OTSU, Shiga Pref. – A predawn explosion and fire at an aluminum factory in Hino, Shiga Prefecture, on Friday left three workers injured, authorities said.
The blast, which occurred around 3 a.m., badly damaged a 450-sq.-meter steel-frame building owned by Toyo Aluminum K.K.
It also sparked a fire that took about 2 1/2 hours to extinguish, according to police and firefighters. The factory operates 24 hours a day.
The cause of the explosion is under investigation.
Kazuhiko Shinomiya, head of factory operations, speculated that aluminum powder inside a pipe may have generated static electricity and triggered the explosion.
The factory had previously suffered an explosion in February 1997, according to the police.
Two workers handling aluminum powder at the factory, which is located in an industrial park, suffered serious burns, while another employee sustained light injuries from the blast, according to the police and firefighters.
The roof and walls of the building were ripped out and dense smoke and a foul smell temporarily hung over the surrounding area after the blast, they said. Three adjacent buildings also sustained some wall and window damage.
Due to the dangers posed by a potential chemical reaction with water, firefighters used sand and chemical agents to counter the fire. The factory produces aluminum powder for use as a refractory and catalyst.