The cannabis industry is growing at a rapid rate. According to a report published by Marijuana Business Daily, the emerging sector is forecasted to overtake craft beer and organic food products. With legalization gaining momentum, it could reach $44 billion by 2020. The study also pointed out that for every dollar spent on weed, the local economy gains three dollars.
A recent trend in marijuana production involves cannabis extracts in the form of oils, shatter and wax. The concentrated forms of the plant offer potent levels of delta-9-tetrahydrocannabinol (THC), or the psychoactive compound in weed that is responsible for head-heavy highs commonly associated with Indica strains. In order to create such variants, growers rely on a special extraction process using butane, an extremely flammable gas. To reduce the risk of explosions, cannabis businesses that manufacture solvent-processed extracts must adhere to rulings on closed-loop extraction systems (WAC 314-55-104).
Using Butane for THC Extraction
Butane is an essential component to the THC extraction process. Extracts, like butane hash oil, are made by placing marijuana in a container, and pushing butane through the vessel. Ideally, the system should allow butane to escape seamlessly, and plant matter should stay inside the pod. During extraction, butane removes cannabinoids from marijuana. The mixture that escapes is evaporated, ensuring that butane does not end up in the final product. It is recommended to evaporate as much of the butane as possible for health reasons. Medicinal extracts are usually smoked by patients that require above average doses of cannabis, and thorough extraction may prevent the substance from ending up in the user’s lungs.
“You’ll need to keep extra gaskets in stock, as they’re known to wear out within a few weeks. Once they start wearing out you can have leaks, so it’s very important for you to switch these out on a regular basis. You’ll also want equipment to measure the butane in the air around us and inside our equipment to avoid build-up. It’s important to have simple tools like this to avoid lethal mistakes,” explained Daniel de Sailles, founder of Top Shelf Extracts.
Butane Explosive Properties
With an auto-ignition temperature of 405 degrees Celsius, butane is a flammable risk. Should the gas come in contact with a surface that exceeds its threshold, it will spontaneously ignite, causing fires and explosions inside the extraction facility. When it comes to weight, butane is 60.1 percent heavier than water with a liquid to vapor ratio of 288:1. Ignition of butane vapor (when an ignition source is present) may occur when mixed into the air at concentrations ranging between 1.86 - 8.41 percent. To prevent combustible reactions, some extract manufacturers work outdoors, apply proper ventilation practices and/or use fans to promote air circulation. For indoor facilities, it is best practice to install exhausts from the bottom of the lab at floor level using an explosion proof fan and venting into the air above roof level. Bulk storage should also be placed outside of the extraction lab.
C1D1 Lights for Extraction Labs
One of the main concerns when working with butane are ignition sources. Because it gas, it can easily leak into electrical systems, devices, outlets and switches. Due to the explosive nature of butane and the amount required during extraction, explosion proof lights must be applied in the facility. Such units can help reduce the risk of ignition or combustion.
It is important to consider that the term “explosion proof” refers to the fixture’s ability to isolate electrical sparks and ignition within the light, where it cannot spread or react with external explosive elements. The National Electric Code (NEC) provides details on the types of lights that can be used, depending on the combustible gases, vapors, dust, liquids or flyings present in the respective hazardous location. When addressing explosive gases (like butane) in a THC extraction facility, lights with Class 1 Division 1 (C1D1) approval ratings must be used.
Article 501 in the NEC sets forth the following recommendations for C1D1 lights:
• (1) In which ignitable concentrations of flammable gases, flammable liquid–produced vapors, or combustible liquid–produced vapors can exist under normal operating conditions, or
• (2) In which ignitable concentrations of such flammable gases, flammable liquid–produced vapors, or combustible liquids above their flash points may exist frequently because of repair or maintenance operations or because of leakage, or
• (3) In which breakdown or faulty operation of equipment or processes might release ignitable concentrations of flammable gases, flammable liquid–produced vapors, or combustible liquid–produced vapors and might also cause simultaneous failure of electrical equipment in such a way as to directly cause the electrical equipment to become a source of ignition.
In particular, butane falls under Group D of the Class 1 category:
Flammable gas, flammable liquid–produced vapor, or combustible liquid–produced vapor mixed with air that may burn or explode, having either a maximum experimental safe gap (MESG) value greater than 0.75 mm or a minimum igniting current ratio (MIC ratio) greater than 0.80. [497:188.8.131.52.4]