Shell Canada Ltd. and CEDA International Corp. were fined  $90,000 after two workers collapsed on the job at Shell's oil refinery in Corunna.

In early 2013, Shell hired CEDA, an Alberta-based company that provides chemical-cleaning services to industrial facilities, to clean heat exchanger tubes.

On Apr. 26, two CEDA workers were at the refinery cleaning two tubes. The tubes were placed into a vat, which was then filled with a sulfuric acid solution. Just after the acid had been added, the workers' hydrogen sulphide (H2S) monitors sounded.

Both workers suffered dizziness, disorientation and briefly collapsed. A third CEDA employee was able to leave the area. All three workers were taken to hospital and released the same day.

Shell pleaded guilty to failing to provide information, instruction and supervision to a worker to protect the health and safety of the worker. CEDA pleaded guilty to failing to acquaint an employee with the hazard of hydrogen sulphide. 

Shell was fined $40,000 and CEDA was fined $50,000.