Hazards of the Trade
As with any industrial process, marijuana production comes with an assortment of hazards, some more exotic than others.
In general, the hazards break down into those associated with growing, and those associated with the THC extraction process. Growing hazards include:
Egress—With space at a premium, most grows are very crowded, with plants being moved often according to their grow cycles. Keeping egress paths and exit doors clear can be a problem. Also, since almost all grows are located in retrofitted buildings, “a lot of them go on and on—it’s maze-like, you’re going through doors and doors and more doors,” said Brian Lukus, a fire protection engineer who has led the Denver Fire Department’s marijuana efforts. “It meets egress requirements, but during a fire it would be easy for a firefighter to get lost.”
Lights—Grows have a lot of hot, dangling lights, many of which remain on 24 hours per day. If lamps are located too close to combustible materials, fires can occur. Some grows use twine to hang lights, leading to worries they could crash down on responders in a fire. Denver has started requiring that lights be hung on chains.
Plastic dividers/combustible interior finishes—Grows need many separate rooms to segregate plants by growing and light cycles. Some growers erect tents inside of rooms, or cordon off spaces with tarps or other flammable materials, creating fire hazards and egress issues.
High Electrical Loads—Hundreds of high-powered lights, air conditioning, fans, and other systems mean grow houses use a significant amount of electrical energy. If grows are not compliant with the NEC®, overloaded circuits and wiring can spark fires.
Fumigation—Molds, mildews, and fungus can destroy a crop and result in millions of dollars in losses. Some grows have adopted fumigation measures using sulfur dioxide, which can be toxic to employees and first responders.
Illegal locks/barriers—The valuable commodity inside has prompted some grow owners to tighten security by placing bars on doors and windows, using non-compliant locks, and even guard dogs, all of which can hinder egress and ingress in a fire or other emergency.
Carbon dioxide (CO2) enrichment—Many growers claim CO2-enriched environments can increase pot yields by 20 percent. While ideal growing CO2 levels remain well below what can asphyxiate a person, failures and leaks have occurred. In most jurisdictions, rooms are required to be monitored and alarmed with automatic shut-off valves in case of a leak.
The extraction process uses a solvent like butane or propane to collect and concentrate THC, the primary psychoactive ingredient in marijuana. Extraction hazards include:
Butane/Propane—The most popular extraction process involves use of these flammable and potentially explosive substances as the solvent to separate THC from the plant. Although extractors must have a closed-loop system design, off-gassing does occur when the collection cylinder is opened and hash oil is scooped out.
CO2 extraction—This type of THC extraction doesn’t require flammable substances, but the machines operate at pressures as high as 10,000 pounds per square inch. If not installed or designed correctly, extractors can explode, causing destruction and death.
Regulation/oversight—In the absence of a stand-alone code, some enforcers and regulators are unclear on, or differ in their opinions on, the code requirements for extraction facilities. Some jurisdictions have yet to adopt any local codes regarding these facilities.
Extraction Equipment—There are no listed or performance-based standards for extraction equipment. Engineers can disagree on safety requirements and will sometimes use different codes as a basis for equipment review.
insufficient training—Extraction operators are not required to be trained, nor are there any accredited certification programs for marijuana extraction operation. Consistency is lacking.