Cannabis grow facilities are commonly referred to as “laboratories” housing nurseries or hydroponic operations to grow cannabis plants. These facilities operate in virtually every state — from large urban areas to small rural communities — and range in size from a few plants in a one-room basement to a warehouse with 10,000+ plants.
Grow operations — both lawful and not — are likely to continue spreading as global cannabis sales trend upward year-by-year. According to BDSA, a Denver-based research firm with expertise in the cannabinoid market, global cannabis sales reached more than $35 billion in 2022, a 22% increase from the previous year. By 2026, global sales are forecasted to surpass $61 billion.
As grow operations become more ubiquitous, it is critical to understand the wide-ranging risks that cannabis production poses to operators and the public.
Grow facility equipment
Growing cannabis indoors requires artificial lighting, air conditioning and dehumidification —which all mimic elements of the outdoors while allowing control of environmental parameters — in addition to water, electricity and other utilities. Other necessary equipment includes racking stations, trimming tables, grow lights and systems, fans, drying equipment, temperature/humidity controls, vertical racking, packing necessities and high-density storage systems.
Extraction is the conversion of target molecules in cannabis to a usable form. It removes the oil from the plant and collects its potent compounds: tetrahydrocannabinol (THC), the main psychoactive compound that produces the high sensation, cannabidiol (CBD), which cannot cause a high by itself, and terpenes, compounds that shape distinctive aromas and are integral to creating vaping oils, lotions, foods, etc.
Hydrocarbon extraction, or butane hash oil (BHO) extraction, is one of the most popular and effective solvent-based methods, with relatively low operating costs. It is also riddled with risk due to its use of butane, a highly flammable hydrocarbon found in crude oil, natural gas and coal, used by extractors for its purity and low boiling point. The BHO extraction process first involves fractional distillation, which separates the components of crude oil and compresses the butane into an odorless, highly flammable liquid. The liquid butane is then used to wash over the cannabis plant material, dissolving the cannabinoids and terpenes. This results in a viscous, cannabis-infused oil. While effective, BHO extraction can be extremely dangerous if not done properly, as butane is prone to explosion.
Butane is extracted either by closed-loop extraction (performed at professional facilities), which removes the possibility of gas leaks by containing all flammable solvents within commercial-grade extraction equipment, or the far more dangerous open-loop extraction. During open-loop extractions, raw cannabis material and butane is placed inside a metal/glass tube to separate the cannabinoids from the plant material. The butane is then released into the atmosphere. A single spark or flame can easily cause a deadly explosion. Most unlawful operations resort to the latter method.
Diane Spinner, an EFI Global veteran fire services expert, has investigated several honey oil butane explosions, all within apartment buildings. In one scenario, the next-door-neighbor was unaware of the activity yet found herself engulfed in an explosion.
Robert Rullan, a senior fire investigator at EFI Global, responded to a separate incident involving a single-family residence. On site, he observed leafy material flowing down the driveway as the garage was doused with water. A firefighter was transported to the hospital after suffering an electric shock. Rullan’s investigation later revealed that the tenant had incorrectly wired the electric panel and bypassed the meter to steal electricity.
During another occurrence, investigators discovered an operation after a fire spread through an industrial building. Large amounts of butane, and extension cords strung everywhere, were found inside. If the butane had been on fire minutes longer, a major explosion would’ve occurred, damaging surrounding property.
Loss considerations and common hazards
Many over-indulgent growers replace household circuit breakers once they repeatedly trip, with a higher rated ones. But if too many electrical devices are connected to a circuit, and their current draw exceeds the breaker’s rating, the breaker is supposed to trip for your safety. Electrical wiring issues are problematic too, such as splicing too many electrical conductors together or twisting and taping connections instead of using wire nuts.
High-power, high-intensity discharge (HID) lighting used by cannabis grow operations presents a hazard when combustible materials encounter the hot glass lamp, resulting in glass breaking and hot debris spreading. Fluorescent lighting can be hazardous if incorrectly wired, cheap, defective, or it contains failure-prone ballasts or power supplies.
Many facilities fail to follow national electrical code (NEC) requirements. Some operators even avoid paying bills altogether by bypassing the electric meter. In addition to being illegal, this practice exposes the operator to lethal shock and potential fire hazards.
Improper installation methods, inadequate housekeeping, the use of non-Underwriters Laboratories (UL)-certified equipment, and lack of appropriate maintenance all increase risks of poor connections and eventual fires — even in legally run facilities. Losses can be prevented by conducting a risk assessment with technical experts who can identify the hazards and provide risk mitigation options.