06 June 2025

We sincerely apologize once again for the concern and inconvenience caused to our neighbors, relevant authorities, customers, and all other stakeholders by the fire that occurred on Tuesday, May 20, 2025, at our Casting and Rolling Plant, Osaka Works (Konohana-ku, Osaka).

Since the fire, we have been investigating the cause of the incident and implementing measures to prevent its recurrence while seeking guidance from the relevant authorities. We would like to once again report the circumstances of the incident, the cause of the fire, and measures to prevent recurrence, and announce that the plant was restarted on Friday, June 6, 2025.

Our company will strive to strengthen incident prevention by thoroughly implementing measures to prevent recurrence, as well as identifying and mitigating similar risks throughout our company, to create a workplace that prioritizes safety and aims for zero incidents.

1. Date and Time of Incident
Tuesday, May 20, 2025, at approximately 5:00 p.m. JST
(The fire was confirmed extinguished as of 5:30 a.m. JST on Wednesday, May 21.)

2. Location of Incident
Casting and Rolling Plant, Electric Conductor Division, Osaka Works (1-1-3, Shimaya, Konohana-ku, Osaka 554-0024)

3. Production Item
Copper wire material (wire rod)

4. Casualties
None

5. Physical Damage
Burn damage to the ceiling and exterior walls of the building around the exhaust duct outlet.
(There was no direct damage to the production facilities.)

6. Cause of Occurrence
According to the fire department's on-site inspection and our internal investigation, we estimate that deposits of copper oxide, iron oxide, carbon, and other fine powders accumulated around the exhaust duct outlet from the casting machine ignite d due to high temperatures, resulting in burn damage to the ceiling and exterior walls of the building around the duct outlet.

7. Prevention of Recurrence
A newly designed exhaust duct has been installed to prevent high temperatures within the duct and the accumulation of combustible materials.  In addition, the installation of the new duct was completed after notifying the fire department, followed by their on-site confirmation.

We will continue to prioritize safety measures in our business activities.
We sincerely appreciate your continued understanding and support.


Related Press Release:
Title: Fire Incident at Casting and Rolling Plant, Osaka Works
URL: https://sumitomoelectric.com/press/2025/05/prs033
Date: May 23, 2025