Notice of Incident

At 12:44 p.m., on Friday, November 13, 2026 ArcelorMittal Dofasco experienced an emission at the No.4 Blast Furnace.

The visible emission was from the Blast Furnace’s “bleeder valves” and lasted for approximately 24 seconds. “Bleeders” are a safety mechanism: Pressure relief valves that open when high pressure is experienced in the furnace.

The total visible emission comprised primarily of carbon monoxide, carbon dioxide and nitrogen. Particulate in the emission is iron ore fines, coke fines, carbon and coal.

The Ontario Ministry of Environment, Conservation and Parks Spills Action Centre has been alerted, and our teams are investigating.