Excerpt from the OH&S Canada Magazine
More than a thousand workers were sent home from Suncor Energy Inc. Millenium Coker Unit about 25 kilometres north of Fort McMurray, Alberta after a fire broke out.
At approximately 6:00 am on October 2, 2007, a fire ignited in a drum at the coker unit, says a statement issued by the Alberta Energy and Utilities Board. There was one minor injury stemming from the incident, the board reports.
The vicinity was immediately evacuated after the fire was detected in the coker, a key processing unit in an oil sands upgrader, says Suncor Energy spokesperson Pattie Lewis. It took about 45 minutes to extinguish the fire, adds Alberta Environment spokesperson Josh Stewart,
Once the fires were put out, Lewis says the evacuation area was expanded as a result of the release of hydrogen sulphide (H2S) among other gases. It was decided that production would continue.
As a precautionary measure, however, “we restricted access to the site to what I would call operating personnel only — the smallest number of people that we need to have on site in order to operate the site reliably,” Lewis says.
The evacuation order was lifted at noon.
We’re looking at whether or not there was a hydrogen sulphide leak, or if something beforehand was connected with the fire,” Stewart says.
Hydrogen sulphide is a flammable, colourless gas whose smell as low levels is similar to that of rotten eggs, Northern Lights Health Region notes in an advisory. Workers exposed to H2S may suffer eye, nose or throat irritation.
In high concentrations, adds an information sheet from the National Ag Safety Database in the United States, the ability to smell the gas is quickly lost. “It will lead to almost instantaneous poisoning and death. High concentrations will result in the complete arrest of respiration.”
H2S levels were 21 parts per billion, (ppb) after the fire. The highest levels for the day read about 81 ppb, recorded before the fire.
This report came from the archives of the OH&S Canada magazine, the December edition. I wanted to identify another report from the past to show that our country still has a long way to go.
H2S is a nasty type of gas one that attacks the breathing centre of the brain. 10ppm is the legal limit defined in our Ontario regulation 83, TWAEV, or ‘Time Weighted Average Exposure Value’ and listed at 15ppm at STEV, or ‘Short Term Exposure Value’. TWAEV is defined as the average exposure of either a 40 hour work week or an 8 hour day. STEV is defined as the exposure listed for a 15 minute period.
I was not totally surprised to see this report and the haste the government took to get the company back to work. Ask anyone that has come into contact with H2S and they will tell you that the small amount needed to kill is scary. In comparison, carbon monoxide (CO) exposure is listed at 25 ppm, recently lowered from 35 ppm, approximately twice that of H2S. As you can see, the ACGIH, the ‘American Conference of Governmental Industrial Hygienists’, has put together a list of over 600 biological and chemical agents, for all companies to use to better protect their workers. Suncor would do well to have their people go over the listing to better prepare itself for any other disaster that may befall them.
It has come across my desk that the province of Alberta is quietly improving its health and safety reputation by issuing over 200 work orders during a recent blitz. Now comes the hard part, ‘ENFORCEMENT’. Let’s see how they do.
Remember — In Ontario, “ALL Accidents are Preventable”
‘Work’ and ‘Play’ safe.
Daniel L. Beal
CHSEP – Foundation Level
VP & Senior Trainer