How Does the Dry Cleaning Process Work?

When washing clothes at home in the washing machine, water is the main solvent used to clean them. However, many fabrics don’t react well to water. For example, wool and water simply don’t mix. Additionally, there are various stains that water alone isn’t effective at removing.

The term 'dry cleaning' is somewhat misleading because the process isn't actually dry. Instead, it refers to cleaning with chemical solvents instead of soap and water to remove dirt, grease, and stains. One of the first solvents used was kerosene, but it was flammable. After World War II, dry cleaners adopted a solvent called perchloroethylene, or 'perc,' which became the industry standard due to its effectiveness. After cleaning the clothes with the solvent, it's recovered and reused in an extractor, preventing evaporation into the air and reducing pollution. Finally, the clothes are pressed to remove wrinkles and look fresh again.

Perc has a significant drawback as it has been associated with various health risks. In 2020, the EPA began phasing out the use of perc in dry cleaners located in buildings where people live, and California is in the process of eliminating its use entirely. While perc is still commonly used, more environmentally friendly solvents have been introduced to mitigate risks to both workers and consumers. Additionally, the EPA and environmental organizations promote a method known as wet cleaning, which uses water and biodegradable detergents in specialized computer-controlled machines.