SUDBURY, Ont. — Toxic gas that leaked from a Sudbury mining facility early Thursday has dissipated and no longer poses a risk to the community, the mining company said.
Residents near the Vale facility at Copper Cliff had been told to stay inside with the windows and doors closed due to a release of nitrogen dioxide.
A piercing alarm went off just after 6 a.m. and at one point, a yellow plume was seen over the town. Roads around the facility were closed to traffic as a precaution.
By 8:30 a.m., the leak was contained to the facility and the emergency called off, Vale said in a statement.
No injuries have been reported.
“For all intents and purposes, it’s all done,” spokesman Cory McPhee said. “At this point in time, it’s just Vale monitoring the situation and launching an investigation into exactly what happened.”
The plant was in the process of being shut down for planned maintenance “so it was probably something related to that work,” he said.
Nitrogen dioxide affects the respiratory system and can be fatal in large doses.