The smallest-sized wet wood dust is just as explosive as dry wood dust from B.C. sawmills, according to a report prepared by FPInnovations for the provincial sawmill sector.
The surprise finding — which raises questions about the usefulness of misting at sawmills — was part of a first-of-its-kind study in British Columbia ordered after a pair of deadly sawmill explosions in the province last year that killed four workers.
“It was assumed moisture would be a bigger factor,” said Darrell Wong, one of the report’s authors. He is a manager of FPInnovations, the non-profit forestry research center at the University of B.C.
But Wong said more study must be done before sawmills should consider jettisoning misting systems. Misting systems have a secondary function of knocking wood dust out of the air. Wood dust suspended in the air was confirmed as the fuel source for the two explosions by WorksafeBC, the province’s chief workplace safety agency.
As part of the new study, hundreds of dust samples from 18 sawmills were analyzed, with some samples sent to Chilworth Technologies, an lab in Princeton, N.J. that determines how explosive substances are.