Four deaths and scores of traumatic burns and injuries have resulted from the fiery conflagrations at the north-central mills, which were processing trees so destroyed by the mountain pine beetle they were long dead before harvest.
The independent agency that looks after worker safety ordered Thursday that B.C.'s 300 or so mills immediately get a grip on any dust problems.
But until that happens, employees will be on edge, said a seven-year mill worker in Williams Lake.
"The accumulated dust all of a sudden starts to shake down, kind of like when you dump flour off the countertop ... and that is as volatile as gasoline," said Dean Colville, who worked in a Tolko Industries plant until moving into the union office last fall.
"There's a lot of fear out in our workplaces right now, wondering if we could be next."
WorkSafe BC has notified all mills they have fewer than two weeks to conduct a thorough inspection and implement an effective combustible dust control problem.
Follow-up inspections will be conducted by May 9 to evaluate whether there is sufficient compliance.
"The reason for sending out the directive order is directly linked to the second catastrophic explosion in Prince George," said Roberta Ellis, senior vice president of corporate services with WorkSafe B.C.
"We've heard from workers, we've heard from unions, we've heard from employers. There's a high level of nervousness and concern."
The Prince George RCMP also announced Thursday that police have determined the explosions is not criminal in nature.
Mill workers say in recent years, they've noticed an increased quantity of particles floating in the air.
Colville said he believes production of pine-beetle-killed wood in the B.C. Interior has sped up since about 2005, and the heavier reliance on dead trees has been in part aimed at mitigating the risks of forest fires.
When he began working as a utility rover in 2004, he estimated there was a 50-50 split of moister green wood and dry pine beetle wood being processed. Now, he said the later accounts for as much as 90 per cent.
"The wood is so dry, the dust is so fine, that I don't think anyone really knew the potentials for these serious, almost bomb-like situations," he said.
When the mill in Burns Lake blew up and burned down in mid-January, people in the industry questioned how such an incident could be possible, he said. But after Monday's blast at the Lakeland mill in Prince George, no one believes it can be a fluke.
"Until we can know for sure and get everyone on the same page on looking at how these happened and what we can do to prevent it ... that fear will be out there," he said.
Two years ago, a ball of fire blew apart a room in the mill where Colville worked when a spark in a fuse set dust alight.
"Thank God no one was in there," he said. "At that point we made a conscious decision, the company (did), to focus more on cleaning up that fine dust — more than we already were."
The WorkSafe BC order reminds every employer about flammable air contaminants and asks them to step up their current plans, Ellis said.
Non-compliance will carry consequences, she said.
"We have the ability to impose an administrative penalty, but we also have the ability in law to close the work site down or close machinery down," she said.
"We've been very clear that where we do not see compliance, we will be considering that."
Peter Lineen, CEO of the BC Forest Safety Council, said the explosions have shaken the entire industry.
He previously worked as the lead investigator on a massive Alberta sawmill fire set off by dust.
"It was my baptism into the severity of these incident ... and how devastating they can be. No one was killed in that incident, but it was a substantial loss of a very large operation."
Wood dust standards are set primarily by the National Fire Protection Association in the United States, he said.
Studies are underway looking at wood dust, he added, and their outcome could prompt dust standards to be upgraded.
"Most of the standards on dust in wood-processing facilities, I'm not sure that it has ever accounted for what's recently been happening with beetle-killed pine."
FPInnovations, which bills itself as the world's largest private, not-for-profit forest research institute, has also been asked by the industry and government to evaluate fire safety associated with the pine beetle wood.
Vinh Nguyen is still healing from first- and second-degree burns to his face and hand suffered while working as a watchman security officer at Babine Forest Products when it burned down in Burns Lake, about three hours west of the Prince George plant.
He said mill workers' routine cleaning procedure often involved using a compressed air hose to blow dust off machinery, but that would simply blow dust into the basement. Another specialized team would come in next and suck up those particles, he said.
"Years ago, when I started working, you could see all the way across the floor, hardly any dust. But now, it's like a fog," he said.
"If a person hadn't been in an atmosphere like that before, they would cough."
He welcomed any measures that might clear the "heavier" air.
"The workers almost experienced the same incident as we did in Babine," he said. "They're feeling probably the same stuff as us — anger, frustration, depressed — and my prayers especially go out to them."