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Innovations
A CLEANER
ALT
Canadian health authorities dis- employs more than 250,000
agree with IARC, and don't people, has taken steps to cut
think the evidence is strong back on perc usage. "Perchloro-
enough to label perc a human ethylene use in 1988 was
Liquid carbon dioxide (CO2) is getting seri- carcinogen. Even so, cutting back on approximately 250 million
ous consideration as the dry cleaning fluid perc seems to be a widely accepted pounds in the U.S.; in 1994 it was
of the future. With encouragement from goal, even in Canada. The Ontario govern- 150 million pounds," says Mary Scalco,
the EPA's Design for the Environment pro- ment has already proposed reducing work- director of government relations for the
gram, liquid CO2 could replace per- place exposure from 50 parts per million International Fabricare Institute (IFI), the
chloroethylene-known as "perc" -today's (ppm) during an 8-hour workday to 10 dry-cleaning trade association. She says
dry-cleaning solvent of choice. Perc, a chlo- ppm. improved technology is the primary reason
rinated hydrocarbon, has been linked to While current regulations of the for the decrease. And attempts to develop
cancer and other health problems. Occupational Safety and Health Admini- alternate methods in dry-cleaning are
Based on animal studies and other data, stration (OSHA) limit worker exposure to being explored with the support of several
the International Agency for Research on 100 ppm, the agency is examining evidence agencies, including the EPA, and industry.
Cancer (IARC) calls perc a probable to see if the standard should be changed.
human carcinogen. The EPA puts the sol- "There is a long-standing relationship Liquid CO2
vent in the possible-to-probable category of between the agency [OSHA], the dry- One technology being investigated uses liq-
carcinogens. cleaning industry, and public interest uid carbon dioxide (CO2) as a dry-cleaning
James Huff, a toxicologist with the groups aimed at reducing exposure, says solvent. Hughes Environmental Systems of
NIEHS, says perc-cleaned clothes pose vir- Joseph Cotruvo, who oversees chemical El Segundo, California, has developed a
tually no cancer risk to the wearers; the screening and risk assessment at the EPA's prototype dry-cleaning machine and process
amount of perc on such clothing is probably Office of Pollution Prevention and Toxics. called DryWash. The system, which uses
negligible. The NIEHS has reported, how- The U.S. dry-cleaning industry, which liquid CO2, was exhibited in Milan at an
ever, that rats exposed to perc international dry-cleaning exposi-
vapors have an increased incidence ` tion in March. While the EPA's
of leukemia and kidney tumors, Design for the Environment pro-
and mice similarly exposed have g gram hasnot funded research on
increased numbers of liver tumors. liquid CO2, it has held confer-
Moreover, Huff says, epidemio- ences and encouraged the
logical studies have linked perc- exchange of information about its
contaminated drinking water to potential.
increases in leukemia in an Sid Chao, president of
exposed population cohort and to Hughes Environmental Systems,
increased urinary, bladder, and says liquid CO2 doesn't have the
esophageal cancers in perc-exposed environmental and health draw-
dry-cleaning workers. Other perc- backs of perc. OSHA limits
related cancers include cervical exposure of CO2 to 5,000 ppm
cancer and non-Hodgkin's lym- $/, ;§ for an 8-hour day.
phoma. Because of these data, Liquid CO2 for dry-cleaning
Huff believes occupational expo- would come from industrial
sures to perc do present a hazard. processes, including fermenta-
Robin Hill, a risk manager at What's ilina name? A new technology called DryWash uses liquid carbon tion and ammonia manufacture,
d
Health Canada, says, that dioxide t o clean clothes. that produce CO2 as a waste
488 Volume 104, Number 5, May 1996 * Environmental Health Perspectives
Innovations A Cleaner Bill of Health
-
product. The CO2 would be processed by its prototype machine for the market. Chao garment are comparable [with existing
a gas manufacturer and delivered to dry- says the firm is planning to license the tech- technology]?" wonders Wentz. He notes
cleaners in pressurized canisters, the same nology to a manufacturer and estimates that that liquid CO2 may have some economic
way it is delivered to restaurants. the machines will be ready for sale by 1997. factors in its favor. The shorter cleaning
In dry-cleaning establishments, the liq- cycle means more garments can be cleaned
uid CO2 would be recycled after use and Unfinished Work, Unanswered in less time. Furthermore, labor costs for
purified for reuse. The gas, though, would Quesitions finishing or pressing the garments may be
gradually escape into the atmosphere by But research on the liquid CO2 cleaning reduced, since the garments are cleaned at
adsorbing into clothes and leaking from process is hardly complete. One problem lower temperatures, which reduces wrin-
dry-cleaning drums when they are opened Taylor is working on is the removal of pro- kling. Such factors will help determine if
to remove clothes. Hughes officials empha- teinaceous stains, such as grass stains, lip- the liquid CO2 process will fit within the
size that its DryWash system does not cre- stick, and chocolate. Dry cleaners currently present dry-cleaning infrastructure, says
ate any new CO2. It captures and recycles get rid of these stains by using surfactants Wentz.
what is already produced. Although the to pretreat the stains before the clothes go If the DryWash machines prove too
exact amount of CO2 that would be recap- into the dry-cleaning drums. The problem, costly for individual "mom and pop" dry-
tured per cycle is considered proprietary Taylor says, is that surfactants don't work cleaners (which make up most of the dry-
information by Hughes, Jerome Barton, a well in liquid CO2. He and his colleagues cleaning operations in the United States,
scientist at the Los Alamos National are working to modify the surfactants so according to the EPA), the machines may
Laboratory (LANL) who has worked on the they will. find homes in central facilities, with cus-
liquid CO2 cleaning process, says that the Another concern, voiced by Dale Spall, tomers dropping their clothes off at store-
amount would be "far in excess of 90%." a recently retired chemist who worked on fronts or so-called "dry stores" to be taken
Liquid CO2 would speed dry-cleaning, liquid CO2 at Los Alamos, is that clothes to the central facilities for cleaning. This is
says Chao. "Once the dry-cleaning is fin- colored with vegetable dyes might shrink already a trend in dry-cleaning, says Scalco.
ished, the clothes can be taken out and when cleaned with liquid CO2. But this system may negate some of liquid
need no drying. Because of that there is a While Spall praises the use of liquid CO2's potential environmental advantage
shorter cycle time. We're looking at less CO2 as innovative and says it shows a great by causing increased fuel consumption and
than 30 minutes. The perc-based cycle deal of potential, other dry-cleaning indus- pollution from transporting the clothes,
time is 40 to 50 minutes," he says. try specialists are cautious. Manfred Wentz cautions. A life-cycle study of fac-
Moreover, liquid CO2 can clean items Wentz, vice president of research and tors such as these would have to be done to
that perc-based systems can't, says Jack development at R.R. Street and Company, assess the advantage of liquid CO2 from an
Belluscio, CEO of Caled Chemical which makes and distributes dry-cleaning environmental perspective.
Company, which makes dry-cleaning addi- chemicals and additives, says additives have
tives and is a partner with Hughes in to be developed to prevent stains removed Wet-cleaning
developing the liquid CO2 process. Liquid by liquid CO2 from being redeposited on Wet-cleaning is another method being
CO2 can clean leather, suede, and fur, clothes during the cleaning process. While examined to replace perc. Highly touted by
which perc-based systems typically can't, he says research of such additives is being the environmental activist group Green-
says Belluscio. Also, unlike perc, liquid pursued, "nothing has been adequately
CO2 won't dissolve sequins. documented yet. I think the problem can
Since 1994, Hughes has been working be overcome but it requires a systematic
to develop the liquid CO2 technology for analysis of the liquid CO2 process." Chao
dry-cleaning under a Cooperative Research disputes this statement: "Our technology is
and Development Agreement with the such that it minimizes the redeposition of
LANL. Researchers at the LANL, funded dirt. Our tests indicate that it is better than
by the Department of Energy and the the perc process."
EPA's Environmental Technology Besides performance, other questions
Initiative, have been doing the basic and remain about how a liquid C02-based sys-
applied research to determine how well tem would fit into the operations of the
CO2 performs as a solvent. Because liquid approximately 30,000 dry-cleaning estab-
CO2 is nonpolar, it dissolves organic com- lishments in the United States.
pounds, including many materials that Cost is one crucial concern for dry-
commonly soil clothes, and releases them cleaners. "Commercial dry-cleaning is not a
from the surface of garments. high-profit business, and many dry-cleaners
"We have found that CO2 is very effec- are barely able to stay in business," states a
tive in removing oils, greases, sweat, etc.," 1995 EPA profile of the trade. Acording to
says Los Alamos chemist Craig Taylor of the EPA report, the cost to start up a dry
the tests performed on swatches of clothes cleaning business in 1993 was $113,000.
in a 60-liter drum. "By using agitation, we Scalco says that she's seen no informa-
find that we get good removal of soils and tion on the cost of liquid CO2 machines
particulates." During the process, clothes from Hughes, but "for liquid CO2 [to be a
are soaked in a liquid CO2-filled drum. viable option] you have to have equipment
Then liquid CO2 is sprayed through noz- that's affordable. That's probably the High-tech soap and water. (left to right) Plant
zles onto clothes to agitate them and biggest thing right now." manager Ann Hargove, owner Noam Frankel, and
remove dirt. "Can we provide a system where the project coordinator Jo Patton are testing a wet-
Hughes doesn't plan to actually produce unit costs per pound for producing a clean cleaning method at The Greener Cleaner.
Environmental Health Perspectives * Volume 104, Number 5, May 1996 489
Innovations * A Cleaner Bill of Health
peace, this European-developed method
uses water and specially designed soaps
instead of solvents to clean clothes.
The machines that do the cleaning are EnvoncntGCnadi.: Pinalreport for the green dean project. OttwaEniroment
sophisticated washers and dryers in which
humidity, agitation, and heat are computer
controlled. "By controlling all those factors ARMngahon ithe evalutin of carcinogic risk to humans, Vol63.
in a better way, it's possible to clean T; achkhLyen& Lyon:lnternational Ageqr Research on Cancer, 19952;
y for
clothes with water that used to be dry-
cleaned," says Jack Weinberg, a campaign- Phelps MR Hogan M , Snowden-Swant U,DBarton JC LaInt, Spll WI). Waste
er against toxic chemicals for Greenpeace. n usn carbnn di xi a: solvrent susiut o precisio ening -applica
Wet-cleaning, or wet wash as it is Ctions4. Richand WAaii NrhetLbaoy; 1994.
0*
sometimes known, is used in Germany and W tz l n w &ix. Npiville, ILR.R Str & Co.,
Austria and has also been tried on a
demonstration basis in the United States
and Canada. WeissNSCancerin relation tooccupational exposure toperchoroethene. Cancer
With funding from the EPA, Green- Causes;f2:(5
Cnrl;60:257-;266 (1995)
peace, and the Center for Neighborhood
Technology (CNT) in Chicago have been
examining how well wet-cleaning cleans In Canada, a wet-cleaning demonstra- exposure, the report stated.
clothes in a study with the Greener tion project begun in 1994 and funded in Wet-clean machines cost between
Cleaner, a private dry-cleaning business part by the government reported that $15,000 and $20,000, and dryers between
that has been operating since May 1995. 30-80% of garments currendy dry-cleaned $4,000 and $18,000. The Canadian report
The study is part of an agreement between can be satisfactorily wet-cleaned, a figure far says the "initial investment in water-based
Greenpeace, the CNT, and the IFI to greater than the 3-15% of clothes (exclud- technology is considerably lower than for
assess perc alternatives. ing shirts) now cleaned in water at dry- new perc equipment." The report, however,
Jo Patton, CNT project director for the cleaners. A report on the project, which calls for more information on the financial
wet-cleaning demonstration, says the wet- involved six cleaning facilities, concluded, feasibility of using wet-cleaning technology.
deaner has successfully cleaned virtually all however, that wet-cleaning "does not appear Although perc is currently the dry-
garments brought to it, rejecting only about to be a complete replacement for perc." The cleaning solvent of choice, according to
one-tenth of a percent because tests at the report also concluded that higher labor costs Scalco, it's clear that governments, envi-
store showed that dyes would run. She says may accompany wet-cleaning because wet- ronmentalists, and the dry-cleaning indus-
wet-cleaning has been able to clean clothing cleaned clothes can require increased hand try are choosing to look for alternatives
made of wool, silk, rayon, cotton, and finishing. Wet-cleaning does, however, offer and ways to reduce its use.
blends of fabrics. Weinberg claims that even decreases in electric and chemical use and
leather can be wet-cleaned satisfactorily. removes the health problems linked to perc Harvey Black
The Coastal Society
5eeking Balance: Conflict, Resolution and Fartnership
15th internationaI Conference
July 14-17, 19,90
5eattle, Washington
Megan P. Bailiff, Conference Chair
The Coastal Society 15th nternational Conference
dlo Washington Sea Grant l2rogram
3716 Brooklyn Ave. NE
Seattle, WA 9&1O5
P'hone: (206) 6&5-110 Fax: (206) 6&5-03&O
mmbailiff0u.washington.edu
490 Volume 104, Number 5, May 1996 * Environmental Health Perspectives
