Kanto Denka Kogyo details fatal plant fire, production impact

Kanto Denka Kogyo Co., Ltd. announced that a fire at its Shibukawa Plant in Gunma Prefecture on August 7, 2025, at 4:31 a.m. resulted in one employee fatality and one minor injury. The fire, which was extinguished by 8:45 a.m. the same day, damaged part of one of two nitrogen trifluoride production lines.

An investigation revealed the fire's cause was an explosive rupture of piping. This occurred when nitrogen trifluoride, intended for high-pressure storage, flowed into attached piping due to an unprocedural manual valve operation. The gas's expansion from a temperature rise and rapid flow ignited resin components within the valve, leading to combustion and the subsequent explosion. The company plans to review and revise equipment operating methods to prevent recurrence.

Operations for products other than nitrogen trifluoride have resumed following safety checks. The undamaged nitrogen trifluoride production line is scheduled to restart after implementing countermeasures, while the extent of damage to the other production line is still being assessed. Kanto Denka Kogyo will disclose any significant impact on business performance promptly.