Kanto Denka Kogyo details fire cause, eyes September restart for some production

Kanto Denka Kogyo announced the cause of the August 7, 2025, fire at its Shibukawa plant, which resulted in one fatality and one minor injury. The accident occurred when nitrogen trifluoride, pressurized for filling, flowed into an attached pipe due to an unspecified manual valve operation. The gas, expanding from temperature increases, caused a rapid flow with strong oxidizing properties that led to the combustion of the valve's resin components, igniting an explosive rupture of the piping. The company plans to review and revise equipment operating methods to prevent recurrence.

Following safety checks, operations for products other than nitrogen trifluoride have resumed. Of the two nitrogen trifluoride production lines, the undamaged line is set to resume operations on September 17, 2025, after countermeasures are implemented. The damaged production line will resume once necessary approvals from relevant authorities are secured.

The company's accident investigation committee, in collaboration with authorities and external experts, continues its investigation. Kanto Denka Kogyo will promptly disclose any significant impact on its business performance.