Everyone has a few garments that they need to dry clean on occasion, even it's just for that one wedding every few years. But the solvent most commonly used in the process, known as "perc," is a known carcinogen. Fortunately, there's a better option available.
A brief (but explosive) history of dry cleaning solvents
Romans were the first recorded civilisation to employ dry cleaning. Their fullonicae, the dry cleaners of the time, employed a mix of urine-derived ammonia and fuller's earth (a type of clay soil containing the mineral palygorskite) to gently scrub wine stains from wool clothing.
It wasn't until the mid-19th century that people stopped peeing on their clothes and switched to modern petroleum-based solvents—by accident. As Rachel Swaby previously explained on Gizmodo:
In the 1800s, a French gentleman named Jolly Belin spilled some kerosene on either a gross tablecloth or some dirty laundry, depending on who you talk to. His clumsy mistake turned up an unexpected result: the oily mixture of hydrocarbons banished the stains already built up on the fabric. Thinking he might have landed upon a better cleaner than soap and water, he started testing kerosene's dirt-removal powers. Pleased with his results, he opened a kerosene-powered cleaning service in Paris-or what's now known as the first ever dry-cleaning establishment.
Kerosene (believe it or not) lifted dirt without messing up the clothing's fibres.
But as effective as these solvents were, they had a nasty habit of expelling highly toxic and explosive fumes. The resulting firestorm of dry cleaning accidents prompted the government to begin regulating the industry as well as the development of less flammable solvents. By the 1930s, the industry hit upon its current gold standard of solvents: perchlorethylene, or perc.
The promise and problem with perc
Perc, as described by the FDA:
It is is a clear, colourless liquid that has a sharp, sweet odour and evaporates quickly. It is an effective cleaning solvent and is used by most professional dry cleaners because it removes stains and dirt from all common types of fabrics. Perc usually does not cause clothes to shrink, nor dyes to bleed. Perc is not flammable, unlike solvents commonly used to clean clothes in the 1930's and '40's. Since perc can be reused, it is a cost-effective and efficient solvent for cleaning clothes. Perc is also a toxic chemical with both human health and environmental concerns.
That's putting it lightly. Long-term, perc has been show to be carcinogenic in both humans and animals; but even very short-term exposure to high concentrations of perc can result in "dizziness, fatigue, headaches, confusion, nausea, and skin, lung, eye and mucous membrane irritation," according to the FDA website. "Repeated exposure to high levels can also irritate the skin, eyes, nose and mouth, and can cause liver damage and respiratory failure. Perc might cause effects at lower levels as well."
And its not just those that come in direct contact with the solvent that are harmed. Lab studies suggest that high-level exposure can cause birth defects, miscarriages, abnormal growth and development rates in foetuses and newborns, reduced fertility, and even death in lab mice.
There have been some case studies of industry workers who seemed to develop cancer at an elevated rate. Human-based studies specific to this chemical have been few and far between, so the link between perc and these symptoms in our species remains inconclusive. Not exactly comforting, nor has it stopped California from banning the solution outright.
What's more, when perc is vented into the atmosphere it breaks down into toxic and ozone-destroying chemicals. If it makes it into the soil, perc is quite toxic to plants. And if it makes its way into streams and waterways, it will kill and sicken marine life because, you guessed it, it's toxic.
Making a clean, green start
Luckily, there are a number of safer alternatives. While systems leveraging liquefied carbon dioxide, glycol ethers, and ultrasonic "wet cleaning" are currently under development, they're all still a ways from hitting market. Today's most widely employed perc alternative is liquid silicone, known as decamethylcyclopentasiloxane or for short, "D5."
This clear, odourless—and non-toxic!— solvent is the lynchpin of the patented GreenEarth Cleaning solution. Not only is it less damaging to fabrics than perc, it does not appear to elevate cancer risks in humans and most animals nor does it produce the same foetal defects. What's more, a 2002 study conducted by the International Fabricare Institute found that D5 and perc to be "virtually identical in terms of the ability to remove stains completely."
D5 does not fall under California's prop 65, one of the most stringent anti-carcinogen laws in the country, nor is it regulated by the EPA. In fact, the EPA has gone and specifically exempted the chemical from VOC regulations as well as designated it a SNAP (Significant New Alternatives Policy) material—one that the agency promotes instead of the older, ozone-depleting solvents.
There are currently 980 dry cleaners throughout the US (more than 1,600 worldwide) that use D5. Unfortunately, as D5 is a newer and less available product, it can cost up to twice the price of traditional chemicals, which has limited its adoption, especially among smaller independent dry cleaners. That expense is also passed along to the consumer. Still, if you don't mind paying a bit extra for the peace of mind that your laundry won't give you cancer or destroy the environment, you can find a shop near you using this locator. [Wiki - EPA 1, 2 - Green Earth Cleaning]