Notice Regarding the Toyama Plant Fire Accident (Final Report)
Nippon Carbon Co.,Ltd.
Toyama Plant (27 Kōnai, Toyama City, Toyama Prefecture); graphitization furnace equipment used in the manufacturing process for artificial graphite electrodes
Volatile components generated by products undergoing heat treatment in the graphitization furnace accumulated inside the furnace, causing a rapid increase in pressure and an explosion that ejected high-temperature coke. The coke came into contact with a nearby water pipe used to cool electrical components, melting the pipe. Water then flowed into the furnace and instantly vaporized and expanded, resulting in the ejection of a large amount of coke, the company believes.
¥803 million (including restoration costs; recorded as an extraordinary loss for the fire)
Consolidated financial results for the fiscal year ending December 2025
Related procedures
On-site inspection and investigation by the fire department
Fire department
Company response
The fire department's on-site inspection and investigation have been completed
(1) Change in the graphitization furnace charging method; (2) installation of covers to prevent coke ejection; (3) changes to the specifications and location of the water pipes
The company will implement measures to prevent recurrence in preparation for resuming operations and will work to ensure safe operations. The impact on the supply chain for artificial graphite electrodes is expected to be extremely limited, through the use of other production facilities and other measures.
| Item | Details |
|---|---|
| Event name | Notice Regarding the Toyama Plant Fire Accident (Final Report) |
| Date of occurrence | 29 August 2025 (Friday), 7:16 a.m. |
| Subject Entity | Nippon Carbon Co.,Ltd. |
| Target Locations / Products | Toyama Plant (27 Kōnai, Toyama City, Toyama Prefecture); graphitization furnace equipment used in the manufacturing process for artificial graphite electrodes |
| Cause | Volatile components generated by products undergoing heat treatment in the graphitization furnace accumulated inside the furnace, causing a rapid increase in pressure and an explosion that ejected high-temperature coke. The coke came into contact with a nearby water pipe used to cool electrical components, melting the pipe. Water then flowed into the furnace and instantly vaporized and expanded, resulting in the ejection of a large amount of coke, the company believes. |
| Amount of Impact on Business Performance | ¥803 million (including restoration costs; recorded as an extraordinary loss for the fire) |
| Accounting period in which recognized | Consolidated financial results for the fiscal year ending December 2025 |
| Type of litigation or proceeding | On-site inspection and investigation by the fire department |
| Court or authority | Fire department |
| Investigation structure | The fire department's on-site inspection and investigation have been completed |
| Measures to prevent recurrence | (1) Change in the graphitization furnace charging method; (2) installation of covers to prevent coke ejection; (3) changes to the specifications and location of the water pipes |
| Outlook | The company will implement measures to prevent recurrence in preparation for resuming operations and will work to ensure safe operations. The impact on the supply chain for artificial graphite electrodes is expected to be extremely limited, through the use of other production facilities and other measures. |
Items this document does not state (13)
These are items the company does not state in this document. We do not leave them blank, nor fill them in from other sources or by inference.
The reasons the company gives
The company's own explanation, not something inferred from the numbers.The company believes that volatile components from the products accumulated inside the graphitization furnace, causing pressure to rise and an explosion that ejected high-temperature coke. The coke came into contact with a nearby water pipe, causing water to flow into the furnace and instantly vaporize and expand, which resulted in the ejection of a large amount of coke.