POSCO Holdings (POSCODX Subsidiary) Accident Report (Form 6-K)

This filing discloses a Serious Industrial Accident that occurred on November 5, 2025, at the Pohang Works, involving subsidiary POSCODX.

• Incident: Inhalation of acidic fumes from a pipe leak at the Stainless Steel Annealing and Pickling Plant.
• Impact: 1 fatality and 3 injuries reported.
• Regulatory Action: The Ministry of Employment and Labor has been notified and conducted a site inspection.

The company is mandated to establish measures to prevent recurrence. This event highlights a significant **o