Cannabis industry hazards occur in many forms and must be effectively identified and managed to ensure employee health and safety. Recent publications indicate that cannabis industry hazards are more numerous and varied than many might have expected.

Cannabis is now legal in some form (medical and/or recreational), but the industry has yet to develop as a full-fledged, law-abiding entity operating under the same occupational health and safety considerations and other regulatory compliance mandates as those expected to be adhered to by businesses in more well-established industries.

In the cannabis industry, there is quite often little to no concern given to proper training for employees regarding hazards inherent to the industry.


Recognizing Cannabis Industry Hazards

To address the need to identify and meaningfully appreciate the significance of cannabis industry hazards, the Colorado Department of Public Health and Environment assembled a committee of subject matter experts.

This committee called the Colorado Cannabis Occupational Health and Safety Work Group, comprises epidemiologists, medical doctors, industrial hygienists, safety professionals, and regulatory specialists.

Together these individuals worked to create a publication designed to help cannabis industry employers understand the hazards inherent to industry operations and, ultimately, to construct viable occupational health and safety programs to protect their employees.

Published in January 2017, the resulting Guide to Worker Safety and Health in the Cannabis Industry is perhaps the most comprehensive document released to date on the topic. It should be noted, however, that the guide is not intended to cover all pertinent occupational health and safety regulations, nor does it include new legislation enacted specifically for the cannabis industry.

These efforts reflect a work in progress; the Colorado Cannabis Occupational Health and Safety Work Group explicitly state that it intends to continue to meet and improve the information in the guide.


Breaking Down Cannabis Industry Hazards

Many of the hazards that can be found in the cannabis industry are the same as those known to be present in workplaces throughout many industries.

It is therefore important to understand that, while the particulars may be unique, drawing attention to what differs about the cannabis industry is not the goal of articles such as this; rather, the purpose is to reveal and explore the commonalities.

These hazards are hazards just like those in any other industry and, as such, must be appropriately identified and managed. Cannabis industry hazards can be broken down into three (3) main categories: biological, chemical, and physical.

The following sections will present some of the most common sources of hazards in the cannabis industry separated into these three categories.


Biological Cannabis Industry Hazards

Biological hazards are associated with direct contact with cannabis plants. Bacteria and fungi can cause respiratory issues, eye, skin, and throat irritation, nasal congestion, and other adverse health effects.


Employees who cultivate and/or trim cannabis may be susceptible to mold exposure. This is due in large part to the high humidity levels required for cannabis production – sometimes as high as 70 percent. This can lead to mold growth, and mold spores in the air can cause wheezing, coughing, trouble breathing, respiratory infections, and exacerbation of asthmatic conditions.

It may be necessary to enlist the services of an industrial hygienist to perform air monitoring to assess mold spore levels in the areas where employees will be working. If necessary, workers may have to wear Personal Protective Equipment (or PPE).

Controlling moisture is extremely important in limiting mold growth. Standing water contributes to humidity levels, so proper irrigation can help limit accumulation. Engineering controls such as increasing ventilation or switching from sweeping to vacuuming for the cleanup can also help to combat mold exposure.


Itchy skin, hives, and swollen, irritated eyes can result from direct contact with cannabis plants. Some individuals are allergic or hypersensitive to the plant, and reactions can worsen with repeated exposures. If eliminating exposure is not possible, then the ventilation, job rotation, and PPE can be helpful alternatives.

Chemical Cannabis Industry Hazards

Chemicals present numerous health and safety hazards throughout virtually every profession, so it should be of no surprise to find many such instances in the cannabis industry.

To keep employees safe in the workplace, information about any potentially harmful substances must be provided to workers in a way that can be easily accessed and understood. The most common methods of achieving this are through training and by making chemical product information, usually via Safety Data Sheets (SDSs), readily available to employees.

Carbon Dioxide

For cannabis industry employees who work in cultivation, carbon dioxide (or CO2) may be encountered. CO2 is used in liquid gas or dry ice form to increase plant growth and during the extraction process to produce concentrates (CO2 as compressed gas stored in a cylinder may also present a physical hazard).

CO2 is a simple asphyxiant, meaning that it can displace oxygen at high concentrations. CO2 exposure can cause symptoms such as headache, dizziness, rapid breathing, and increased heart rate; in extreme cases, unconsciousness and death can result. This is why facilities that manage CO2 commonly have monitoring devices.

Cannabis industry employers must be aware of the health and safety hazards presented by CO2 and the importance of installing monitors and keeping them properly maintained and calibrated. Dry ice should never be used in small and/or confined spaces and should be handled with proper PPE, such as gloves and safety glasses.

It is also necessary to train employees on the effects CO2 can have on an individual’s health so that signs and symptoms of CO2 exposure can be effectively recognized.

Carbon Monoxide

Cannabis workers cultivating the plant may be exposed to carbon monoxide (or CO) in their operations, and any employees in areas where generators or other gasoline-powered equipment are being used (without adequate ventilation) may be at risk for elevated levels of exposure.

Other sources include water heaters, compressors, forklifts, floor buffers, and space heaters. CO is an odorless gas that interferes with the blood’s ability to carry oxygen throughout the body. The danger is that high concentrations of CO can overwhelm a person without warning, causing neurological damage, illness, coma, and even death.

As with CO2, CO monitors are a necessity when operating equipment that produces CO. A ventilation system that can remove CO from the work environment can be highly effective. Using alternatives to gasoline power whenever possible, such as equipment powered by electricity or compressed air, can eliminate sources of exposure.

As with all matters of employee health and safety, it is important to provide cannabis industry employees with training covering the causes and symptoms of CO poisoning.

Indoor Air Quality

All employees working indoors are affected by a poor indoor air quality environment. Cannabis cultivation produces ozone from the chemical reaction of nitrogen oxides and volatile organic compounds, such as terpenes that are given off from the cannabis plant.

According to the Guide, “Terpenes and nitric oxides are associated with eye, skin and mucous irritation. Ozone can cause decreased lung function and/or exacerbate pre-existing health effects, especially in workers with asthma or other respiratory complications. More research is needed to characterize potential exposures to ozone, nitrogen oxides, and volatile organic compounds in cannabis cultivation operations.”

The key, as mentioned above, is proper ventilation. It is recommended that HVAC systems be of the proper size and adequately maintained. PPE in the form of respiratory protection may still be needed in certain places, so it is important to know the areas of concern.


Facilities that grow cannabis commonly use insecticides and fungicides, and some pesticides carry certain skin and respiratory hazards. Anyone who cultivates or harvests cannabis, mixes, loads, or applies pesticides/fungicides, or cleans or repairs equipment used in the process of applying pesticides/fungicides is affected.

The Environmental Protection Agency (or EPA) Agricultural Worker Protection Standard, sets forth certain requirements intended to reduce the risk of employee poisoning from pesticides. Employees applying pesticides/fungicides must not do so without being aware of the associated toxicity specifications listed on the manufacturer’s label; if necessary, proper PPE should be worn to protect against exposure.

This can be aided by keeping on hand the relevant Safety Data Sheets (SDSs). Additionally, containers holding pesticides/fungicides should be labeled with the name of the product, the active ingredient, the EPA registration number, and all applicable human hazard signal words.

Disinfectants and Other Cleaning Chemicals

While these hazards may seem to be common knowledge, employees must be warned of the potential hazards of all cleaning agents used at the workplace – even common household cleaners. When even basic cleaning agents are used regularly they can cause skin irritation or respiratory issues. Injuries due to spills and splashes can also occur.

Chemicals should be selected as appropriately as possible based on the specific microorganism(s) intended to be eliminated. Basic hazard communication (right-to-know) safety training should be conducted so that employees are aware of the hazards of the chemicals kept at their facility and basic facts such as never mixing bleach with ammonia.

Safety Data Sheets (SDSs) should be kept and cleaning agents labeled appropriately.

Nutrients and Corrosive Chemicals

Employees who work cultivating cannabis plants and those who mix plant nutrients may encounter corrosive chemicals used for plant growth. These corrosives can be so potent that they can even damage or destroy metal.

The chemicals can irritate or burn the eyes and can present respiratory hazards if their vapors are inhaled, burning the inner lining of the nose, throat, and lungs. Most corrosives are either acids or bases – acids and bases should never be mixed.

Further considerations must also be noted concerning storage, such as making sure not to store acids on metal shelves or with water-reactive metals. Proper training should be provided, and PPE should be worn when handling corrosive chemicals. Employers must also provide areas to wash up and emergency eyewash stations.


Physical Cannabis Industry Hazards

Of all the hazard types, the cannabis industry shares more physical hazards in common with other industries than any other category of hazard.

Many of these hazards can be found in almost every workplace and while attention to the proper management of all physical hazards is always critical, the focus in this section will be on those hazards most specific to the cannabis industry.

Compressed Gas

As mentioned in the above description of CO2 hazards, compressed gas in highly pressurized cylinders can often be found at cannabis cultivation and extraction facilities. Compressed gas cylinders are hazardous because of this high pressure.

Most cylinders have safety-relief devices designed to prevent a rupture in the case of excessive pressure buildup, but a broken or leaking valve can be extremely dangerous. Cylinders exposed to fire or extreme heat are at risk for explosion.

Cylinders must be stored upright, properly chained, and kept at the appropriate temperature. When not in use, cylinder caps must be in place. Safety Data Sheets (SDSs) on the gases being used at the facility should be available, and employees must be properly trained.


Employees whose job duties involve trimming cannabis leaves or other cultivation tasks requiring awkward, repetitive postures, motions, and/or lifting will be affected by ergonomics concerns. It is the responsibility of the employer to provide a safe and healthful work environment for employees, and this includes conducting worksite analyses to identify all working conditions that may adversely impact workers over the long term.

Various musculoskeletal and stress-related disorders can develop if working conditions are not modified to reduce the impact of these activities. It is recommended that employers communicate clear ergonomics-based policies with employees.

Development and implementation of an effective, ergonomically sound work plan can include such elements as delegating responsibilities to designated employees, employee job rotation, ensuring proper staffing, installing conscientiously constructed workstations complete with anti-fatigue mats, providing proper tools in a range of sizes, and encouraging the early reporting of any musculoskeletal disorders.


Cannabis grow operations require a great deal of energy. This translates to hazards in many forms: “temporary wiring (e.g., extension cords), missing breakers, blocked electrical panels, improperly wired units, electricity use in high humidity and watering areas, improper repairs, unguarded fans, overloaded circuits, inadequate wiring, lack of training and general electrical safety”.

Beyond these electrical hazards listed in their routine operational states, employers are further required to protect employees from hazardous energy sources on the equipment during maintenance and repairs (lockout/tag-out). Numerous best practices should be adhered to for the safe management of potential electrical hazards.

An electrical safety program should be implemented and should consider proper bonding and grounding of cables, overcurrent protection, electrical guarding, and installation and use of electrical cords and wiring in wet/humid locations, among other safety considerations.

Extension cords should only be used as designed, electrical equipment should be inspected before use, and defective equipment should be removed from service. Instruct employees not to stand in wet areas when using electrical equipment. A written lockout/tag-out program should be developed and complemented by initial and annual training.


Employees working around metal halide lights, which emit ultraviolet (or UV) radiation, are at risk for photokeratitis, a painful eye condition that can result from exposure to UV rays. If the outer bulb of a halide light is broken, photokeratitis can occur several hours following exposure.

Symptoms include tearing, blurry vision, and the sensation of having a foreign object in the eye. UV lamps can be used as germicidal tools, but exposure can cause ocular inflammation and tearing and can also result in sunburn-like effects on the skin, which are exacerbated by certain medications.

Additionally, fluorescent lighting is often used in cannabis cultivation facilities, presenting hazards when the bulbs break or are damaged. Lead, cadmium, and mercury, which are toxic to humans, are commonly utilized in the composition of fluorescent bulbs, and these metals can be inhaled as vapors when the bulbs are broken.

Employees must know how to properly dispose of these items (classified as “universal waste”). Cannabis industry employers whose operations feature UV and/or dangerous metals-containing lighting are encouraged to consider alternative options. If such options are not feasible, employees must wear appropriate PPE.

If a bulb is broken or spent, proper fall protection safety measures must be taken when replacing the item. All bulbs and lighting fixtures must be installed and operated in strict accordance with manufacturer specifications and used and broken lamps/bulbs must be labeled and disposed of properly. Protocols should be developed for the safe cleanup and disposal of used and broken lamps/bulbs.


Extraction Equipment

Few other industries engage in processes similar to the plant oil extraction for which the cannabis industry is known. High heat and pressure are used in the extraction process, creating fire and explosion hazards.

Extraction typically involves the use of high-pressure machinery, butane, CO2, and/or flammable/combustible liquids, all of which are hazardous.

Local fire codes must be followed, and a fire protection policy plan should be established. Employees performing extraction operations must be properly trained and must wear appropriate PPE. All electrical equipment and other components used in the extraction process must be operated as specified by the manufacturer and by applicable electrical standards.

The extraction rooms should be dedicated specifically to extraction, and these rooms should meet state and local fire code regulations. As cannabis-related legislation is gradually developed and codified, regulations will likely change – stay apprised of regulatory developments in your area.


Other Physical Hazards

These workplaces are generally found in many work environments:

  • Flammable/Combustible Liquids
  • Occupational Injuries
  • Workplace Violence
  • Walking/Working Surfaces
  • Working at Heights
  • Noise
  • Emergencies
  • Powered Industrial Trucks
  • Machines and Hand Tools
  • Confined Spaces


Cannabis Industry Hazards: Conclusion

Cannabis industry employers will need to consider the above-listed and described hazards in designing their Safety and Health Program as well as any others that may be inherent to operations at their facility.

There is more information about the hazards included in this article as well as information on addressing these elements when developing a Safety and Health Program. As the cannabis industry gradually develops, policies and procedures to manage workplace hazards will evolve along with it.

What is important is to recognize the dangers present in the cannabis industry workplaces as soon as possible and to strive to address those issues. Doing so will prevent injuries and illnesses that could otherwise have been avoided.

Let us know what you think.