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Tuesday May 12, 2009

Dirt from dry-cleaning

The chemical used to dry-clean our clothes, if improperly used and disposed of, can threaten the health of both humans and the environment.

YOU know that characteristic sickly-sweet odour that lingers on your clothes after they’ve returned from the dry-cleaners? It may be a reassuring sign that your garments were indeed cleaned thoroughly, but that smell is also an indication of all the processes and chemicals that go into dry-cleaning – chemicals that can cause serious environmental damage if not handled properly.

Not many people realise that something as ubiquitous as dry-cleaning may have far-reaching and potentially serious effects on the environment. The main cause for concern is the cleansing agent commonly used around the world, a solvent called perchloroethylene (perc).

Perc is used in place of water or detergent, and is classified as a chlorocarbon. In the dry-cleaning process, dirty garments are immersed in perc, which is continuously pumped through a filter and recirculated.

The clothes are then circulated in hot air in a dryer to vaporise the solvent remaining in them. The vaporised perc itself is distilled and sent back into the main tank for reuse. This entire process is carried out inside a dry-cleaning machine (see infographic, right). Therefore, the perc supply can actually be recycled for quite a while, though there will usually be some perc residue, or sludge, left behind after each cycle.

Clean clothes, dirty environment

According to Dr Mohamad Pauzi Zakaria, associate professor and co-ordinator of the Centre of Excellence in Environmental Forensics in Universiti Putra Malaysia, perc falls into the category of chlorofluorocarbons (CFCs), which are acknowledged as having a destructive effect on the ozone layer. “CFCs (such as perc) are released into the environment as they are volatile and readily evaporate. These CFCs are transported to the upper stratosphere where they will react with ozone and cause a depletion of the ozone layer.

“This has very serious environmental and health implications. The ozone layer protects humans from exposure to harmful ultraviolet radiation,” says Pauzi.

And like carbon dioxide and methane, CFCs are also greenhouse gases. Many CFCs are banned globally under the Montreal Protocol on Substances That Deplete the Ozone Layer (enforced in 1989) but perc is not of them. Pauzi says perc is less potent than those CFCs with fluorine atoms in the compound, but can nevertheless destroy the ozone layer. “We have to totally ban CFCs to protect the ozone layer,” he stresses.

There are many ways in which perc can be released into the environment during the dry-cleaning cycle. Dr Catherine Yule, deputy head of the School of Science in Monash University Malaysia, says perc that escapes during the dry-cleaning process can pollute buildings, the air, groundwater and soil.

“Perc is highly volatile and so it is difficult to contain and recycle. It can be released during cleaning, purification and waste disposal,” she says.

She explains that this happens in several ways. Firstly, perc is released into the air when it is added to the dry-cleaning machines, and also evaporates from open drums and dry-cleaned clothes. It can further evaporate from clothes that are being transferred from the washer to the dryer, or it can be discharged by the dryer exhaust. Perc can also be released through accidental spills or from leaky tanks and pipes.

“Most of the evaporated perc exits buildings through windows, vents and air-conditioning ducts, but the vapour can also pass through the floors, walls and ceilings of dry-cleaning establishments,” adds Yule. “Perc can remain in the air for nearly a month, after which it breaks down into other chemicals, some of which are also toxic.”

Another source of contamination is when the dry-cleaning process is over, and the solvent is removed to be reused. Yule says that sometimes, the liquid isn’t recycled but simply thrown down the drain. Solid wastes remaining after the cleaning can also be a source of pollution.

Perc is also used in textile mills, metal cleaning operations and rubber coatings factories. It is reported to be the chemical most widely found in groundwater contamination in the United States. Some states there have set target dates to phase out perc, replacing it with less toxic dry-cleaning substances which are now in the market.

The real dirt

Clean spin: Dry-cleaning machines need to be well-maintained in order to minimise the release of perc into the environment.

Those in the dry-cleaning industry acknowledge that perc is damaging to the environment. The product handbook by Dowper, a leading global supplier of perc, for example, emphasises that special care should be taken to prevent the entry of perc into soil, surface water or groundwater, and that failure to do so would result in environmental contamination.

Some of the ways to ensure this is to keep dry-cleaning machines in pristine condition and to properly dispose of used perc. It is also important to store and transfer the solvent in a safe way to minimise its release into the surroundings. The onus of enforcing this in Malaysia, however, seems to be in the hands of the individual business owners.

Big laundry chains here seem to practice self-regulation for the most part, complying with international standards set by their parent companies.

Pressto Asia director Tan Ling Swee says they minimise the release of perc by using the newest available machines and advanced programmes.

“It isn’t prevented 100%, but it is minimised greatly. The machines also minimise the amount of perc going into the garment at every cycle,” he says.

Rajeswaran Muniandi, general manager of Crisp-N-Clean, agrees that the machines and programmes used are very important.

“If there isn’t proper maintenance of the machine, then there is definitely a higher chance of the perc leaking during the process, as well as perc remaining on the customers’ garments. However, we are aware that it can cause environmental and health problems, so we have very strict guidelines to follow.”

Both Tan and Rajeswaran stress that their companies hire contractors who are licensed to dispose of chemical wastes.

Crisp-N-Clean employs Yozai, a company dealing with scheduled wastes (particularly solvent wastes) to handle their used perc. A spokesperson for Yozai explains that the company’s job is to recycle as much of these wastes into usable condition. “A lot of solvent is recoverable, so we distil it and extract the usable amount,” the person says.

After this process, any remaining waste is sent by Yozai to Kualiti Alam (which operates the country’s main hazardous waste treatment and disposal facility in Bukit Nenas, Negeri Sembilan) for disposal.

The spokesperson says Kualiti Alam either incinerates the waste or places it in their landfill.

Tan shares, however, that there is no specific organisation that monitors dry-cleaners in Malaysia. Pressto is monitored by their parent company in Spain while Crisp-N-Clean adheres to the guidelines of the Drycleaning and Laundry Institute International.

This begs the question: who ensures that the many smaller dry-cleaners in the country adhere to the proper usage and disposal of perc?

As it is classified as scheduled waste, perc residue falls under the jurisdiction of the Department of Environment. As licensed businesses, however, laundries and dry-cleaners come under the purview of local authorities.

Therefore, it remains unclear which government agency is responsible for monitoring the usage of perc. Repeated attempts to obtain comments on the issue from the Department of Environment were unsuccessful.

Tellingly, a survey of several laundries in the Klang Valley showed that the owners were quite casual with using this solvent (see sidebar).

Are your clothes making you sick?

Besides the environmental effects, perc is also associated with a host of health-related issues. These occur in two circumstances: firstly, the effect on dry-cleaning workers who are exposed to the solvent daily and secondly, the effect on the consumer, whose dry-cleaned clothes contain and release traces of perc even after they’ve been brought home.

“Perc is toxic to humans, as well as animals and plants. It enters the body when it is breathed in or via contaminated food or water. It does not usually pass through the skin. It can be stored in fat tissue and has been associated with cancers, liver and kidney damage, and respiratory failure,” says Yule. “It has also been implicated in birth defects. People who work in dry-cleaning establishments are most likely to be affected, particularly if the machines are old and not well-maintained and cleaned.”

While there isn’t conclusive evidence linking perc to medical problems, there are numerous studies that suggest this. In the early 1980s, the United States Environmental Protection Agency stated that perc posed a risk to the environment and in 1985, classified it as a possible human carcinogen – a fact the International Association for Research on Cancer concurs with.

The US National Institute of Environmental Health Sciences further states that short-term exposure to perc can cause adverse health effects on the nervous system that include dizziness, fatigue, headaches, sweating, incoordination and unconsciousness, while long-term exposure can cause liver and kidney damage.

The effects seem most pronounced on workers in the industry. A Danish study by Kolstad, Brandt and Rasmussen showed that pregnant dry-cleaning workers are twice as likely to have a miscarriage in comparison to pregnant women in other jobs. Another study by the University of California at Berkeley discovered that male dry-cleaning employees have more sperm abnormalities and a significantly lower sperm count.

Again, companies like Dowper provide ample warning of the effects of over-exposure. The company’s handbook states that perc is hazardous if handled without engineering controls, ventilation equipment and personal protection such as gloves, goggles and respirators.

The guide further says: “When it is used properly by trained personnel and stored carefully in accordance with accepted practice, perchloroethylene should present little or no practical risk to workers. Exposure above guideline levels, however, may cause adverse effects, including anaesthetic or narcotic effects and liver and/or kidney effects.”

Companies like Pressto and Crisp-N-Clean are aware of these risks, and ensure that their personnel are always in their protective gear when handling perc. Tan further says Pressto plants have air-quality testers to monitor the levels of perc in the working environment.

Small neighbourhood laundries and dry-cleaners, however, seem to rarely take such precautions. Here, workers often don’t wear any protective gear, and it isn’t unusual to see buckets or dippers filled with perc sitting out in the open near the machines.

Rajeswaran also explains that the quality of the dry-cleaning machine greatly affects whether perc residue is left on consumers’ clothing.

“The drying process, if done properly with a good machine and programme, ensures that all the perc on the garments is evaporated. When the machine is not well-maintained, however, there is a high chance of traces of solvent left on the clothes,” he says.

The problem, according to Pauzi, lies in murky legislation.

“Dry-cleaning chemicals may have escaped our monitoring activities due to unclear jurisdiction. Our country’s environmental law straddles a wide spectrum of agencies, making it very difficult to focus.

“It is time for us and the authorities to take a closer look at these chemicals, to try and understand their impact on the environment and us. Clear and unambiguous legislation will help.”

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