Explosions at both Babine Forest Products and the Lakeland Mill in Prince George are now thought to have originated in contained spaces in which electrical and mechanical equipment were running.
WorkSafe B.C. issued the report last week, following a lengthy investigation into the Jan. 20, 2012 explosion and fire at Babine Forest Products, and more recently the similar tragedy at Lakeland Mill.
While no final conclusions with respect to the cause of both blasts has been determined, WorkSafe B.C. say that in a bid to provide as much commitment as possible to industry, it is now directing sawmill employers attention to similarities that have been observed during the course of both investigations.
"In both investigations, the ignition sources appear to have been located at the conveyor level, where electrical and/or mechanical equipment was in operation in areas contained by walls and equipment. These areas are at the basement or lower level of both of the sawmills under investigation," said WorkSafe B.C. in the report.
Under the directive order that was issued to all sawmill employers on April 26, 2012, WorkSafe B.C.’s officers have been ensuring that sawmill employers are in compliance with that order.
Thirty-six sawmills in the region were inspected, resulting in 59 inspection reports being issued and 23 orders.
WorkSafe BC say that officers will be paying particular, but not exclusive, attention to areas similar to those identified in the Babine Forest Products and Lakeland Mill investigations.
According to WorkSafe B.C., five elements are required for an explosion; fuel, ignition, dispersion, oxygen, and containment.
Earlier this month, WorkSafe B.C. said sawdust is just one of the potential fuel sources being investigated.
Natural gas and propane are also possibilities, however Scott McCloy, WorkSafe B.C. director of communications said no determination of a fuel source has been determined yet.
"We have just pin pointed the area ... not the ignition source and we are still investigating a number of potential ignition sources," McCloy said to Lakes District News.
An expert lab in the U.S. has also been retained to examine the sawdust samples taken from the sawmill for particle size, and the minimum explosive concentration required to cause an explosion.
When asked why WorkSafe B.C. has been able to zero in on a location at the Lakeland Mill much quicker than Babine Forest Products, McCloy, said there are several factors that have lead to an expedited process at the Prince George sawmill.
He said the location and winter weather were significant factors that slowed down the investigative process at Babine Forest Products. "The site was essentially buried and frozen in snow and ice for several weeks which made site access and setting up of facilities at the location for WorkSafe B.C. investigators difficult. Environment Canada advised that the temperature was as low as minus 41 degrees Celsius in the days leading up to Jan. 20, 2012," McCloy said
McCloy said the presence of ice and snow prevented the investigative team from the more ready access to the site that was present at Lakeland Mill. "In addition, Babine Forest Products burned for several days following the explosion," he said.
As reported in the Lakes District News edition of May 9, 2012, water that was used to suppress the fire quickly turned to a thick layer of ice, resulting in investigators chipping away large amounts of ice in order to begin their investigation.
"As a result of these factors, the site safety planning at Babine Forest Products took close to three weeks, while investigators were able to safely access the Lakeland Mill a few days after the explosion."
McCloy also said the mobile facilities used by the investigation team at Babine Forest Products had just been moved back to Prince George, so the facilities were on hand and were immediately deployed to the Lakeland Mill site.
The heavy equipment required for the Lakeland Mill investigation was available in Prince George whereas it had to be brought into Babine Forest Products from Prince George and McCloy said the contracts and other documents that had to be developed for Babine Forest Products were reapplied in the Lakeland Mill investigation, resulting in minimal administration time.
Investigators immediately applied the lessons learned at the Babine Forest Products site to Lakeland Mill, which allowed for many efficiencies in the scene examination there," he said.