Two workers suffered significant acid burns in a workplace accident at the Molson Brewery Wednesday morning.

Jacques Nadeau of Quebec’s workplace health and safety board said the two men were operating a bottle-cleaning machine at around midnight when they were sprayed with what safety officials described as acid.

"They seemed to have opened a panel, and they were splashed with caustic acid that is used to wash those bottles that have been brought back to the plant," he said.

The workers were taken to hospital for treatment.

One of the workers was burned on more than 50 per cent of his body, said Francis Leduc of Montreal Fire. He didn’t have information on the second worker’s injuries.

An official from Molson Coors denied earlier reports that the substance that burned the workers was acid. The official described it as a "cleaning solution" that was heated to a high temperature.

Two firefighters also received minor burns when they came in contact with the substance while responding to the call. They were treated at the scene.

The fire department’s hazardous materials team responded to ensure all of the spilled material was cleaned up.

The workplace safety board is investigating the incident.