Carcinogens Found at Semiconductor Manufacturing Factories

7th, February, 2012

Occupational Safety and Health Research Institute (OSHRI), KOSHA released the result of research on working environment in the semiconductor plants, which begun in 2009. It had been conducted as part of following up studies, which was planed according to the results of the epidemiological cohort study for leukemia cases at semiconductor industries in 2008.

In this study, the working environment had been measured for 5 fabrication lines and 4 assembly lines in 3 factories. The research team investigated exposure level of carcinogens related leukemia, such as benzene, formaldehyde and ionizing radiation.

According to the research’s result:

1. It was identified that benzene was found at fabrication line and some other process of the assembly line. Although benzene was not used in this process, it was generated as byproduct with volatile organic compounds by the chemolysis of resin. The amount of benzene from N.D.(not detected) to 0.00038 ppm in the fabrications and was from 0.00010~0.00990 ppm in the assembly line. OSHRI recommended the industry to improve the workplace to reduce the carcinogen.

2. Formaldehyde was another byproduct. Around 0.001 to 0.004 ppm of formaldehyde was found at the fabrication line and there is no difference that in ambient air.  The amount of the formaldehyde released at the assembly line was some 0.002 to 0.015 ppm exceeding a bit the amount of the natural level in the air.

3. Ionizing  radiation reached 0.011 to 0.015 mSv/yr at both the wafer fabrication line and  assembly line, which was below the personal exposure dose limit, 50mSv/yr.

4. Arsenic is known to cause lung cancer, was found at ion implantation process. In some implantation maintenance process, 0.001 to 0.061mg/m3 of arsenic was found which exceeds the occupational exposure limit, 0.01mg/ m³.  In particular, higher risk of exposure to workers of subcontractors in the ion implantation maintenance process requires urgent measures.

The OSHRI plans to distribute health protection guide for workers in the semiconductor sector, based on the result of the research, within the first half of this year.

The Ministry of Employment and Labor (MOEL) believes that this research is very meaningful saying that it revealed possibility of generating carcinogen during the working process, adding that the three subject companies need to improve ventilation facility; to replace hazardous substances with safe materials; to monitor the work environment; to keep the special medical examination for workers and finally to introduce countermeasures to protect workers of subcontractors.

MOEL announced that overall semiconductor sector’s working environment will be inspected and recommended the industry to have the risk assessment system based on the results of this research.