Perchloroethylene,(C 2 Cl 4), a chlorinated solvent that goes by several other names
including PCE and tetrachloroethylene and several trade names. In the forties and fifties
perc replaced trichloroethylene, which had replaced carbon tetrachloride (both more
hazardous than perc), and is now the solvent used by 90% of dry cleaners in the US.
Perc is also widely used in industry as a degreaser. Annual usage in the US is many
million of gallons of perc. Some of this undoubtedly finds its way into the groundwater
and into drinking water. This cannot be good for the earth or the people living on it!
Chlorinated solvents have been shown to cause cancer in some animals and studies
of workers in the US who are in daily contact with Perc vapor have found
significantly higher levels of esophageal, bladder, tongue, intestinal, lung and
cervical cancer. This is consistent with studies in Canada and the UK.
The US OSHA (Occupational Safety and Health Administration) warns that perc is a
possible human carcinogen (04/15/05) and strictly limits exposure in the workplace.
The International Agency For Research on Cancer classifies perc as a "possible
human carcinogen". (1995). Perc accumulates in body fat. More immediate effects
include nausea, headaches, dizzy ness and drowsiness. As a customer you wont be
exposed to the same levels but it's a good idea to avoid exposure to harmful
chlorinated solvents, and people who are sensitive to chemicals should beware of
contact with garments cleaned by perc.
Like tobacco and alcohol, Perc is not a deadly poison, but it is harmful, and dry
cleaners should be required to provide a written warning to customers, just as
makers of tobacco products and alcoholic drinks are required to do. This warning
should give the “possible carcinogen" status and warn chemically sensitive users
about perc.
For people who are not exposed to perc in the workplace the most likely pathway into the body is through the lungs. You must have noticed the rather unpleasant odor
of newly dry cleaned garments Tests show that, even after a hundred days, 40% of the perc in the garment after cleaning is still present. When you pick up a garment
from the dry cleaners you should take it out of the plastic bag and hang it outdoors or in a well-ventilated area for some days to reduce the amount of perc vapor you
bring into your home. This is especially important for large, heavy items, such as "comforters" and sleeping bags, and when a number of garments are packed in one
bag. People who live over, or near to a dry cleaning operation may be exposed to harmful levels of perc vapor.
NIOSH (National Institute of Safety and Health) studied methods to limit perc
emissions. The study confirmed that technology is available in Europe to do so.
Germany has imposed regulation to mandate use of such technology. This requires
a considerable capital investment, and without similar regulation in the US there is
no incentive to make this investment. Government regulations prohibit the disposal
of perc or water containing perc into a sewer, but these regulations are largely selfenforced.
Sewage treatment does not remove perc and treated wastewater will be
discharged into rivers or the ocean. Perc has been detected in drinking water at
many locations in the US.
Alternatives to perc
Google "perc alternatives" to find alternatives to perc. One "perc free" option is "wet
clean", the use of detergents and water instead of perc. Google "wet clean" for more
information. There are fabrics that are difficult to wet clean without shrinking and
some stains that are easier to remove using perc, but many garments carrying the "dry clean only" label can be safely wet cleaned. New wet clean technology has
tightly-controlled temperatures for washing and drying, which makes if possible to
wet clean some articles that would be difficult to wash using conventional methods.
The most complete page is by the US EPA, (labeled) PDA which gives information
on wet cleaning and also lists providers of non-perc cleaning by state.
Wet cleaning eliminates many of the disposal problems of perc because the
wastewater can be safely discharged into the sewer. Another advantage is that "non
perc" cleaners do not have to register with the EPA.
Another "perc free" method is to launder articles in liquid CO 2 (carbon dioxide),
which is non-toxic but this method is not in widespread use. The dry cleaner I use in
Newton advertises "perc-free cleaning available" but his system uses oil based, not
water based, cleaning fluid.
How to limit exposure to perc
- Buy as few garments as you can, which carry the "Dry Clean Only" label
- Use a "wet cleaner" The US EPA web page lists four wet cleaners in
Massachusetts, including one in Newton: Corner Cleaners, 1301 Washington St,
West Newton.
- Google "wet cleaners" to get more information
- Ask your dry cleaner to offer "perc-free" cleaning.
- Have garments dry-cleaned less often
- Try careful hand washing. For guidelines go to Google: "stain removal
Gilbert Woolley is a retired engineer. He has been a very active member of the
Sierra Club since 1971, and he served on the Sierra Club National Toxics
Committee for six years.
