Two men were sentenced Friday to three years of probation for their roles in a butane explosion last fall in Astoria that injured two people.

William "Chris" West, 41, and Jason Oei, 45, entered Alford pleas in Clatsop County Circuit Court to third-degree assault, a felony, and reckless endangerment, a misdemeanor. Under such pleas, a defendant doesn't admit guilt, but acknowledges prosecutors have enough evidence for a conviction.

Clatsop County District Attorney Joshua Marquis addresses the judge during a sentencing hearing Friday morning. The defendants, William West, left, and Jason Oei on the right, were sentenced to probation.

West and Oei were making butane hash oil for their business, Higher Level Concentrates, when the space filled with the flammable gas and exploded. At the time, the company was on a state-approved list to process marijuana for the medical market.

A construction worker, Jacob Magley, 34, was working in the building when the blast occurred. He spent a month in a Portland burn unit recovering from his injuries.

Magley is suing 11 businesses and three people for violations of workplace safety laws. He filed the suit in Multnomah County and is seeking $8.9 million in damages.

Magley listened in to Friday's court proceedings by phone and declined to give a statement.

Clatstop County District Attorney Josh Marquis said the case represents the first felony conviction tied to a legal cannabis extraction business.

But Marquis, who opposed Oregon's marijuana legalization efforts, said the case isn't about cannabis.

"This is really not a drug case; this is a case about recklessness and an industrial accident," he said after the sentencing.

Attorneys for the men didn't immediately respond to requests for comment.

Higher Level Concentrates operated during a transitional period for Oregon's marijuana program when the health authority oversaw cannabis processors. The business wasn't inspected by regulators. Those businesses have mostly transitioned to the Oregon Liquor Control Commission, which has stringent fire and safety requirements in place for those businesses.

Marquis said the two had what's known as a closed loop extraction system designed to keep butane from escaping into a room, but they abandoned it because it "had sort of fallen apart on them."

Instead, he said, they used a more primitive and dangerous approach called "open blasting," which allows the gas to fill a room.

He said investigators found hundreds of butane canisters, all of which were "crudely punctured," despite labels warning not to tamper with the containers, Marquis said.

They started pouring the butane into the system "and literally throwing (the cans) into the corner," Marquis said.

It doesn't take much to ignite a butane blast. Something as mundane as a light switch can set off the odorless gas.

The business was fined $5,300 for a series of workplace safety violations related to the explosion. Oregon OSHA cited it for failing to ventilate the building, failing to have an adequate electrical system and failing to obtain city permits.

-- Noelle Crombie

503-276-7184; @noellecrombie