DENVER — A potentially explosive technique used to make a powerful marijuana concentrate from pot leaves and stems has federal investigators cautioning the public about the risks of hash oil extraction.
When done wrong, the process can cause a fireball or flash fire that blows out windows and doors. Authorities say they've seen an uptick in hash oil-related incidents from California to Washington and New Jersey, and say it's in part because people learn the basic technique over the Internet but often lack the sophistication to do it safely.
While the technique to make hash oil — also known as wax, shatter, butter or dabs — isn't new, Bureau of Alcohol, Tobacco, Firearms and Explosives experts say the danger can be greater in states that have legalized marijuana because people have access to larger quantities of marijuana plants. ATF agents aren't taking a position on marijuana legalization but are asking lawmakers to consider the ramifications of permitting hash oil extraction.
"I don't think they realize it's unsafe," said Billy Magalassi, chief of the ATF's fire investigation and arson enforcement division. "Kids are curious but they're dealing with things that are very dangerous."
Colorado's constitution permits residents to make marijuana extracts like hash oil, although Gov. John Hickenlooper is considering whether to sign a proposal specifically banning the use of butane for hash extraction.
Users make hash oil by running butane or another solvent through a tube filled with dried marijuana clippings, left over after the flowers have been cut off for smoking. The solvent strips the THC, or psychoactive compound, out of the plants, leaving behind an oily liquid that can be further solidified by heating the mixture to evaporate the butane. Because it's heavier than air, the butane sinks to ground level, where it can be ignited by a stove's pilot light or a refrigerator's compressor motor. People making hash oil also sometimes store it in their refrigerator, where the butane continues to evaporate.
Users like hash oil because it allows them to extract marijuana from otherwise unusable trimmings. In states where marijuana is illegal, black-market dealers generally sell only the flowers. But in Colorado and Washington, where recreational marijuana is grown and sold openly, users can easily and cheaply acquire the trimmings. The extract is far more potent than marijuana "bud," and more easily transported.
Last year, Colorado had 32 confirmed hash oil extraction explosions and 30 injuries, up from 12 explosions and 18 injuries in 2013, said Kevin Wong, an analyst with the federally funded Rocky Mountain High Intensity Drug Area task force. In 2015, only two explosions have been confirmed through mid-May.
Wong said the drop in reported Colorado explosions is likely due to a combination of factors, including users being more careful or switching to a different solvent, such as hexane, propane or carbon dioxide. Publicity about the danger also helped, he said.
"I feel the coverage has really helped to educate the public, to spread the word, to publicize the dangers," Wong said. "Does it mean they've stopped doing it? No. Does it mean they've gotten smarter about how they report it? Yes. (And) they're finding other chemicals to use in place of butane."
Colorado prosecutors have frequently brought charges against users who cause explosions while making hash oil, but also usually end up dropping them. That's because the amendment that legalized marijuana use and possession also guaranteed residents the right to make extracts.
Denver marijuana advocate and attorney Rob Corry says some of the fears are overblown. Corry has represented hash oil manufacturers facing arson charges following explosions. He said cops and prosecutors are wrongly targeting a small number of hash oil extractors who make mistakes not significantly different than those of a bad cook.
"If you fry a turkey indoors, that's very dangerous. That can cause a major problem. It doesn't mean you've committed a felony offense though," Corry said.
Contributing: KUSA-TV, Denver