.