Worker emptying cannabis buds into oil extraction machines

Question: The legal cannabis production industry has arrived in my state, and we are running into CBD oil extraction machines constructed with motors and other components that are not Certified (Listed). 

Is there a UL Standard for plant oil extraction equipment, and does UL certify (list) this type of equipment?

Answer:  Yes, UL certifies oil extraction machines. Underwriters Laboratories recently published ANSI/CAN/UL/ULC 1389, the Standard for Safety for Plant Oil Extraction Equipment for Installation and Use in Ordinary (Unclassified) Locations and Hazardous (Classified) Locations. UL/ULC 1389 is a bi-national Standard for the U.S. and Canada covering commercial and industrial plant oil extraction equipment for installation and use indoors in ordinary (unclassified) locations and hazardous (classified) locations.

UL develops safety standard for plant oil extraction machines and systems

UL/ULC 1389 addresses fire, electric shock, injury to persons and explosion risks associated with extraction equipment installed in processing facilities. The Standard covers:

  • Preparatory equipment used for trimming, deseeding, drying/curing or other activities to prepare plant material for extraction
  • Extractors involving flammable or nonflammable materials
  • Extraction booths, including modified freestanding shipping containers or pods, used to enclose or protect plant oil extraction equipment
  • Post-processing equipment
  • Plant oil utilization equipment that utilizes plant oil subsequent to the overall extraction process such as dispensing machines and assembling machines

While there are a number of techniques to extract plant oil, one common method uses flammable or combustible materials, including hydrocarbons such as butane, liquefied petroleum gas (LPG), pentane and propane, and alcohols such as ethanol. Other methods involve using carbon dioxide or heat with a mechanical press to literally squeeze the oil out of the plant.

The most significant hazards from the extraction process are associated with the use of hydrocarbons and alcohols. Hydrocarbon and alcohol extraction present major safety hazards as the processes call for using flammable solvents in an extraction process that is rarely automated. This means that a worker is almost always working in close proximity to these flammable solvents. However, even with its high volatility, hydrocarbon extraction is primarily used by large-scale operations due to the speed and efficiency of the method. With mechanical presses, pinch points and burns are always a possibility; operators need to take steps to mitigate limb amputations. For CO2, asphyxiation is a concern as carbon dioxide is a colorless and odorless gas. It can be deadly even when normal oxygen levels are present.

Creating a safer working environment for plant oil extraction machines and processing facilities

Based on the application, equipment installation is in accordance with the manufacturer’s instructions, together with the relevant U.S. and Canadian codes and standards.

For the U.S., the following are applicable:

  • NFPA 70, National Electrical Code® (NEC®)
  • International Fire Code® (IFC®)
  • NFPA 1, Fire Code®
  • NFPA 55, Compressed Gases and Cryogenic Fluids Code®
  • NFPA 58, Liquefied Petroleum Gas Code®

For Canada, the following are applicable:

  • CSA C22.1, Canadian Electrical Code, Part 1® (CE Code®)
  • ULC-S4400, Premises, Buildings and Equipment Utilized for the Cultivation, Processing and Production of Cannabis®
  • National Fire Code of Canada® (NFC®)
  • CSA B149.1, Natural Gas and Propane Installation Code®

UL certification services for plant oil extraction machines and systems

UL presently Certifies (Lists) equipment for the legal cannabis industry in the U.S. and Canada across 40 product categories for ordinary (unclassified) locations and hazardous (classified) locations, including:

You can find guide information and UL Certifications (Listings) for these product categories on UL Product iQ™ at Just enter the appropriate 4- or 5-character category code listed above at the Product iQ search field. For a list of all product categories used for UL Certifications (Listings) for the legal cannabis industry, enter “cannabis” at the Product iQ search field.

For equipment already installed in the field that is either not UL Certified (Listed) or that is UL Certified (Listed) but that has been modified, UL can field evaluate the equipment. For more information on UL field evaluations or to obtain a quote, please contact UL’s Customer Service at 877-854-3577, #2, or  For information on testing services for the legal cannabis and cannabidiol (CBD) industry click here.

Reprinted with Permission from IAEI News, UL Question Corner May/June 2020.