What is perchlorethylene?
Tetrachloroethylene, more commonly referred to as perchlorethylene or PERC, is a man-made substance widely used for dry cleaning fabrics and textiles and formetal-degreasing operations. Although PERC is a liquid at room temperature, some of the liquid can be expected to evaporate into the air producing an ether-like odor;evaporation increases as temperature increases.
Why should I be concerned? Did you bring home a load of freshly dry-cleaned clothes this week? Then you may also have brought home headaches, nausea and an increased risk for cancer. Healtheffects associated with exposure to perchloroethylene include depression of the central nervous system; damage to the liver and kidneys; and impaired memory, confusion,dizziness, headache, drowsiness, and eye, nose and throat irritation. Repeated dermal exposure may result in dry, scaly and fissured dermatitis. There is increasingevidence of human carcinogenicity. The uncontrolled use of PERC has the potential to cause widespread harm to the health of the workers, the people living neardry cleaning shops, the general public, and the global environment. Because significant adverse health effects have been discovered, many countries have imposed stringentregulations for the control of PERC exposures and emissions.
PERC has been a known animal carcinogen since the early 1990s, and the International Agency for Research on Cancer (IARC) recently found adequate evidence to classify the solvent as a possible human carcinogen. In 1995 the IARC classified PERC in group 2A, meaning that it is probably carcinogenic to humans. IARC also has recently classified drycleaning in group 2B, meaning that it is possibly carcinogenic to humans. Cancer mortality research is continuing at the National Institute for Occupational Safety and Health (NIOSH) and other research organizations. In December 1991, the EPA began regulating PERC as a hazardous air pollutant under Section112 of the Clean Air Act. Until the 1980s it was legal for dry cleaners to pour used PERC down the drain. According to a government study, perc now contaminates up to25% of U.S. drinking water.
Modern, closed-loop machines and innovations in vapor recovery equipment and other technologies have reduced occupational exposures and environmental emissions.However, many of the modern controls that have been developed are cost prohibitive for small shops, and some work practices are inadequate.
Who uses it? Today, approximately 90% of US dry cleaners use PERC in their machines.
What Can I Do?
Q. What is wet cleaning?
A. Wet cleaning (by water immersion) is a method to clean garments that normally would have been cleaned in solvent. Wet cleaning became popular recently in Europeand the U.S. because of the strong environmental regulations restricting the use of solvents. Most techniques are similar in that they all use specially formulated wet-cleaning soaps and spotting agents, (consisting of enzymes, peptides, synthetic polymers, and anionic and nonionic tensides). Several measures are used to reducethe risks of clothes damage, the main ones being the following:
* Increased extraction of water prior to drying (The greatest risk to the garment occurs during drying);
* Close monitoring of heat and moisture content during the drying process (moisture sensors control the fabric drying. Temperature in the drum should not exceed 60�C(140�F) for normal garments and 50�C (122�F) for sensitive garments);
* Machines designed to insure low levels of mechanical action during washing through speed reduction and time limits.
Estimates vary as to what percentage of dry-clean only clothes can be effectively cleaned using wet cleaning techniques. According to the Center for NeighborhoodTechnology's initial research, wet cleaning is effective for 75-90% of dry cleaner's business. Currently, there are several hundred companies in the US that clean all or some"dry-clean only" clothes using the wet cleaning method. To find a wet cleaner in your area try it out for yourself, click here.
Q. Are there any problems associated with wet cleaning?
A. Yes. One difference between water and solvents is that water tends to expand natural and cellulose fibers, while solvents do not change the fiber properties. When
natural and cellulose fibers expand, they also wrinkle, lose their strength, shrink, and lose their shape. In general, the higher the synthetic content of the garment, the lowerthe risk of shrinkage through wet cleaning.
Benefits of Wet Cleaning:
* One of the major advantages of wet cleaning is the elimination of dry cleaning solvents, and their associated health and fire hazards.
* Many soils are more easily removed with water than solvent. This is particularly true for water-soluble stains resulting from sugars, salts, drinks, body fluids, starch, milk,and most foods.
* Wet cleaning may help to keep the white garments whiter. Sometimes white garments can be dulled when cleaned with recycled PERC or other solvents.
* Wet-cleaned garments have a more pleasant smell when compared to the chemical odor associated with garments cleaned in solvent.
Drawbacks:
* Dry cleaning solvents do a better job of removing, greases, oils, waxes, and resins.
* Garments made of wool, silk, and viscose rayon cannot easily be immersed in water because of possible garment damage from fiber shrinkage or bleeding of dyes. Most problem garments fall into one of the following categories: suit jackets with front fixing in the construction, coats, items with shoulder pads, and ornate clothing.
Conclusion:
Wet cleaning appears to be a viable option to reduce the usage of drycleaning solvents. However, the technology has not developed to the point where it can completelyeliminate the need for dry cleaning solvents.
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