Canfor Corp.'s Mackenzie mill.David Ebner/The Globe and Mail
An unprecedented crackdown on safety in sawmills across B.C. after two catastrophic explosions that killed four people has led to the closing of a portion of Canfor's mill in the northern town of Mackenzie.
A chipping unit was shut for five days earlier this month as a result of sawdust built-up, Bruce Clarke, WorkSafeBC's prevention manager for the northern interior region, said on Friday in an interview.
Inspectors went into the mill on May 2 to check out flammable substances and ignition sources as part of a province-wide snap inspection ordered after the second explosion. "They found one area [that caused some concern]and shut it down," he said. When they returned on May 7, the mill was cleaned up to an acceptable standard and the closing-order was lifted, he said.
The Canfor mill was the only one that inspectors so far have shut down as a result of significant sawdust accumulations.
The causes of the explosions at the Babine Lake Forest Products mill in Burns Lake on Jan. 20 and at the Lakeland Mills in Prince George on April 23 have not yet been determined.
However, WorkSafeBC has identified sawdust from processing dry beetle-killed timber as a possible factor in both.
A standard for sawdust build-up was established only after the second explosion three weeks ago. Previously, WorkSafeBC had standards for respiratory exposure to sawdust, but did not have a criteria for sawdust as a potential fire source.
"We set a criteria of one-eighth of an inch," Mr. Clarke said. "This was just a precautionary thing on our part," he added.
"We still do not know for sure [whether]this is a major factor in the explosions or not. We're fairly sure they are contributing factors, but to what level of contribution . . . we won't know until the investigation is done," he said.
WorkSafe B.C. inspected dozens of mills after the explosion in Burns Lake in January. Inspectors identified sawdust build-up as an issue in some, but they were focused on respiratory issues, not fire prevention, he said.
Inspectors at that time did not find many mills with excessive levels of sawdust buildup in the northern interior region, he said. "I'm not saying it was not a problem. At that point, we did not have a criteria to go by," he said. The province-wide number of mills with sawdust problems was not available Friday.
After the second explosion, WorkSafeBC issued a province-wide order on combustible dust and ignition sources. Inspectors subsequently headed out to check 176 mills. Up-to-date statistics on the number of orders that have been issued and the rate of compliance were not available on Friday.
Many of the inspection reports and orders are posted on the WorkSafeBC website. The online posting follows some criticism of WorkSafeBC for not providing easy public access to the inspection reports. Betty Pirs, vice-president of prevention services at WorksafeBC, said on Friday that reports will now be posted at the end of every week.
The reports posted on Friday show that 176 mills have been inspected since the second explosion and follow-up visits to see whether the mills complied with orders have been done at 108 mills.
Numerous infractions and violations of safety standards were identified, including a fire at the Decker Lake Forest Products mill in Burns Lake on March 6. Two workers were treated for mild smoke inhalation in that incident and returned to work.
The postings show that six mills have completed required improvements. Up-to-date records were not available on how many mills have failed to comply.