Monday, March 1, 2021

From Seed to Storage: Sources of Contamination in Cannabis

Unless cannabis is grown in a clean room with appropriate air filtration and other good laboratory practices, it is inevitable that contaminants will be found on cannabis flowers and products made with them. Many cultivators are discovering that contamination is a huge risk no matter how careful they are. The most common types of contamination are microbial but also include pesticides, heavy metals, and residual solvents. Contamination can happen during the cultivation, harvesting, drying and curing, or extraction processes. Cannabis plants and products can pick up molds or bacteria while growing (particularly if grown outdoors or in an unsanitary indoor environment) or during subsequent handling and processing. Cannabis is often exposed to contaminants when held in long-term storage. There are multiple ways cannabis can become contaminated from employees to supplies to environmental factors that are outside of your control. The best way to avoid an issue is by being aware of how cannabis can be contaminated in the first place.

  1. EMPLOYEES Handling cannabis improperly is one of the most common ways to contaminate it. Handwashing is the most basic and effective strategy to prevent cross contamination at your farm or facility. Employees should wear clean scrubs and face masks when handing the flower, especially during post-harvest processing. Gloves should also be worn and changed every time they come into contact with something other than the plant. Ensure your staff stays informed and follows best practices is ultimately the best line of defense.

  2. EQUIPMENT AND SUPPLIES There are a lot of tools that are used to grow and process cannabis, such as buckets, scales, and scissors. Make sure that there are supplies for each room and that these supplies aren’t being transferred from one area to another, which can increase the possibility of cross-contamination. Unsanitized equipment and supplies can easily cause contaminants in the form of mold, bacteria and even heavy metals from old equipment. If your machinery is contaminated with spores, you can easily cross contaminate your crop during any phase of the harvest process. This can either destroy your crop or become a major health threat if your final product is compromised. Establish equipment, surfaces and storage cleaning protocols using effective methods to eliminate pathogens.

  3. HARVEST AND POST-HARVEST A large percentage of mold begins after harvest as a result of poor air quality and high moisture levels. This situation becomes a prime time for the plant to become contaminated with mold. Mold can grow on almost any substance where moisture is present, and it reproduces by spores that can easily travel through the air with the right gust of wind and attach to your skin or plants. Extra care must be taken to ensure that–during drying and curing–temperature, humidity, and air circulation are being controlled. Later after the drying phase, you will also want to confirm that your final product is safe by testing for mold, mildew and other microbial pathogens.

  4. ENVIRONMENTAL A lot of cultivation facilities are in areas that do not have the best environments for growing cannabis. Between indoor and outdoor, each type of grow has its pros and cons. Indoor cannabis growers can potentially control the room's temperature, humidity, light intensity, and CO2 levels to achieve idyllic growth rates and conditions. The right combination of moisture, temperature, humidity, and light can help accelerate the growth of both cannabis and its pests. If contaminants or toxins enter one of your grow rooms, it may be difficult to detect and eliminate. Because fungal spores are extremely small, they can eventually get into a facility through the HVAC system. If growing indoors, you must completely sanitize your space to kill all microbes before you start. While this will prevent most issues, unfortunately traditional cleaning methods may not prevent all airborne spores that exist in small cracks, for example. You must also make sure there is always proper ventilation.

    Growing cannabis outdoors is the most natural and least expensive way. Plants grown outdoors with natural sunlight will grow to their full genetic potential and will have a full and natural terpene profile. Much less energy is required (no lights, no cooling/heating) and nutrients can be regenerated and recycled. However, plants grown outdoors are exposed to all of the elements, all the time. This includes the environment, weather, pests and animals, which can have a very big effect on the final product. For growing outdoors, it is common for cannabis producers to use pesticides and insecticides on their plants. Unfortunately, these pesticides can go on to create issues themselves if they are not thoroughly removed from the plant matter during processing as many fungicides and insecticides can be harmful to human health. Although pesticides are one way to control contamination, they’re not a perfect solution, and every state treats them differently.

As the legalization and medicinal utilization of cannabis increases around the world, so does the potential threat of contaminants making their way to consumers. Policing the quality and safety of cannabis products is far from straightforward. At the federal level in the United States, cannabis is still considered an illegal drug, so states have to determine on their own how to protect millions of cannabis users. The result is an uncertain and occasionally incoherent regulatory landscape with no consensus. Cannabis cultivators are familiar with the challenges faced as contaminants pose a potential threat to their consumers. By learning about the sources of contamination as well as prevention and remediation options, growers can more confidently face testing and consistently provide a safe product.

For further reading on this topic and references, read the Common Sources of Contamination in Cannabis Application Note. Visit the Cannabis Applications page to learn more about the benefits of utilizing chlorine dioxide gas and ultraviolet light for microbial decontamination and mold remediation.