Cannabis Cultivation Virtual Conference Part 5
By Ivor Noble, Founder and CEO of CannaAirCare
The all natural preventative against airborne mustiness!
HACCP is a food safety program developed in the 1960s for the food manufacturing industry, mandated for meat, seafood and juice and adopted by foodservice for the safe serving of meals at restaurants. With state requirements for the safe production of cannabis-infused products, namely edibles, facilities may be inspected against HACCP principles. The cannabis industry and state inspectors recognize the need for safe edible manufacture. Lessons can be learned from the food industry, which has advanced beyond HACCP plans to food safety plans, starting with procurement and including the shipment of finished product to customers.
In my work with the food industry, I write HACCP and food safety plans and deliver training on food safety. In Part 1 of this series, I wrote about the identification of hazards, which is the first step in HACCP plan development. Before we continue with the next HACCP step, I will discuss Good Manufacturing Practices (GMPs). GMPs are the foundation on which HACCP is built. In other words, without GMPs in place, the facility will not have a successful HACCP program. GMPs are required in the food, dietary supplement and pharmaceutical industries, all under the enforcement of the federal Food and Drug Administration (FDA). Without federal regulation for cannabis edible manufacture, there may not be state-mandated requirements for GMPs. Let me warn you that any food safety program will not succeed without proper control of GMPs.
GMPs cover all of your programs and procedures to support food safety without having a direct, instant control. For example, when brownies are baked as edibles, food safety is controlled by the time and temperature of baking. A written recipe and baking procedure are followed for the edible. The time and temperature can be recorded to provide documentation of proper baking. In the food industry, this is called a process preventative control, which is critical to food safety and is part of a HACCP plan. Failure of proper time and temperature of baking not only leads to an unacceptable product in terms of quality, but results in an unsafe product that should not be sold.
Back to GMPs. Now think of everything that was done up to the steps of mixing and baking. Let’s start with personnel. Facilities for edibles have hiring practices. Once an employee is hired, the employee is trained, and training will include food safety procedures. When working at the job after training, the employee measuring ingredients will demonstrate proper grooming and hand washing. Clean aprons, hairnets, beard nets and gloves will be provided by the facility and worn by the employee. The same goes for the employee that bakes and the employee that packages the edible. One category of GMPs is Personnel.
Edibles facilities are not foodservice; they are manufacturing. A second GMP category is cleaning and sanitizing. Food safety is controlled through proper cleaning and sanitizing of food contact surfaces (FCS). The edible facility will have in place the frequency and methods for cleaning all parts of the facility- outside, offices, restrooms, break room and others. GMPs cover the general cleaning procedures and procedures for cleaning receiving, storage; what we would consider processing to include weighing, process steps and packaging; finished product storage and shipping. Management of the facility decides the methods and frequency of cleaning and sanitizing with greater care given to processing. Without proper cleaning and sanitizing, a facility cannot achieve food safety.
I could go on and on about GMPs. Other GMPs include water safety, integrity of the buildings, pest control program, procurement, sewage disposal and waste disposal. Let’s transition back to HACCP. In Part 1 of this series, I explained identification of hazards. Hazards are one of three types: biological, chemical and physical.
At this point, I am not surprised if you are overwhelmed. After reading Part 1 of this series, did you form a food safety team? At each edibles facility, there should be at least one employee who is trained externally in food safety to the standard that foodservice meets. Classes are offered locally and frequently. When the facility is ready, the next step of training is a HACCP workshop for the food industry, not foodservice. Edibles facilities are not foodservice; they are manufacturing. Many colleges and associations provide HACCP training. Finally, at the least, one employee should attend a workshop for Preventive Controls Qualified Individual.
To institute proper GMPs, go to ConnectFood.com for a GMP checklist. Did you draw up a flow diagram after reading Part 1? With a flow diagram that starts at Receiving and ends at Shipping, the software at ConnectFood.com takes you through the writing steps of a HACCP or food safety plan. There are many resources out there for GMPs, so it can get overwhelming. ConnectFood.com is my favorite resource.
The next step in HACCP development after identification of hazards is to identify the exact step where the hazard will be controlled. Strictly speaking, HACCP only covers process preventive controls, which typically start with a weigh step and end with a packaging step. A facility may also have a step where temperature must be controlled for food safety, e.g. cooling. In HACCP, there are commonly two process preventive controls:
Strictly speaking, HACCP does not include cleaning, sanitizing and supplier approval for procurement of ingredients and packaging. I hope you see that HACCP is not enough. There have been hundreds of recalls and outbreaks due to problems in non-processing steps. The FDA requires food manufactures to go beyond HACCP and follow a written food safety plan, which includes hazards controlled at these steps:
Does a cannabis edible facility honestly not care or not control for pesticides in ingredients because this is not part of HACCP? No. There are two ways for procurement of ingredients in which pesticides are controlled. Either the cannabis cultivation is controlled as part of the samebusiness or the facility works with a supplier to confirm the ingredient meets pesticide tolerances. Strictly speaking, this control is not part of HACCP. For this and many other reasons, HACCP is a good place to start the control of food safety when built on a solid foundation of GMPs. In the same way the food industry is required to go beyond HACCP with a food safety plan, the cannabis industry must go beyond HACCP.
The outside environment can vary widely depending on where your facility is located. However, the internal environment around any activity can have an effect on that activity and any personnel performing the activity, whether that’s storage, manufacturing, testing, office work, etc. These effects can, in turn, affect the product of such activities. Environmental control strategies aim to ensure that the environment supports efforts to keep product quality high in a manner that is economical and sensible, regardless of the outside weather conditions.
For this article, let us define the “environment” as characteristics related to the room air in which an activity is performed, setting aside construction and procedural conditions that may also affect the activity. Also, let us leave the issue of managing toxins or potent compounds for another time (as well as lighting, noise, vibration, air flow, differential pressures, etc). The intent here is to focus on the basics: temperature, humidity and a little bit on particulate counts.
Temperature and humidity are key because a non-suitable environment can result in the following problems:
USP <659> “Packaging and Storage Requirements” identifies room temperature as 20-25°C (68-77 °F) and is often used as a guideline for operations. If gowning is required, the temperature may be reduced to improve operator comfort. This is a good guide for human working areas. For areas that require other specific temperatures (e.g. refrigerated storage for raw materials), the temperature of the area should be set to those requirements.
Humidity can affect activities at the high end by allowing mold growth and at the low end by increasing static. Some products (or packaging materials) are hydroscopic, and will take on water from a humid environment. Working with particular products (e.g. powders) can also drive the requirement for better humidity control, since some powders become difficult to manage in either high or low humidity environments. For human operations without other constraints, a typical range for desirable humidity is in the range of 20 to 70% RH in manufacturing areas, allowing for occasional excursions above. As in the case of temperature, other requirements may dictate a different range.
In a typical work environment, it is often sufficient to control the temperature, while allowing the relative humidity to vary. If the humidity does not exceed the limits for the activity, then this approach is preferred, because controlling humidity adds a level of complexity (and cost) to the air handling. If humidity control is required, it can be managed by adding moisture via various humidification systems, or cooling/reheating air to remove moisture. When very low humidity is required, special equipment such as a desiccant system may be required. It should be noted that although you can save money by not implementing humidity control at the beginning, retrofitting your system for humidity control at a later time can be expensive and require a shutdown of the facility.
Good engineering practice can help prevent issues that may be caused by activities performed in inappropriately controlled environments. The following steps can help manage the process:
The main point is if you plan your facility and know your requirements, then you can avoid significant problems down the road as your company grows and activity in various areas increases. Chances are that a typical facility may not meet your particular requirements, and finding that out after you are operational can take away from your vacation time and peace of mind. Consider the environment, its good business!
Across the country, there is a patchwork of regulatory requirements that vary from state to state. Regulations focus on limiting microbial impurities (such as mold) present in cannabis in order for consumers to receive a safe product. When cultivators in Colorado and Nevada submit their cannabis product to laboratories for testing, they are striving to meet total yeast and mold count (TYMC) requirements.In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.
TYMC refers to the number of colony forming units present per gram (CFU/g) of cannabis material tested. CFU is a method of quantifying and reporting the amount of live yeast or mold present in the cannabis material being tested. This number is determined by plating the sample, which involves spreading the sample evenly in a container like a petri dish, followed by an incubation period, which provides the ideal conditions for yeast and mold to grow and multiply. If the yeast and mold cells are efficiently distributed on a plate, it is assumed that each live cell will give rise to a single colony. Each colony produces a visible spot on the plate and this represents a single CFU. Counting the numbers of CFU gives an accurate estimate on the number of viable cells in the sample.
The plate count methodology for TYMC is standardized and widely accepted in a variety of industries including the food, cosmetic and pharmaceutical industries. The FDA has published guidelines that specify limits on total yeast and mold counts ranging from 10 to 100,000 CFU/g. In cannabis testing, a TYMC count of 10,000 is commonly used. TYMC is also approved by the AOAC for testing a variety of products, such as food and cosmetics, for yeast and mold. It is a fairly easy technique to perform requiring minimal training, and the overall cost tends to be relatively low. It can be utilized to differentiate between dead and live cells, since only viable living cells produce colonies.
There is a 24 to 48-hour incubation period associated with TYMC and this impedes speed of testing. Depending on the microbial levels in a sample, additional dilution of a cannabis sample being tested may be required in order to count the cells accurately. TYMC is not species-specific, allowing this method to cover a broad range of yeast and molds, including those that are not considered harmful. Studies conducted on cannabis products have identified several harmful species of yeast and mold, including Cryptococcus, Mucor, Aspergillus, Penicillium and Botrytis Cinerea. Non-pathogenic molds have also been shown to be a source of allergic hypersensitivity reactions. The ability of TYMC to detect only viable living cells from such a broad range of yeast and mold species may be considered an advantage in the newly emerging cannabis industry.
After California voted to legalize recreational marijuana, state regulatory agencies began exploring different cannabis testing methods to implement in order to ensure clean cannabis for the large influx of consumers.
Unlike Colorado, California is considering a different route and the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus). While Aspergillus can also be cultured and plated, it is difficult to differentiate morphological characteristics of each species on a plate and the risk of misidentification is high. Therefore, positive identification would require the use of DNA-based methods such as polymerase chain reaction testing, also known as PCR. PCR is a molecular biology technique that can detect species-specific strains of mold that are considered harmful through the amplification and analysis of DNA sequences present in cannabis. The standard PCR testing method can be divided into four steps:
These steps can be repeated several times to amplify a very small amount of DNA in a sample. The primers will only bind to the corresponding sequence of DNA that matches that primer and this allows PCR to be very specific.
PCR is a very sensitive and selective method with many applications. However, the instrumentation utilized can be very expensive, which would increase the overall cost of a compliance test. The high sensitivity of the method for the target DNA means that there are possibilities for a false positive. This has implications in the cannabis industry where samples that test positive for yeast and mold may need to go through a remediation process to kill the microbial impurities. These remediated samples may still fail a PCR-based microbial test due to the presence of the DNA. Another issue with the high selectivity of this method is that other species of potentially harmful yeast and mold would not even be detected. PCR is a technique that requires skill and training to perform and this, in turn, adds to the high overall cost of the test.
Both TYMC and PCR have associated advantages and disadvantages and it is important to take into account the cost, speed, selectivity, and sensitivity of each method. The differences between the two methodologies would lead to a large disparity in testing standards amongst labs in different states. In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.
As both recreational and medical cannabis legalization continues to progress across the country, each state is tasked with developing regulatory requirements to ensure that customers and patients receive clean cannabis for consumption. This requires cannabis to undergo laboratory testing that analyzes the presence of microbial impurities including yeast and mold.
Some states, such as Colorado, Nevada, Maine, Illinois and Massachusetts use total yeast and mold count testing (TYMC) and set a maximum yeast and mold count threshold that cultivators must fall below. Other states, such as California, require the detection of species-specific strains of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which requires analyzing the DNA of a cannabis sample through polymerase chain reaction testing, also known as PCR.
Differences in state regulations can lead to different microbiological techniques implemented for testing.Before diving in further, it is important to understand the scientific approach. Laboratory testing requirements for cannabis can be separated into two categories: analytical chemistry methods and microbiological methods.
Analytical chemistry is the science of qualitatively and quantitatively determining the chemical components of a substance, and usually consists of some kind of separation followed by detection. Analytical methods are used to uncover the potency of cannabis, analyze the terpene profile and to detect the presence of pesticides, chemical residues, residuals solvents, heavy metals and mycotoxins. Analytical testing methods are performed first before proceeding to microbiological methods.
Microbiological methods dive deeper into cannabis at a cellular level to uncover microbial impurities such as yeast, mold and bacteria. The techniques utilized in microbiological methods are very different from traditional analytical chemistry methods in both the way they are performed and target of the analysis. Differences in state regulations can lead to different microbiological techniques implemented for testing. There are a variety of cell and molecular biology techniques that can be used for detecting microbial impurities, but most can be separated into two categories:
Among states that have legalized some form of cannabis use and put forth regulations, there appears to be a broad consensus that the laboratories should test for potency (cannabinoids concentration), pesticides (or chemical residues) and residual solvents at a minimum. On the other hand, microbial testing requirements, particularly for mold, appear to vary greatly from state to state. Oregon requires random testing for mold and mildew without any details on test type. In Colorado, Nevada, Maine, Illinois and Massachusetts, regulations explicitly state the use of TYMC for the detection of mold. In California, the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which are difficult to differentiate on a plate and would require a DNA-based approach. Since there are differences in costs associated and data produced by these methods, this issue will impact product costs for cultivators, which will affect cannabis prices for consumers.
With the state led legalization of both adult recreational and medical cannabis, there is a need for comprehensive and reliable analytical testing to ensure consumer safety and drug potency. Cannabis-testing laboratories receive high volumes of test requests from cannabis cultivators for testing quantitative and qualitative aspects of the plant. The testing market is growing as more states bring in stricter enforcement policies on testing. As the number of testing labs grow, it is anticipated that the laboratories that are now servicing other markets, including high throughput contract labs, will cross into cannabis testing as regulations free up. As the volume of tests each lab performs increases, the need for laboratories to make effective use of time and resource management, such as ensuring accurate and quick results, reports, regulatory compliance, quality assurance and many other aspects of data management becomes vital in staying competitive.
To be commercially competitive, testing labs offer a comprehensive range of testing services. These services are available for both the medical and recreational cannabis markets, including:
Although the testing workflows differ for each test, here is a basic overview of the operations carried out in a cannabis-testing lab:
In order to ensure that cannabis testing laboratories function reliably, they are obliged to follow and execute certain organizational and regulatory protocols throughout the testing process. These involve critical factors that determine the accuracy of testing services of a laboratory.
Gathering, organizing and controlling laboratory-testing data can be time-consuming, labor-intensive and challenging for cannabis testing laboratories. Using spreadsheets and paper methods for this purpose is error-prone, makes data retrieval difficult and does not allow laboratories to easily adhere to regulatory guidelines. Manual systems are cumbersome, costly and lack efficiency. One way to meet this challenge is to switch to automated solutions that eliminate many of the mundane tasks that utilize valuable human resources.. Laboratory automation transforms the data management processes and as a result, improves the quality of services and provides faster turnaround time with significant cost savings. Automating the data management protocol will improve the quality of accountability, improve technical efficiency, and improve fiscal resources.
A Laboratory Information Management System (LIMS) is a software tool for testing labs that aids efficient data management. A LIMS organizes, manages and communicates all laboratory test data and related information, such as sample and associated metadata, tests, Standard Operating Procedures (SOPs), test reports, and invoices. It also enables fully automated data exchange between instruments such as HPLCs, GC-FIDs, etc. to one consolidated location, thereby reducing transcription errors.
LIMS are much more capable than spreadsheets and paper-based tools for streamlining the analytical and operational lab activities and enhances the productivity and quality by eliminating manual data entry. Cloud-enabled LIMS systems such as CloudLIMS are often low in the total cost of acquisition, do not require IT staff and are scalable to help meet the ever changing business and regulatory compliance needs. Some of the key benefits of LIMS for automating a cannabis-testing laboratory are illustrated below [Table 1]:
|Barcode label designing and printing||Enables proper labelling of samples and inventory
Follows GLP guidelines
|Instant data capture by scanning barcodes||Facilitates quick client registration and sample access|
|3600 data traceability||Saves time and resources for locating samples and other records|
|Inventory and order management||Supports proactive planning/budgeting and real time accuracy|
|Custodian management||Promotes overall laboratory organization by assigning custodians for samples and tests
Maintains the Chain-of-custody (CoC)
|Test management||Accommodates pre-loaded test protocols to quickly assign tests for incoming samples|
|Accounting for sample and inventory quantity||Automatically deducts sample and inventory quantities when consumed in tests|
|Package & shipment management||Manages incoming samples and samples that have been subcontracted to other laboratories|
|Electronic data import||Electronically imports test results and metadata from integrated instruments
Eliminates manual typographical errors
|Report management||Generates accurate, customizable, meaningful and test reports for clients
Allows user to include signatures and additional sections for professional use
|21 CFR Part 11 compliant||Authenticates laboratory activities with electronic signatures|
|ISO 17025 accreditation||Provides traceable documentary evidence required to achieve ISO 17025 accreditation|
|Audit trail capabilities||Adheres to regulatory standards by recording comprehensive audit logs for laboratory activities along with the date and time stamp|
|Centralized data management||Stores all the data in a single, secure database facilitating quick data retrieval|
|Workflow management||Promotes better data management and resource allocation|
|High-configurability||Enables modification of screens using graphical configuration tools to mirror testing workflows|
|State compliance systems||Integrates with state-required compliance reporting systems and communicates using API|
|Adheres to regulatory compliance||Creates Certificates of Analysis (CoA) to prove regulatory compliance for each batch as well as batch-by-batch variance analysis and other reports as needed.|
|Data security & confidentiality||Masks sensitive data from unauthorized user access
Cloud-based LIMS encrypts data at rest and in-transit while transmission between the client and the server
|Global accessibility||Cloud-based LIMS provides real-time access to laboratory data from anytime anywhere|
|Real-time collaboration||Cloud-based LIMS enhances real-time communication within a laboratory, between a laboratory and its clients, and across a global organization with multiple sites|
Table 1. Key functionality and benefits of LIMS for cannabis testing laboratories
Upon mapping the present day challenges faced by cannabis testing laboratories, adopting laboratory automation solutions becomes imperative. Cloud-based LIMS becomes a valuable tool for laboratory data management in cannabis testing laboratories. In addition to reducing manual workloads, and efficient resource management, it helps labs focus on productive lab operations while achieving compliance and regulatory goals with ease.
For more information on this, check out a webinar here: Webinar: How to Meet Cannabis Testing Standards and Regulatory Requirements with LIMS by Stephen Goldman, laboratory director at the State of Colorado certified Cannabis testing facility, PhytaTech.
As many US States and Canadian provinces approach legalization of cannabis, the question of regulatory oversight has become a pressing issue. While public awareness is mainly focused on issues like age restrictions and impaired driving, there is another practical question to consider: should cannabis be treated as a drug or a food product when it comes to safety? In the US, FDA governs both food and drugs, but in Canada, drugs are regulated by Health Canada while food products are regulated under the CFIA.There are many food safety hazards associated with cannabis production and distribution that could put the public at risk, but are not yet adequately controlled
Of course, there are common issues like dosage and potency that pharmaceutical companies typically worry about as the industry is moving to classifying its products in terms of percentage of chemical composition (THC, CBD, etc. in a strain), much as we categorize alcohol products by the percentage of alcohol. However, with the exception of topical creams and ointments, many cannabis products are actually food products. Even the herb itself can be brewed into teas, added to baked goods or made into cannabis-infused butters, oils, capsules and tinctures.
As more people gain access to and ingest cannabis products, it’s only a matter of time before food safety becomes a primary concern for producers and regulators. So when it comes to food safety, what do growers, manufacturers and distributors need to consider? The fact is, it’s not that different from other food products. There are many food safety hazards associated with cannabis production and distribution that could put the public at risk, but are not yet adequately controlled. Continue reading below for the top four safety hazards for the cannabis industry and learn how to receive free HACCP plans to help control these hazards.
Just like any other agricultural product, improper growing conditions, handling and storage can result in mold growth, which produce aflatoxins that can cause liver cancer and other serious health problems. During storage, the danger is humidity; humidity must be monitored in storage rooms twice a day and the meter must be calibrated every month. During transportation, it is important to monitor and record temperatures in trucks. Trucks should also be cleaned weekly or as required. Products received at a cannabis facilities should be tested upon receiving and contaminated products must always be rejected, segregated and disposed of safely.
Chemical residues can be introduced at several points during the production and storage process. During growing, every facility should follow instructions for applying fertilizers and pesticides to crops. This includes waiting for a sufficient amount of time before harvesting. When fertilizer is being applied, signs must be posted. After cannabis products have been harvested, chemical controls must be in place. All chemicals should be labelled and kept in contained chemical storage when not in use to prevent contamination. Only food-grade chemicals (e.g. cleaners, sanitizers) should be used during curing, drying, trimming and storage.
Without a comprehensive food safety program, problems will inevitably arise.There is also a risk of excessive concentration of chemicals in the washing tank. As such, chemical concentrations must be monitored for. In general, water (obviously essential for the growing process) also carries risks of pathogenic bacteria like staphylococcus aureus or salmonella. For this reason, city water (which is closely controlled in most municipalities) should be used with an annual report and review. Facilities that use well water must test frequently and water samples must be tested every three months regardless.
Insects, rodents and other pests spread disease. In order to prevent infestations, a pest control program must be implemented, with traps checked monthly by a qualified contractor and verified by a designated employee. It is also necessary to have a building procedure (particularly during drying), which includes a monthly inspection, with no holes or gaps allowed. No product should leave the facility uncovered to prevent fecal matter and other hazards from coming into contact with the product. Contamination can also occur during storage on pallets, so pallets must be inspected for punctures in packaging material.
Furthermore, even the best controlled facility can fall victim to the shortcomings of their suppliers. Procedures must be in place to ensure that suppliers are complying with pest and building control procedures, among others. Certifications should be acquired and tracked upon renewal.
Employee training is key for any food facility. When employees are handling products, the risk of cross-contamination is highest. Facilities must have GMP and personnel hygiene policies in place, with training conducted upon hiring and refreshed monthly. Employees must be encouraged to stay home when sick and instructed to wear proper attire (gloves, hair nets, etc.), while glass, jewelry and outside food must not be allowed inside the facility. Tools used during harvesting and other stages may also carry microorganisms if standard cleaning procedures are not in place and implemented correctly by employees.
As the cannabis industry grows, and regulatory bodies like the FDA and CFIA look to protect public safety, we expect that more attention will be paid to other food safety issues like packaging safety (of inks and labels), allergen control and others. In the production of extracts, for example, non-food safe solvents could be used or extracts can be mixed with ingredients that have expiration dates, like coconut oil. There is one area in which the cannabis industry may lead the way, however. More and more often, risks of food terrorism, fraud and intentional adulteration are gripping the food industry as the global food chain becomes increasingly complex. It’s safe to say that security at cannabis facilities is probably unparalleled.
All of this shows that cannabis products, especially edibles (and that includes capsules and tinctures), should be treated the same as other food products simply because they have the same kinds of hazards. Without a comprehensive food safety program (that includes a plan, procedures, training, monitoring and verification), problems will inevitably arise.
As the operations manager at Los Sueños Farms, the largest outdoor cannabis farm in the country, I was tasked with the challenge of finding a yeast and mold remediation treatment method that would ensure safe and healthy cannabis for all of our customers while complying with stringent regulations.
While outdoor cannabis is not inherently moldy, outdoor farms are vulnerable to changing weather conditions. Wind transports spores, which can cause mold. Each spore is a colony forming unit if plated at a lab, even if not germinated in the final product. In other words, perfectly good cannabis can easily fail microbial testing with the presence of benign spores.
If all of those landed on cannabis it would be enough to cause over 450 pounds of cannabis to fail testing, even if those spores remained ungerminated.
It should also be known that almost every food item purchased in a store goes through some type of remediation method to be considered safe for sale. Cannabis is finally becoming a legitimized industry and we will see regulations that make cannabis production look more like food production each year.
Regulations in Colorado (as well as Nevada and Canada) require cannabis to have a total yeast and mold count (TYMC) of ≤ 10,000 colony forming units per gram. We needed a TYMC treatment method that was safe, reliable, efficient and suitable for a large-scale operation. Our main problem was the presence of fungal spores, not living, growing mold.
Below is a short list of the pros and cons of each treatment method I compiled after two years of research:
Autoclave: This is the same technology used to sterilize tattoo needles and medical equipment. Autoclave uses heat and pressure to kill living things. While extremely effective, readily available and fiscally reasonable, this method is time-consuming and cannot treat large batches. It also utilizes moisture, which increases mold risk. The final product may experience decarboxylation and a change in color, taste and smell.
Dry Heat: Placing cannabis in dry heat is a very inexpensive method that is effective at reducing mold and yeast. However, it totally ruins product unless you plan to extract it.
Gamma Ray Radiation: By applying gamma ray radiation, microbial growth is reduced in plants without affecting potency. This is a very effective, fast and scalable method that doesn’t cause terpene loss or decarboxylation. However, it uses ionizing radiation that can create new chemical compounds not present before, some of which can be cancer-causing. The Department of Homeland Security will never allow U.S. cannabis farmers to use this method, as it relies on a radioactive isotope to create the gamma rays.
Gas Treatment: (Ozone, Propylene Oxide, Ethylene Oxide, Sulfur Dioxide) Treatment with gas is inexpensive, readily available and treats the entire product. Gas treatment is time consuming and must be handled carefully, as all of these gases are toxic to humans. Ozone is challenging to scale while PPO, EO and SO2 are very scalable. Gases require special facilities to apply and it’s important to note that gases such as PPO and EO are carcinogenic. These methods introduce chemicals to cannabis and can affect the end product by reducing terpenes, aroma and flavor.
Hydrogen Peroxide: Spraying cannabis plants with a hydrogen peroxide mixture can reduce yeast and mold. However, moisture is increased, which can cause otherwise benign spores to germinate. This method only treats the surface level of the plant and is not an effective remediation treatment. It also causes extreme oxidation, burning the cannabis and removing terpenes.
Microwave: This method is readily available for small-scale use and is non-chemical based and non-ionizing. However, it causes uneven heating, burning product, which is damaging to terpenes and greatly reduces quality. This method can also result in a loss of moisture. Microwave treatment is difficult to scale and is not optimal for large cultivators.
Radio Frequency: This method is organic, non-toxic, non-ionizing and non-chemical based. It is also scalable and effective; treatment time is very fast and it treats the entire product at once. There is no decarboxylation or potency loss with radio frequency treatment. Minimal moisture loss and terpene loss may result. This method has been proven by a decade of use in the food industry and will probably become the standard in large-scale treatment facilities.
Steam Treatment: Water vapor treatment is effective in other industries, scalable, organic and readily available. This method wets cannabis, introducing further mold risk, and only treats the product surface. It also uses heat, which can cause decarboxylation, and takes a long time to implement. This is not an effective method to reduce TYMC in cannabis, even though it works very well for other agricultural products
Extraction: Using supercritical gas such as butane, heptane, carbon dioxide or hexane in the cannabis extraction process is the only method of remediation approved by the Colorado Marijuana Enforcement Division and is guaranteed to kill almost everything. It’s also readily available and easy to access. However, this time-consuming method will change your final product into a concentrate instead of flower and usually constitutes a high profit loss.
UV Light: This is an inexpensive and readily available method that is limited in efficacy. UV light is only effective on certain organisms and does not work well for killing mold spores. It also only kills what the light is touching, unless ozone is captured from photolysis of oxygen near the UV lamp. It is time consuming and very difficult to scale.
After exhaustively testing and researching all treatment methods, we settled on radio frequency treatment as the best option. APEX, a radio frequency treatment machine created by Ziel, allowed us to treat 100 pounds of cannabis in an hour – a critical factor when harvesting 36,000 plants during the October harvest.
Controlling your grow environment doesn’t start when you germinate your first seeds, it starts before you build your grow. There are steps you can take that will have a significant impact on mold growth and contamination, and these will vary based on the grow environment you choose.
Below is a roadmap to where each grow environment stands in terms of mold and contamination risk, and simple steps you can take to mitigate these factors.
The benefits of an outdoor grow are significant – using natural sunlight to grow plants is both inexpensive and environmentally sound. However, it allows the least amount of control and makes plants susceptible to weather conditions and outdoor contaminants including dust, wind, rain and insects. Depending on humidity and precipitation levels, mold can be a big issue as well.
When selecting an outdoor area for a cannabis farm, there are two important factors to consider: location and neighboring farmland. Geographical environments and sub-climates vary and once you have purchased land, you are committed, so be sure to consider these factors prior to purchase.
While arid desert climates have abundant sunlight and long growing seasons, flat, dry lands are subject to dust-storms, flash floods and exceedingly high winds that can damage crops. Conversely, more protected areas often have high humidity and rainfall late in the season, which can create huge issues with bud rot and mold. Neighboring farms also have an impact on your grow, so be sure to find out what they cultivate, what they spray, their harvest schedule and how they run their operation. Large farming equipment kicks up a lot of contaminant-laden dust and can damage crops by displacing insects to your farm if they harvest before you. Pesticide drift is also a major issue as even tiny amounts from a neighbor’s farm can cause your crops to fail testing, depending on what state you are in.
With outdoor grow environments always at the mercy of Mother Nature, any cultivator is wise to control contamination potential on the ground. Cover soil and protect your crop by planting cover crops and laying plastic mulch on as much ground as reasonable. In many cases it makes sense to irrigate uncultivated parts of your farm just to keep dust down.
Greenhouses are the future of cannabis cultivation. They allow growers to capture the full spectrum and power of the sun while lessening environmental impact and operating expenses, while still being able to precisely control the environment to grow great cannabis. With recent advancements in greenhouse technology such as automated control systems, positive pressure, geothermal heating or cooling and LED supplemental lighting, greenhouses are the future. However, older or economy greenhouses that take in unfiltered air from outside still have a medium amount of mold and contamination risk.
Before building your greenhouse, study the area while taking into account climate, weather conditions and sun exposure. Excessively windy areas can blow in contaminants, and extremely hot climates make cooling the greenhouse interior a challenging and costly endeavor.
There are several simple operational tactics to reduce contaminants in a greenhouse. Add a thrip screen to keep insects out, thoroughly clean pad walls with an oxidizing agent after each cycle, and keep plants at least 10 feet from pad walls. Plan to flip the entire greenhouse at once so that you can clean the greenhouse top to bottom before your next crop. A continuous harvest in your greenhouse allows contaminants to jump from one plant to the next and reduces the ability to control your environment and eliminate problems at the end of a cycle. Lastly, open shade curtains slowly in the morning. This prevents temperature inversion and condensation, which can cause water drops to fall from the ceiling and transfer contaminants onto plants below.
An indoor environment offers ultimate control to any grow operation. Cultivators can grow high-quality cannabis with the smallest potential for yeast and mold growth. Unfortunately, indoor environments are extremely expensive, inefficient and environmentally costly.
With indoor grow environments, keeping mold and contaminants at bay comes down to following a regimented plan that keeps all grow aspects clean and in order. To keep your grow environment clean, change HVAC filters multiple times a month. It’s also important to install HEPA filters and UV lights in HVAC systems to further reduce contamination threats. Clearly mark air returns if they are near the ground and keep those areas free of clutter. They are the lungs of your grow. Also, stop using brooms in the grow space. They stir up a lot of contaminants that have settled to the floor. Instead, use HEPA filter backpack vacuums or install a central vacuum system. Set up a “dirty room” for anything messy on a separate HVAC system, and be sure to thoroughly clean pots after every harvest cycle.
Learn more about reducing mold and contaminants in an indoor or greenhouse grow in another article from our series: 10 Ways to Reduce Mold in Your Grow.
Regardless of whether your grow is indoor or in a greenhouse, mold is a factor that all cultivators must consider.
After weeks of careful tending, pruning and watering to encourage a strong harvest, all cultivators are looking to sell their crop for the highest market value. A high mold presence, measured through a total yeast and mold count (TYMC), can cause a change of plans by decreasing crop value. But it doesn’t have to.
There are simple steps that any cultivator can take that will greatly eliminate the risk of mold in a grow. Below are some basic best practices to incorporate into your operation to reduce contaminants and mold growth: