From approximately 6:30 p.m. to 8:30 p.m. on Monday, March 20, ArcelorMittal Dofasco experienced a series of eight short visible emissions from the basic oxygen steelmaking plant.

An unexpected issue in the process required the KOBM furnace to be emptied, which caused the emissions. Emissions from basic oxygen steelmaking are comprised mostly of iron oxide and calcium carbonate dust and are an orange-brown colour due to the oxidized iron in the particulate matter.

The Ministry of Environment, Conservation and Parks was notified immediately and teams worked to remedy the situation quickly, returning to normal processes. In addition, a root cause analysis is being undertaken to ensure this does not happen again.

About ArcelorMittal Dofasco

About ArcelorMittal Dofasco ArcelorMittal Dofasco is Canada’s largest producer of flat carbon steel and is part of the world’s largest steel and mining company. Headquartered in Hamilton, ON, with more than 4,500 employees each year we ship 4.5 million net tons of high-quality flat carbon steel to partners in automotive, energy, packaging and construction which are used in increasingly lighter, stronger and more sustainable products – from cans to cars. Our purpose is to produce ever smarter steels that have a positive benefit for people and planet. High performance steels made using innovative processes which use less energy, emit significantly less carbon and reduce costs. Steels that are cleaner, stronger and reusable. With steel at our core, our inventive people and an entrepreneurial culture at heart, we will support the world in making that change. This is what we believe it takes to be the steel company of the future. For more information about ArcelorMittal Dofasco, please visit:

ArcelorMittal Dofasco
View all Press Releases