Dry cleaning is a process designed to clean clothes and textiles without saturating them in water, using chemical solvents instead. This method is highly effective for removing oil-based stains and preserving the shape of delicate fabrics that water-based washing might damage. While the technology is efficient, the solvents historically chosen for their cleaning power have raised significant concerns regarding human health and environmental safety. The industry has relied for decades on chemicals now recognized as being associated with adverse health and ecological effects.
The Primary Chemical of Concern
The dominant chemical that became the industry standard for much of the 20th century is perchloroethylene, commonly known as PCE or “Perc.” Perc is a chlorinated solvent and a type of Volatile Organic Compound (VOC). Its properties, including being non-flammable and an aggressive solvent, made it highly effective at dissolving greases, oils, and waxes from clothing fibers.
This compound is a colorless liquid that evaporates readily into the air, which is the mechanism by which exposure occurs. The U.S. Environmental Protection Agency (EPA) has classified perchloroethylene as “likely to be carcinogenic to humans” based on evidence from human studies and animal toxicology data. Despite its known toxicity, its cleaning efficiency and low flammability made it the preferred agent for dry cleaning operations until regulatory pressure began to mount.
Health Risks from Exposure
Exposure to perchloroethylene can occur through inhalation of the vapors, dermal contact, or, less commonly, ingestion. The most significant exposure risk is faced by workers in dry cleaning facilities, where chemical concentrations are highest, especially in older machines or poorly ventilated spaces. Consumers face a lower-level risk primarily from off-gassing, which occurs when residual Perc evaporates from cleaned garments carried home.
Short-term, high-level inhalation exposure can cause acute effects, primarily impacting the central nervous system. Symptoms may include irritation of the eyes and upper respiratory tract, dizziness, headaches, and sleepiness. Exposure to extremely high concentrations has even been linked to loss of consciousness, as the solvent acts as a depressant.
Long-term, repeated exposure to lower levels of Perc has been associated with chronic health consequences. Studies have indicated potential for neurological, liver, and kidney damage, as well as adverse effects on the reproductive system. The chronic exposure risk is concerning due to its classification as a likely human carcinogen, with associations linking it to increased risks of bladder cancer, non-Hodgkin lymphoma, and multiple myeloma.
Safer Methods and Industry Shift
Due to the recognized risks of perchloroethylene, the dry cleaning industry is undergoing a transition toward safer, less toxic alternatives. The EPA has finalized a rule under the Toxic Substances Control Act (TSCA) to manage these risks. This regulatory action mandates a complete phase-out of Perc in dry cleaning operations by December 2034, including a ban on its manufacture, processing, and distribution for this use.
Professional Wet Cleaning
One of the most widely adopted safer alternatives is professional wet cleaning (PWC). This method uses water, specialized computer-controlled equipment, and biodegradable detergents. Wet cleaning uses significantly less water than traditional laundry and is recognized by the EPA as one of the most environmentally sound methods available.
Hydrocarbon Solvents
Another option involves the use of hydrocarbon solvents. These solvents are less toxic than Perc and offer similar cleaning power, though they may not be as effective on heavily soiled items.
Liquid Carbon Dioxide Cleaning
Liquid carbon dioxide (\(\text{CO}_2\)) cleaning is also available, using pressurized, recycled \(\text{CO}_2\) as the solvent to clean garments. This process leaves no chemical residue and is non-toxic, but the specialized machinery required can be cost-prohibitive for smaller businesses.
Consumers can take an active role by inquiring with their dry cleaner about the solvent being used. Choosing facilities that have already switched to professional wet cleaning or \(\text{CO}_2\) methods is recommended.