By Bob Young

The Seattle Times

SEATTLE — From Spokane to Seattle, Vancouver to Mount Vernon, amateur chemists have caused explosions in recent months, often in homes, while using flammable solvents to produce hash oil.

The most recent blast occurred Monday in a Spokane Valley kitchen. Three weeks earlier, an explosion in a Vancouver home left a man hospitalized with burns to his face.

Last month, hash-related explosions caused $100,000 in damage to a Kirkland, Wash., apartment and lifted a South Seattle house off its foundation.

The most devastating local explosion may be a November blast in Bellevue, Wash., that did more than $1 million in damage to the Hampton Greens apartment building. In escaping the fire, former Bellevue Mayor Nan Campbell, 87, fell and suffered injuries that contributed to her death in the hospital two weeks later.

Bellevue police said they are investigating the fire and have declined to release a cause. A source close to the case said investigators found all the supplies to manufacture a marijuana-related oil — possibly hash oil — inside one of the burned apartments.

This phenomenon is not part of the state’s legal marijuana system. Under rules for the state’s new industry, hash oil can only be made in licensed facilities — and those do not include homes.

State rules also require that only certain equipment and chemicals be used for safety reasons. No facilities have yet been licensed by the state, which is sifting through 7,000 applications for marijuana businesses.

Still, amateur hash oil production and the resulting explosions likely will continue, as the Internet is rife with tutorials and the popularity of the super-potent hash oil is increasing with young users.

In its Weed Issue last year, Rolling Stone called hash oil “America’s insanely baked future.” Mark Kleiman, author of “Marijuana Legalization,” has predicted that concentrated extracts will eventually eclipse traditional marijuana in the state’s new recreational pot industry.

Explosions are not limited to Washington state. A search of news reports last year turns up stories of hash oil explosions from Florida to Hawaii, with a rash along the West Coast.

The Oregonian reported a Jan. 10 blast in Forest Grove that left a man in critical condition. In the past 14 months, at least 17 people have landed in Southern California burn centers due to hash oil accidents, according to the Los Angeles Times.

Another 27 victims were treated by a burn unit in Northern California, the paper reported, noting that the hash oil toll was far worse than injuries attributed to meth lab explosions in the same period.

The Federal Emergency Management Agency sent out an alert last year noting that many explosions were misidentified as meth lab mishaps.

People have consumed concentrated forms of marijuana for several thousand years. The most common form has been hashish, generally made by removing the most psychoactive resin from pot plants and compressing it into slab form.

Several years ago hash oil — in forms called honey oil, budder, shatter and wax — exploded in popularity.

Hash oil can be extremely potent. Marijuana in Seattle medical dispensaries tends to contain 12 to 20 percent THC, pot’s key psychoactive chemical. Modern hash oil tends to have 40 to 70 percent THC.

“We’ve seen purities as high as 73 percent,” said Jodie Underwood, spokeswoman for the federal Drug Enforcement Administration.

The drug’s use has soared with the rise of vaporizing devices, such as “vape pens,” sleek cylindrical gizmos that look like e-cigarettes. Vaporizers are used to consume “dabs” of hash oil in a way that lacks the telltale odor of burned marijuana flowers and is more discreet than sparking a joint or blazing a pipe.