Driven by deregulation and acceptance, the legalization of cannabis for medical and recreational use is rapidly becoming part of the modern, industrial world. With the increase in demand, new construction and old warehouses are being re-purposed to house new controlled environment grow and extraction facilities. With this increased facility development comes the increased concern for worker safety. There has been a similar increase in the number of worker accidents within the industry. To better protect workers, Local Building and Fire Code officials are now starting to require additional permits, including Life Safety requirements.
Some facilities may consist of both a grow facility and an extraction facility. These facilities will be required to meet additional requirements.
Current cultivation methods of cannabis and industrial hemp utilize Carbon Dioxide (CO2) enrichment to increase plant growth and development. CO2 is classified as an asphyxiant gas, meaning it has the potential to reduce or displace normal Oxygen concentrations in the air.
- CO2 can be stored in vacuum-jacketed cryogenic liquid cylinders, or in steel or aluminum cylinders as liquefied compressed gas.
- It can also be produced onsite by Carbon Dioxide generators. If CO2 is generated using fossil fuel combustion, Carbon Monoxide (CO) and Nitrogen Dioxide (NO2) can be produced. Both CO and NO2 are toxic gases that can cause significant health effects or even death for exposed individuals.
The two categories regarding gas detection include explosion/fire fueled by combustible gases and asphyxiation due to Oxygen (O2) displacement from Carbon Dioxide (CO2) leaks. The choices involving the source of CO2 can have an impact on what is needed to design a Life Safety System properly.
If the release of a hazardous or combustible gas can cause immediate harm to a person or property, a means to mitigate the gas should be provided. Combustible liquids and compressed gases used in
extraction or processing in these facilities should be vented in accordance with International Fire and Mechanical Codes. Utilizing a gas detection system can activate an exhaust system and shut down the extraction process to prevent a dangerous event.
CBD Concentrate is produced by extracting cannabinoids from the cannabis plant. Solvent-Based Concentrate is the most common, and the process involves passing gas through a solvent extraction device filled with cannabis plant matter.
- Commonly used combustible gas solvents include Butane (C4H10), Propane (C3H8), Hexane (C6H14), and Ethanol (C2H6O).
- Hypercritical (Carbon Dioxide) CO2 is another solvent rising in popularity, which adds the risk of asphyxiation to the extraction process.
Macurco Gas Detection equipment will detect gas, provide visual and audible alarms, and can control appliances to mitigate the gas before reaching hazardous levels. Commonly controlled equipment includes ventilation systems and mechanical interlocks that shut down the flow of gas to the unit when gas is detected. Additional audible and visual alarms can also be controlled to alert occupants of unsafe levels.
The 2018 edition of the NFPA Fire Code will likely have a chapter on fire safety for the cannabis industry. Regulation and enforcement of handling hazardous gases may vary by state, so be sure to consult your Fire Marshall or AHJ for local requirements.
Typically grow rooms are not electrically classified and general-purpose equipment works great for monitoring Carbon Dioxide levels. The graphic to the right displays the control panel outside the room showing gas values and controls the ventilation and alarm notifications both internally and externally. The system is designed to engage the exhaust system if CO2 levels are slightly elevated followed by engaging the alarms if CO2 levels are approaching dangerous levels.
Typically extraction rooms are rated either Class 1 Division 1 or Class 1 Division 2 depending on the process and room setup. If your local jurisdiction does not have this requirement it is highly recommended due to the increased risk of combustible gas that is continuously present in the room and used in the process of production. The following graphic depicts a Class 1 Division 1 room with a C1.D1 gas detector, horn, and strobe and then general-purpose equipment outside the room.
The system is designed to engage multiple alarm setpoints if the presence of combustible gas hits predetermined levels of a low, medium, and high %LEL. The highest setup should still be significantly
lower than the explosive level for the particular gas of concern (typically the following values are a great reference for multiple set points 10% LEL Low Alarm, 20% LEL Medium Alarm, and 30% LEL for High Alarm).
DVP-120 Control Panel Family
The Macurco controller family has a variety of options to meet the needs of your facility. These controllers in conjunction with Macurco gas detectors provide automatic control to help maintain an acceptable environment in parking garages or other applications. These systems are easily configured making installation hassle-free.
Industrial Gas Detectors
Macurco’s TracXP products are suitable for CO2 monitoring in Grow facilities requiring a higher degree of environmental protection in spray irrigated or washdown areas. TracXP also includes combustible gas (LEL) detectors which are rated for Class I, Div. 1, and Div. 2 hazardous locations such as extraction areas. These units are available in fixed or wireless versions.