|
|
A 60-Year Safety Record
Perc?s widespread and successful use over more than six decades has shown that it can be stored and used safely in normal drycleaning practice when proper safety precautions are observed. Drycleaners pay close attention to keeping the workplace as safe as possible, not only because drycleaning businesses are often family owned and operated, but because drycleaners have a moral and ethical interest in proper waste disposal, emission controls, and environmental management. In fact, many DLI member drycleaners are Certified Environmental Drycleaners who have proven knowledge of environmental regulations and safety compliance measures.
Proper handling techniques are required by federal and state law because perc is considered moderately toxic – falling into the same classification as many everyday compounds, including household ammonia and bleach, gasoline, antifreeze, and nail polish remover. Perc is less toxic than many common products, such as mercurochrome. Of course, any of these products could be harmful if you drank them or otherwise abused their use, but with normal use, they are all safe.
Environmentally Responsible
One of the many advantage of perc as a drycleaning solvent is that it does not contribute to smog formation, ozone depletion or the "greenhouse" warming effect. In fact, the drycleaning industry was one of the few industries to actively support the Clean Air Act of 1990, helping to develop tough regulations designed to reduce perc emissions. The industry?s voluntary installation of control equipment has already helped to achieve significant reductions in air emissions. Many DLI member drycleaners have purchased perc leak detectors, perc vapor measuring kits, and vapor analysis badges to closely monitor perc vapors and leaks in their plants.
Risks
The EPA has classified perc as a "possible human carcinogen" because the chemical, just like the once-banned sweetener, saccharin, caused tumors in some rats and mice in laboratory experiments. This classification stems from a policy decision made by the EPA over 20 years ago, when the science of animal testing and its relationship to humans was in its infancy. The policy, designed to err on the side of caution, stipulated that any product that causes cancer when fed in large doses to rats and mice would automatically be considered a carcinogen. Additionally, EPA’s policy is structured so that animal and human studies that show no evidence of cancer are generally disregarded.
Three studies of perc’s carcinogenic potential produced contradictory results, leading the Science Advisory Board of the EPA to suggest that the tumors may have resulted from metabolic processes unique to those rodents, which do not occur in humans. Additional testing showed that perc does not cause the genetic damage that carcinogens normally cause, further indicating that perc is unlikely to pose a human cancer risk.
There is debate regarding the validity of human conclusions based on rodent testing. In 1990, papers in Science and the Proceedings of the National Academy of Sciences argued that it may be the extremely high does given, and not the actual properties of the substance tested, that is carcinogenic. The authors observed that when cells are injured by a heavy does of a chemical, they respond by dividing rapidly in an attempt to repair the organ. That division damages the cells’ DNA, increasing their risk of developing cancer.
To put carcinogenic tests in proper perspective, rodents have also developed tumors form extremely potent carcinogens that occur naturally in many substances, including peanut butter (contains aflatoxin, which is so potent it is used in biological warfare), mushrooms (contain hydrazine), coffee (contains 826 volatile chemicals), and a variety of fruits and vegetables (contain natural pesticides). The tumors develop when the chemicals are administered, like perc, in doses that are equal to or exceed the rodent’s maximum tolerated does.
The only study of perc?s effect ton humans, performed by the National Institute for Occupational Safety and Health (NIOSH), found no increase in any cancer among 600 drycleaning where workers were known to have been exposed to only perc and not other solvents.
|
|
|
 |
|
|
|
