Mitsubishi Materials executives could face charges over polysilicon plant explosion

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Executives at Mitsubishi Materials are under investigation for possible professional negligence resulting in death or injury following a fatal explosion at a silicon processing plant in Mie prefecture, Japan.

The explosion, which occurred in the afternoon of 9 January as the housing on a heat exchanger was being cleaned, killed five workers and injured a further 12 at the facility in the city of Yokkaichi. The accident is thought to have occurred following a reaction involving trichlorosaline.

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According to daily newspaper Asahi Shimbun, Yokkaichi City Fire Dept and Mie Prefectural police investigated the factory on suspicion of professional negligence resulting in death.

Mitsubishi Materials company president Hiroshi Yao apologised publicly for the accident at a press conference in the hours following the blast. Yao stated in the conference that safety measures at the plant may need to be reviewed.

Mitsubishi Materials also announced to the Japanese press that members of the company’s executive board would take cuts to their monthly remuneration of up to 30% by way of accepting responsibility. The company also appointed new management to oversee the Yokkaichi plant.

Subsequently, local police entered the factory over the weekend and took materials pertaining to their investigation into the cause of the accident. Press reports indicated that manuals provided by the company were found to not contain adequate safety advice.

Early reports from the investigation also stated that the heat exchanger housing appeared to have not been cleaned since 2006.

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