Removal of Trichloroethylene in the production of car accessories
Trichloroethylene was used in a plant that manufactures car parts to clean steel parts of the air conditioning and assisted driving systems. Trichloroethylene was replaced by a closed washing system based on soap and water.
Closed washing process with soap and water
Trichloroethylene was used in the given section of the plant to clean steel parts. The parts were dipped in a pail that contained the product at high temperature. Steel parts were placed in hanging metal baskets that were immersed in trichloroethylene. After the cleaning process was completed the parts were removed by a plant operator. The operation implied the exposure of workers when they checked the correct development of the process, and especially when the workers had to remove the parts from the basket. The pails were located in a separate area of the department and even though there was an extraction system, trichloroethylene vapours affected the closest workstations. Workers who performed the cleaning operations had personal protection equipment which they did not use because of its discomfort and employers did not force them to wear it.
Safety representatives had concerns about the use of this product for some time. There had been several cancer cases among senior workers and miscarriages among pregnant women. After filling a formal request demanding the substitution of trichloroethylene, the preventive service replaced it to use perchloroethylene, using the argument of its classification only as “possible carcinogen”. The substitution failed as the staff in both sections of the plant reported dizziness, nose bleeding, headaches and other adverse symptoms.
Two incidents occurred with cleaning pails in that period. In one case the pail overheated and smoked the whole area. The second incident was a fire due to technical failure that affected the laboratory rooms located above the work sections. The management suggested repairing the pail but safety reps warned that if they persisted in the use of perchloroethylene they would call for the halt of operations in the affected work stations. The company eventually changed the process and parts are now washed in a pail with soap and water.
The alternative implies the installation of a cleaning machine in each trimming section.
The machines use a water-based, non-toxic cleaner (96% distilled water). Aside from its cleaning function the product is also a lubricant/cooler used in trimming processes which eliminates the use of cooling oils from the process.
The cleaning machines have a system to separate the oils (from the cutting process) and the metal dust from trimming. This procedure helps extend the product’s useful life period. After use the product is recycled in the trimming process.
Trichloroethylene is classified as carcinogen category 2 (category 1B according to CLP Regulation) and perchloroethylene as carcinogen category 3 (category 2 according to CLP).
The company did not comply with Carcinogens Directive recommendations:
(a) limitation of the quantities of a carcinogen at the place of work (especially by replacement)
(b) design of work processes and engineering control measures so as to avoid or minimise the release of carcinogens into the place of work;
(c) evacuation of carcinogens at source, local extraction system or general ventilation, all such methods to be appropriate and compatible with the need to protect public health and the environment;
Risk reduction, cleaner production, use of safer products and better compliance with applicable legislation.
Local exhaust ventilation failed to provide the necessary protection for workers’ health (there were several cases of cancer and miscarriages in the company).
There was a serious risk for workers’ health and safety related to carcinogens exposure at work and substitution was the best solution to the problem.
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Publication or last update: 16.05.2012