A class-action lawsuit has been launched against WorkSafeBC by the employees of two northern B.C. sawmills that exploded in flames within months of each other in early 2012.

A notice of civil claim says wood dust fuelled deadly explosions at the Babine Forest Products mill in Burns Lake and the Lakeland Mill in Prince George killing a total of four men and injuring 42 others.

According to the lawsuit, WorkSafeBC was negligent in its inspections and investigations of the mills and violated its duty to care for the best interests of the workers, causing them physical and psychiatric injuries.

The allegations have not been tested in court.

Last year, two Coroner's inquests into the deaths of the mill workers concluded the deaths were accidental and made recommendations to prevent similar deaths from happening in the future.