A recent safety blitz of B.C. sawmills found 42 per cent have unacceptable buildups of wood dust, prompting WorkSafeBC to issue immediate stop work orders at nearly a dozen locations.

The provincial regulator has stepped up combustible dust inspections after two deadly sawmill blasts killed workers in Prince George and Burns Lake in 2012. Investigations have pointed to an accumulation of dust in the mills as likely causes of the explosions.

Al Johnson, vice president of prevention services at WorkSafeBC says of the 144 sites inspected between November and January, 61 had problems with dust, 17 were issued warning letters and three were penalized.

"We found dust accumulations in areas that were outside of the normal production areas. Overhead areas, secondary areas, behind electrical cabinets, etc. So, their programs were just not as robust or as sufficient as we need them to be."                         

Johnson says stop work orders are issued at 11 facilities where the hazard is believed to be imminent.

"In most cases, the areas noted were cleaned the same day, allowing production to resume by the next shift. These locations are subject to frequent ongoing inspections to ensure compliance is maintained while mill operators address the challenges noted," said a statement issued by WorkSafeBC.

Two locations were issued a second stop work order, and are now required to report weekly to WorkSafeBC.

But Johnson says he has seen an improvement in the industry when it comes to cleaning up dust since WorkSafeBC boosted its inspection regime.

Last month WorkSafeBC was blasted by B.C. Premier Christy Clark because its inadequate investigation of the Burns Lake explosion prevented prosecutors from proceeding with criminal charges following the deadly explosion.