Commercial dry cleaning machines are more common in everyday life, dry cleaning from Europe, previously also tried different dry cleaning agents, such as gasoline, carbon tetrachloride, trichlorethylene, trichlorotrifluoroethane and so on. The longest used is dry cleaning agent - tetrachlorethylene, which has so far been grown for 70 to 80 years in many developed countries in Europe, Australia and North America. Tetrachlorethylene Commercial Dry Cleaners still holds more than 80% of the share. Since tetrachlorethylene has a micro-toxicity, long-term exposure to tetrachlorethylene is harmful to health. Although domestic environmental protection does not limit the concentration of tetrachlorethylene, the design and use of dry-cleaning machines should be considered so that the operator Avoid or reduce exposure to tetrachlorethylene. Therefore, many countries in the world have made regulations on the allowable concentrations of tetrachlorethylene gas in the ...