A construction worker who spent a month in a Portland burn unit after being injured in a butane-fueled explosion in Astoria last fall has filed a lawsuit against the company that made the cannabis extract, the property owner and the company that sold the flammable gas used to make the product.

Jacob Magley, 34, of Portland 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 was working as a contractor in the building when it exploded. The suit claims the company making the extract failed to keep butane from filling the room. He says the facility lacked adequate ventilation and exit routes, automatic sprinklers and gas detectors among other safety features.

According to the suit, he was not given fire retardant clothing or other protective equipment and was not warned about the dangers posed by butane.

Magley claims that Jason Oei, one of those named in the suit, consumed cannabis oil in a technique called "dabbing" while William "Chris" West handled butane. Magley alleges Oei's dabbing caused the explosion, which rocked the building on Oct. 19. West, too, was injured in the blast.

Amy Margolis, a lawyer for the pair, declined to comment Monday.

Making hash oil using butane can be dangerous. For years, the activity was unregulated and underground, carried out by home producers who often misunderstand the risks. The gas, a cheap and flammable solvent, is used to extract tetrahydrocannabinol, or THC, from marijuana flowers and leaves.

It can quickly fill an enclosed space, where something as ordinary as a pilot light can ignite a fireball.

The dangers led to a new state law that makes unlicensed production of marijuana extracts a felony. The provision is intended to target homemade butane hash oil operations and not commercial operations, which are regulated by the state.

Clatsop County authorities launched a criminal investigation into the explosion. That inquiry is pending. An official with Oregon OSHA, an agency whose mission is worker safety and health, said Monday that its investigation also is ongoing.

Meanwhile, Oei and West are have applied for licenses to produce and process marijuana for the recreational market, said Mark Pettinger, a spokesman of the Oregon Liquor Control Commission.

Pettinger said the agency is not processing the application until outside agencies complete their investigations. The outcome of those investigations could factor into whether the state issues a license, he said.

Magley's lawyer, Jonah Flynn, of Atlanta, Georgia, said Monday that his client suffered burns on his upper torso and that emergency workers arrived to find his skin "falling off."

The episode has caused Magley lasting trauma, his lawyer said.

"He's having a hard time," he said.

Flynn said Astoria Trading Co. is the parent company of Higher Level Concentrates, which at the time of the blast was on the Oregon Health Authority's list of state-authorized marijuana processors.

Flynn, a personal injury lawyer, also represented a Gresham man severely burned in a 2013 butane hash oil blast that killed his friend. That suit has been "resolved" and dismissed, Flynn said, adding that the terms of the resolution are confidential.

-- Noelle Crombie

503-276-7184; @noellecrombie