NFPA Journal - September/October 2016 - 49

COVER STORY MARIJUANA INDUSTRY SAFETY Extraction Action In addition to growing, the other principal activity of the pot industry is extraction, where THC, the primary psychoactive ingredient in cannabis, is separated from the plant and processed into a gummy substance known as hash oil. The material can be more than 80 percent pure THC-more than four times the potency of regular marijuana-and can be smoked or used in candy, drinks, and other pot products. Extraction is done with specially made equipment that uses butane or propane, and can be fraught with potential hazards if not conducted properly. Here's how it works:  A worker at The Clinic, a marijuana production facility in Denver, loads marijuana into the extraction column of an extractor machine.  The extraction column is connected to the collection vessel. A lid is placed over the column and connected via hoses to the solvent tank.  Liquid butane is pumped from the tank on the lower right to the top of the extraction column. The butane passes through the marijuana in the column, extracting the THC, and the mixture collects in the vessel at bottom left. Most of the remaining solvent is then returned into the original tank, leaving the THC concentrate.  The THC concentrate is scooped from the collection vessel into a glass dish. At this point the concentrate is the consistency of cake batter due to residual butane.  The concentrate is spread out on metal trays and is then placed in a vacuum oven specifically designed for marijuana extraction.  The concentrate cooks under low heat for about five days, until the remaining butane has evaporated out. Numerous variables during baking can create a variety of different products.  Workers divide and package the finished concentrate into 1-gram doses for sale at one of The Clinic's stores. first commercial grow operation during a general inspection in 2009, and within months found about 150 more-enterprises that, in the absence of permitting and licensing rules, nobody knew about. Many growers had rented warehouse, manufacturing, or office space, setting up shop in anonymity. A significant number of the grows, the fire marshal's office soon discovered, were a jumbled mess of wires, hoses, extension cords, plastic tarp dividers, and non-compliant locks and interior finishes. "Without exaggeration, we just stood there and thought, 'Where do we even start?'" Lowrey told me. "What we saw in those facilities scared us to death." Denver, which has by far the most marijuana facilities in the state, also had a surge of shoddy, under-theradar grow operations pop up in 2010, overwhelming the department's inspection group. Exacerbating the problem, many marijuana growers refused to address code violations, Jeff Fletcher, a lieutenant in charge of marijuana inspections in the Denver Fire Department, told me. As a result, marijuana-related summons and court appearances monopolized fire inspectors' time. Powerful hot lights hanging close to plastic room dividers, along with overloaded electrical circuits, led to a number of fires at the time, Lukus said. There were other problems, too. Many grow operations were using elevated levels of CO2 to increase plant growth, and toxic chemicals to fumigate grow rooms "without alarms, signs, or permits, and without respect to the neighbors next door," Lukus said. Many grow facilities had non-compliant locks or bars over the doors and windows to keep burglars out-barriers that could also prevent egress in a fire, and also keep firefighters from getting in. By 2010, commercial production of marijuana concentrate had also emerged. The production process typically involves using liquid butane or propane as a solvent to extract THC, marijuana's main psychoactive ingredient, from the plant. Butane is blasted through a cylinder packed with marijuana; the goo that drips from the opposite end is heated in a vacuum oven to remove the excess butane, leaving behind a sticky amber substance often called hash oil, which can be more than 80 percent pure THC-four times more potent than the average pot plant. It can be smoked or used to make a host of marijuana infused products, or MIPs, such as candy, drinks, and cookies. The term "MIP" has also become common parlance for an extraction facility. Beginning in 2009, home explosions involving hash oil production were occurring all over Colorado. When commercial production began not long after, the safety precau- SEPTEMBER/OCTOBER 2016 NFPA JOURNAL 49

Table of Contents for the Digital Edition of NFPA Journal - September/October 2016