As a result of the rapidly developing cannabis industry, many forensic toxicology labs are looking for fast, reliable and cost-effective methods to determine cannabis potency and pesticide residue in edibles. Although the pros and cons of legalization are still heavily debated throughout the country, all scientists agree that uniform testing policies and procedures need to be established as soon as possible.
Within environmental and food testing laboratories, the use of QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) has been practiced widely for the past 15 years. In 2003, Dr.’s Michelangelo Anastassiades and Steven Lehotay published the first QuEChERS application, which detailed the determination of pesticide residues in produce. Since then, QuEChERS has become the gold standard for the testing and analysis of a wide variety of edible matrices. United Chemical Technologies (UCT) was the first company to commercialize the product and it became apparent that the application of this technology to cannabis edibles was a natural solution to pesticide residue testing. All of the data from the QuEChERS cannabis edibles pesticide and potency analyses can be found here.
Sample preparation
Hard candy before freezer mill grinding
Preparation of a sample for QuEChERS analysis varies depending on the type of edible product being tested. Baked goods, chocolate bars and hard candies should be ground into a fine powder prior to analysis. Although this can be achieved using a product such as a SPEX 6770 freezer mill, a blender can suffice when analyzing typical plant-based samples. Liquid samples, such as sodas or teas, should be degassed prior to analysis, whereas any gummy-based candies should be cut into fine pieces. With the exception of the liquid samples, all other matrices should then be hydrated for one hour within a QuEChERS extraction tube.
Hard candy after freezer mill grinding
Following sample preparation, acetonitrile is added to all samples along with a proprietary blend of QuEChERS extraction salts. These salts remove water from the organic phase, help to facilitate solvent partitioning and protect base-sensitive analytes from degradation. After shaking and centrifuging the sample, three distinct layers are formed. The top layer, which is the organic phase, can then be aliquoted off for further sample clean-up or dilution.
A mint milk chocolate sample after QuEChERS extraction
For pesticide analysis, an aliquot of the organic layer was subjected to dispersive solid phase extraction (dSPE). This process utilizes an additional blend of proprietary sorbents that remove chlorophyll, sugars, organic acids and fatty compounds from the sample. The resulting extract is free of pigmentation and is ready for analysis on the LC-MS/MS. All samples that were analyzed for cannabinoids did not undergo dSPE; rather, a serial dilution was carried out due to the high concentration of cannabinoids in the original organic layer. The original QuEChERS extract required a dilution of 100-200x in order to have a sample that was ultimately suitable for analysis on LC-MS/MS. A UCT Selectra Aqueous C18 HPLC Column and Guard Column were used in a Thermo Scientific Dionex UltiMate 3000 LC System. An aqueous C18 column was selected due to the extreme polarity of the pesticides being analyzed.
Comparison of QuEChERS extracts before and after dSPE cleanup (gummy sample)
Summary
This application utilizes the advantages of UCT’s proprietary QuEChERS combination to extract 35 pesticides and 3 cannabinoids, including tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) in edibles, followed by either serial dilutions for cannabis potency analysis, or a dSPE cleanup for pesticide residue analysis. This hybrid method allows QuEChERs, which are extensively used in the food testing industry, to be utilized in a forensic setting.
Plants and animals have roughly 25,000 to 30,000 genes. The genes provide the information needed to make a protein, and proteins are the building blocks for all biological organisms. An ideal analogy is a blueprint (DNA) for an alternator (the protein) in a car (the plant). Proteins are the ‘parts’ for living things. Some proteins will work better than others, leading to visible differences that we call phenotypes.
Many traits, and the genes controlling them, are of interest to the cannabis industry. For hemp seed oil, quality, quantity and content can be manipulated through breeding natural genetic variants. Hemp fibers are already some of the best in nature, due to their length and strength. Finding the genes and proteins responsible for elongating the fibers can allow for the breeding of hemp for even longer fibers. In cannabis, the two most popular genes are THCA and CBDA synthases. There are currently over 100 sequences of the THCAS/CBDAS genes, and many natural DNA variations are known. We can make a family tree using just the THCAS, gene data and identify ‘branches’ that result in high, low or intermediate THCA levels. Generally most of the DNA changes have little to no effect on the gene, but some of the changes can have profound effects.
In fact, CBDAS and THCAS are related, in other words, they have a common ancestor. At some point the gene went through changes that resulted in the protein producing CDBA, or THCA or both. This is further supported by the fact that certain CBDAS can produce some THCA, and vice-versa. Studies into the THCAS and CBDAS family are ongoing and extensive, with terpene synthase genes following close behind.
Identifying gene (genetic) variants and characterizing their biological function allows us to combine certain genes in specific combinations to maximize yield, but determining which genes are important (gene discovery) is the first step to utilizing marker-assisted breeding.
Gene Discovery & Manipulation
The term genetics is often misused in the cannabis industry. Genetics is actually “the study of heredity and the variation of inherited characteristics.” When people say they have good genetics, what they really mean is that they have good strains, presumably with good gene variants. When people begin to cross or stabilize strains, they are performing genetic manipulation.
A geneticist will observe or measure two strains of interest, for example a plant branching and myrcene production. The high-myrcene plant is tall and skinny with no branching, reducing the yield. Crossing the two strains will produce F1 hybrid seeds. In some cases, F1 hybrids create unique desirable phenotypes (synergy) and the breeder’s work is completed. More often, traits act additively, thus we would expect the F1 to be of medium branching and medium myrcene production, a value between that of the values recorded for the parents (additive). Crossing F1 plants will produce an F2 population. An F2 population is comprised of the genes from both parents all mixed up. In this case we would expect the F2 progeny to have many different phenotypes. In our example, 25% of the plants would branch like parent A, and 25% of the F2 plants will have high myrcene like parent B. To get a plant with good branching and high myrcene, we predict that 6.25% (25% x 25%) of the F2 plants would have the correct combination.
The above-described scenario is how geneticists assign gene function, or generally called gene discovery. When the gene for height or branching is identified, it can now be tracked at the DNA level versus the phenotype level. In the above example, 93.5% of your F2 plants can be discarded, there is no need to grow them all to maturity and measure all of their phenotypes.
The most widely used method for gene discovery using natural genetic variation is by quantitative trait loci mapping (QTL). For these types of experiments, hundreds of plants are grown, phenotyped and genotyped and the data is statistically analyzed for correlations between genes (genotype) and traits (phenotype; figure). For example, all high-myrcene F2 plants will have one gene in common responsible for high myrcene, while all the other genes in those F2 plants will be randomly distributed, thus explaining the need for robust statistics. In this scenario, a gene conferring increased myrcene production has been discovered and can now be incorporated into an efficient marker-assisted breeding program to rapidly increase myrcene production in other desirable strains.
The CannaGrow Conference & Expo, held in San Diego on May 7th and 8th, educated attendees on the science of cannabis cultivation. The conference brought subject matter experts from around the country to discuss cannabis breeding and genetics, soil science and cultivation facility design.
Discussions at the conference delved deep into the science behind growing while providing some expert advice. Drew Plebani, chief executive officer of Commercial Cultivator, Inc., gave a comprehensive review of soil ecology and how understanding soil fertility is crucial to successfully growing consistent cannabis. “Soil fertility is measured by laboratories in terms of soil minerals, plant-available nutrients, percent of organic materials, pH levels and most importantly the balance of the soil’s chemical makeup,” says Plebani. “There is no silver bullet in soil ecology; increasing your soil fertility comes down to understanding the composition of soil with analytical testing.” Plebani went on to add that soil systems for cannabis need to be slightly fungal-dominant in developing an endomycorrhizal system, which is optimal for cannabis plant growth.
Plebani notes that growth and viability are reliant on maximum root mass.
Tom Lauerman, colloquially known as Farmer Tom and founder of Farmer Tom Organics, kicked off the conference with an introduction to cultivation techniques. Lauerman also delved into his experience working with federal agencies in conducting the first ever health hazard evaluation (HHE) for cannabis with the National Institute for Occupational Safety and Health (NIOSH). Through the HHE program, NIOSH responds to requests for evaluations of workplace health hazards, which are then enforced by the Occupational Safety & Health Administration (OSHA). Lauerman worked with those federal agencies, allowing them to tour his cultivation facilities to perform an HHE for cannabis processing worker safety. “I was honored to introduce those federal agencies to cannabis and I think this is a great step toward normalizing cannabis by getting the federal government involved on the ground level,” says Lauerman. Through the presentation, Lauerman emphasized the importance of working with NIOSH and OSHA to show federal agencies how the cannabis production industry emerged from the black market, branding itself with a sense of legitimacy.
Attendees flocked to Jacques and his team after the presentation to meet them.
Adam Jacques, award-winning cultivator and owner of Grower’s Guild Gardens, discussed his success in breeding CBD-dominant strains and producing customized whole-plant extractions for specific patients’ needs. “I find higher percentages of CBD in plants harvested slightly earlier than you would for a high-THC strain,” says Jacques. “Using closed-loop carbon dioxide extraction equipment, we can use multiple strains to homogenize an oil dialed in for each patient’s specific needs.” As a huge proponent of the Entourage Effect, Jacques stressed the importance of full plant extraction using fractionation with carbon dioxide. He also stressed the importance of analytical testing at every step during processing.
Hildenbrand discussing some of the lesser-known terpenoids yet to be studied.
Zacariah Hildenbrand, Ph.D., chief scientific officer at C4 Laboratories, provided the 30,000-foot view of the science behind compounds in cannabis, their interactions and his research. With the help of their DEA license, he started the C4 Cannabinomics Collaborative, where they are working with Dr. Kevin Schug at the University of Texas-Arlington to screen various cannabis strains to discover new molecules and characterize their structure. “Secondarily, we are using gene expression profiles and analysis to understand the human physiological response and the mechanism through which they elicit that response,” says Hildenbrand. “As this research evolves, we should look to epigenetics and understanding how genes are expressed.” His collaborative effort uses Shimadzu’s Vacuum Ultraviolet Spectroscopy (VUV), and they use the only VUV instrument in an academic laboratory in the United States. “Pharmaceuticals are supposed to be a targeted therapy and that is where we need to go with cannabis,” says Hildenbrand. Him and his team at C4 Laboratories want to work on the discovery of new terpenes and analyze their potential benefits, which could be significant research for cannabis medicine.
Other important topics at the conference included facility design and optimization regarding efficient technologies such as LED lighting and integrated pest management.
With the news of Pennsylvania’s medical cannabis legalization measure passing, lawmakers are clamoring for strict regulatory oversight in the form of traceability to prevent diversion and misuse. State Senator Daylin Leach (D- Montgomery/Delaware) introduced the bill and believes it will have the most intensive protections for safety in the country. “Our goal was to create a system that helps as many patients as possible, as soon as possible and as safely as possible,” says Steve Hoenstine, spokesperson for State Senator Leach. “The seed-to-sale tracking system and the bill’s other protections do just that.”
At the recent Cannabis Labs Conference, Cody Stiffler, vice president of government affairs at BioTrackTHC, discussed why traceability is so important. Stiffler previously served as the chief executive officer of the American Medical Management Association, where he fought the Florida prescription drug abuse epidemic. “We originally started tracking prescription medications and methamphetamine precursors to combat the prescription drug abuse and meth epidemic in Florida,” says Stiffler. He focused on providing accountability and traceability, making sure every prescription was legitimate and keeping drugs off the black market. Implementing tracking protocols allowed for the accountability of pharmacists, physicians and patients.
Cody Stiffler presenting at the Cannabis Labs Conference
The primary goals of a traceability system, according to Stiffler, are to prevent diversion and promote public safety. “We want to advance the cannabis industry with respect to traceability and regulatory compliance by integrating laboratory testing with traceability,” says Stiffler. “Our software helps get safe products to patients and consumers in a responsible manner.”
Stiffler’s role at BioTrackTHC is to provide industry insights to states looking to legalize cannabis and support them with identifying the best practices that meet requirements in their state. Traceability is commonly defined as the ability to verify history, location and application of a product from source to distribution. BioTrackTHC’s tracking software covers everything from seed to sale, involving regulatory bodies in oversight. In the beginning of cultivation, each plant is assigned a bar code or sixteen-digit identifier. According to Stiffler, Colorado’s system uses radio-frequency identification (RFID) tags while Washington’s system gives the business a choice because the software can work with any type of identifier, whether it is a barcode, QR code or RFID tag. “Our system generates those numbers and prevents diversion with a closed loop system,” says Stiffler.
A plant tagged with a barcode and date for tracking
Washington, Illinois, New York, New Mexico and Hawaii are the five states that use BioTrackTHC’s software. “If the state wants to see the chain-of-custody, they can go back in the system and see every touch point and the full life cycle of the product in real time,” says Stiffler. “Our system also incorporates lab testing to ensure no product reaches shelves unless test values are associated with it.”
A flowchart showing tracking from seed to sale.
For many states, problems lie not in diversion, but inversion, where black market growers bring their products into the legal market. “A lot of people growing black market product are inverting it into the regulated market,” notes Stiffler. This kind of black market activity can flood the legal market with un-tested cannabis.
Product recalls are examples of when traceability software can be very useful. Pesticides, microbiological contaminants, heavy metals and other contaminants are at issue. Stiffler invokes an example from a company in Washington making THC-infused drinks. “Because of an issue in the manufacturing process, the bottles were exploding in refrigerators and on shelves,” says Stiffler. “Because the product’s lineage was completely tracked, we could isolate all of the products in that specific batch from that specific manufacturer and then forward trace to every retailer that had it in inventory,” he adds. “Whenever someone who did not get the recall notice would attempt to scan that barcode at point of sale, a message appeared noting its recall status and that it is not for sale.” The software’s financial data analytics can provide real time visibility for profit margins or losses resulting from recalls.
According to Stiffler, these kinds of protections in place give law enforcement and government agencies piece of mind that they are helping to prevent diversion and promote public safety. Traceability software is one of the very important safeguards protecting food safety and product safety.
DNA stores information about how to build an organism. Just as a series of 0’s and 1’s represents digital data, DNA data is represented by four letters (A, C, G and T), which inherently allows DNA to store more information per unit (Figure 1).
Figure 1
The amount of DNA required to build a human is mind-boggling. The human genome has 3.2 billion A’s, C’s, G’s, or T’s, (called nucleotides). Cannabis has 820 million nucleotides. This is true for every cell in the organism. The DNA from a single human cell when spread out would stretch six feet long. A cell is not visible to the naked eye, yet it contains a microscopic thread of DNA six feet long! If you put all the DNA molecules in your body end to end, the DNA would reach from the Earth to the Sun.
DNA is common in all living things, and all living things are related through DNA. Humans and plants share 50% of their genes. In humans, 99.9% of the DNA is identical, thus just 0.1% of DNA differences accounts for all of the variation observed in humans. Cannabis, as a species, is more variable with approximately 1% of the DNA being different among strains. DNA is a super efficient and reliable information storage system. However, mistakes (mutations) do occur and while infrequent, these mutations account for all the differences observed within a species and is called natural genetic variation. Variation within the genomes of a species can help the species survive in unfavorable conditions (evolution) and is also the source of differences in traits, which is the material that is required for successful breeding.
Natural Genetic Variation
DNA mutations occur in every generation and these changes will be different in each individual creating natural genetic variation. Mutations (or more accurately referred to as DNA changes) will be inherited by offspring and will persist in the population if the offspring reproduce.
Figure 2
DNA differences maintain diversity in the gene pool, allowing organisms to respond to new environments (migration) or environmental changes (adaptation). The two most commonly described cannabis families are Indicas and Sativas. Indicas, being from cooler temperate regions, have wide leaves allowing the maximum capture of light during the shorter growing season. Sativas, being equatorial, have smaller leaves, which may be an advantage for such things as powdery mildew in a humid environment. Figure 2 shows the enormous amount of natural variation in leaves for one species with a worldwide population (Arabidopsis thaliana).
A DNA change that occurred a long time ago will be more useful to divide people/plants into different groups. For example, there are ancient DNA changes that differentiate humans originating from Europe or Asia. Other newer DNA changes allow us to further divide Europeans into those originating from Northern versus Southern Europe. Thus, different DNA changes have different values for determining relatedness or ancestry, yet every DNA change provides some information for determining heredity.
Figure 3
Family Trees
By comparing DNA changes among different strains, we can measure the relatedness between strains. For example, if strain A has a DNA change indicative of Kush ancestry and strain B has a DNA change indicative of hemp ancestry, we can assign strains to branches of the cannabis family tree comprised of strains that contain similar DNA changes. Figure 3 shows 184 strains that have been characterized for these changes, and the position of each strain is based on its shared DNA with neighboring strains. The two best-defined families of cannabis are hemp (blue) and kush (black). Strains within a family are more closely related. Strains in separate families, such as kush and hemp, are more distantly related.
Editor’s Note: This is the first installment in a series of articles focused on answering common questions regarding cannabis genetics. If you have questions regarding cannabis genetics, or wish to speak more about the topic please post in the comments section below. The next installment will delve into the THC synthase, gene discovery and manipulation and mapping chromosomes.
Would you be proud to have your customers and patients tour your production facility? When health inspectors or enforcement personnel arrive at your location is there sense of panic or pride?
When you have detailed systems in place, inspections should be informative, not stressful. Keep in mind that in the cannabis industry, products are often created for patients. Patients may have a compromised immune system and thus are more susceptible to food borne illnesses, pesticides and other contaminants.
Are you and your team doing everything you can to produce a wholesome and safe product?
According to the World Health Organization, Good Manufacturing Process (GMP) “is a system for ensuring that products are consistently produced according to quality standards.”
GMP is the proactive part of quality assurance. It is designed to minimize the risks involved in all steps of the manufacturing process. A basic tenant of GMP is that quality cannot be tested into a product. It must be built into each batch of product during all stages of the manufacturing process.
GMPs involve much more than most people think. A common misconception is that GMP only covers the process of manufacturing itself. GMPs actually cover all aspects of the production process:
Materials
Premises
Equipment
Storage
Record Keeping
Staff Training to Hygiene
How Complaints Are Handled
GMP & The Cannabis Industry
In most industries, agencies that control licensing for the manufacture and sale of a product recommend GMPs, or guidelines to business owners. These guidelines provide minimum requirements that a manufacturer must meet to assure that products are of high quality and do not pose any risk to the consumer or public. The guidelines generally become the basis of regulation for that industry.
In the United States, the Food and Drug Administration (FDA) recommends guidelines for anything food, drug or pharmaceutical related.
Because cannabis still remains illegal at the federal level, none of the federal agencies that would normally develop good manufacturing guidelines have done so. This has left state lawmakers and business owners on their own to navigate this new and rapidly developing industry.
The Foundation of Cannabis Unified Standards (FOCUS) has developed standards with a mission to protect public health, consumer safety and safeguard the environment by promoting integrity in the cannabis industry.
The comprehensive implementation of cannabis specific good manufacturing practices, like the FOCUS standards, across all aspects of the industry will assist business owners and regulators alike, addressing quality proactively at every step in the process, which is critical to protecting consumer safety and public health – and the overall success of a nascent and divisive industry like cannabis.
The FOCUS standards are completing the final phase of development, a thirty-day public review and comment period before being released for use in the marketplace in June. These voluntary consensus-based standards are built on GMPs drawn from agriculture, food production, chemical management, OTCs, pharmaceuticals, and other relevant industries. In addition, the standards draw best practices from the cannabis industry, as well as those published in OSHA, FDA, FTC, CDC, ISO, code of federal regulations and various state-level cannabis regulations.
There are many aspects of creating and implementing GMPs. Here are three to be aware of:
Get the facility design right from the start: It’s much easier to be GMP compliant if the design and construction of the facilities and equipment are right from the start. It is important to embody GMP principles and use GMPs to drive every decision.
Document what you do and do what you document: Having good procedures in place to ensure a controlled and consistent performance is an essential part of GMP. Procedures should be clear, concise, logical, and available to everyone.
Keep good records: Keeping accurate records is an essential part of GMP. It helps convey that you are following procedures and demonstrates that processes are known and under control. If it’s not written down, it did not happen.
Standards and quality programs in any industry are dynamic by nature. Nothing is static. Standards must constantly be updated to reflect ever-changing market conditions. This is why it is so crucial that regulations are based on them.
To be a standard, there are certain core principals that must be present. However, the goal of a standard is to guide an industry without impeding or controlling it. This is why there is so much inherent value in implementing standards. They bring enough structure to help reduce costs and increase efficiency, but not so much control that individual nuances or creativity is affected.
It is much less expensive to be proactive. Recovering from a recall or contaminated product can not only be costly, it is a massive hit to the company’s reputation. It may take years for sales to recover, and for consumers to trust the product again. Where could you and your team enhance your standards and processes?
In the first part of this series, I presented some issues with perpetual harvest models for cultivation with respect to inefficiencies in technology and environmental monitoring. I made the case for compartmentalizing cultivation facilities to not only increase energy efficiency, but also to mitigate contamination and control risks for pest incursions. In the second part of this series, I will elaborate on how compartmentalizing your facility can help you stay compliant with pesticide use regulations and promote worker safety.
Problems with Pesticide Use and Worker Safety Regulations
Where there are pests there are pesticides, whether they are low-toxicity materials derived from natural sources or chemical products that are illegal to use on cannabis. Even in the case of growers that are following current pesticide guidelines and using only products approved by their state department of agriculture, perpetual harvest models present issues in ensuring that the workplace is safe for employees and compliant with pesticide use regulations.
One obvious difficulty is the impossibility of containing drift from pesticides applied as foliar sprays. At this point, due to the lack of research performed on pesticides and cannabis, there are currently no defined pre-harvest intervals (PHI), even for products allowed for use on cannabis. A pesticide’s PHI is the number of days that must pass between the time of the last application of a pesticide and when the crop is cut for harvest. While no official, research-based PHIs have been outlined for pesticide use on cannabis, most conscientious cultivators refrain from spraying their crops with anything once flowers have emerged, as the resinous, sticky buds and their many crevices would presumably retain a great amount of any material applied to them. However, flowers do not generally emerge fully until the third week of the flowering process, and many growers apply preventative applications in the first two weeks of flower. In a perpetual harvest facility, what is to stop drift from applications made early in flower from contacting plants close to harvest? One could simply not spray in flower at all, but eliminating early-flower preventative treatments could increase the chances of a pest incursion, which, as discussed above, can be seemingly intractable in this type of facility.
It is important to consider the restricted entry interval (REI) when dealing with pesticide use. The REI of a pesticide is the period of time after an area is treated during which restrictions on entry are in effect to protect people from exposure to hazardous levels of pesticide residues. Most of the products and materials approved for use on cannabis in Colorado have no REI or a relatively short one. At the time I left my former facility, the longest REI for any product in use was twelve hours (for Evergreen Pyrethrum Concentrate), though most had REIs of four hours or less. This issue could be avoided in a perpetual harvest facility by simply always scheduling pesticide applications at the end of the workday; if a product is sprayed at 6 PM, for example, then the treated area should be safe for entry by the following morning when employees arrive. However, what is to be done if a pest incursion is discovered in the middle of the day and an immediate treatment is necessary to prevent its spread? Would the management or ownership of such a facility be willing to clear out the entire perpetual harvest area for 4-12 hours, potentially leaving other tasks unperformed or incomplete, so that a few plants could be sprayed? Even if operators went to such lengths to observe REIs properly, instances such as the hypothetical described above would create massive interruptions in daily workflows and scheduled tasks that are highly undesirable in a well-managed commercial setting. Compartmentalization allows for essential tasks in a single room that might need an emergency treatment to be completed in a timely manner, and cordoned off after the pesticide application to observe the REI.
A final point concerning this topic is that perpetual harvest facility designs make it difficult to observe certain requirements of the Worker Protection Standard (WPS). WPS is administered by the EPA (but is enforced by the Colorado Department of Agriculture (CDA) in that state) and consists of training intended to reduce the risk of pesticide poisoning and injury among agricultural workers and pesticide handlers. WPS training is required for all agricultural workers and pesticide handlers, including those in the legal cannabis industry. One requirement of WPS is that employers provide decontamination supplies for their employees in case of accidental pesticide exposure or poisoning. Sandra McDonald is a pesticide safety expert and owner of Mountain West PEST, which provides WPS and other training to farmers of all crops in Colorado. She states that decontamination supplies cannot be stored in areas that are to be or have been treated by pesticides (such as perpetual harvest rooms, for the purposes of this discussion), as the applications could possibly contaminate the decontamination supplies with pesticide residues, making them useless or even dangerous.
So, in a perpetual harvest facility, where does one store decontamination materials? Again, while there are solutions to this question, they are not ideal. The materials would of course have to be located outside the perpetual harvest room, the entirety of which is a “treated area” at one time or another. But, in facilities the size of the ones under discussion, it could be difficult for an employee who has been exposed to pesticides to reach an eyewash station if he or she has to navigate the expansive perpetual harvest room, as well as a doorway or two, in order to gain access to safety supplies located somewhere that pesticide contamination is not a risk. McDonald notes that most of the products approved for use on cannabis by the CDA would not require immediate decontamination. However, as not to downplay the very real risks posed by some approved products, she also points out that first aid statements on the labels of such pesticides recommend at least 15-20 minutes of continuous rinsing in the case of a worker getting pesticides in his or her eyes, and treatment that takes place sooner rather than later is obviously preferable. Additionally, there are some approved materials with high pH levels that could be immediately damaging if a worker splashed them in his or her eyes.
The issues raised by perpetual harvest designs in respect to pesticide use and worker safety are amplified greatly if businesses operating perpetual harvest facilities employ or have employed chemical pesticides that are illegal for use on cannabis. Unfortunately, the illegal application of restricted-use pesticides has revealed itself to be widespread, as examples from Colorado and Washington illustrate. One of the most commonly used illegal products, Eagle 20EW, carries with it a 24 hour REI. This means that to properly observe this safety measure, employees would be required to keep clear of the treated area for a full day, which I find unlikely to be enforced considering the daily requirements of a cultivation facility. Drift again poses a problem, but a much more serious one compared to the products on the CDA’s approved list.
Recommendations
It should be obvious by now that, when considering facility or site design, compartmentalization is desirable and necessary. This goes for greenhouse and outdoor production, as well as indoor. In fact, some outdoor farmers in the Emerald Triangle area of northern California work multiple, separate parcels to hedge against the threat of crop loss wiping out their entire year’s efforts. Though the discussion above focused mostly on flowering plants; propagation, vegetative, and mother areas should be separate as well, as they effectively contain all future harvests and are therefore of paramount importance.
The appropriate amount of compartmentalization will vary depending on the operation. In most agricultural businesses, some amount of loss is expected and incorporated into plans and budgets. In terms of areas for flowering plants, they should be compartmentalized to an extent that, should a severe infestation or systems failure occur, the loss of expected revenue from one or more rooms or areas will not cripple the business. Such loss should not happen often in a well-run, well-equipped facility. However, I have seen the drastic damage that russet mites can cause, in addition to experiencing the dread that permeates an entirely darkened warehouse after a transformer explosion, and would advise that cash flow projections take into account the possible loss of a harvest or two from a single room per year, just to be safe.
In cannabis farming, as in all agriculture, we must plan for the worst and hope for the best. Compartmentalization is a fundamental and effective safeguard against small pest incursions becoming widespread infestations, while allowing for grow areas to be fully sterilized and decontaminated after a harvest without completely interrupting all operations. It also allows for the observance of REIs, PHIs (even self-imposed ones), and certain WPS guidelines much more easily than perpetual harvest models. Finally, while costing more up front, ongoing operational expenses can be lessened, with a greater return on the energy that is used. While the benefits of wide-open spaces are frequently touted in a variety of contexts, cannabis cultivation is one where being boxed in is preferable to ensure that your employees, plants, and investment are protected.
When newspapers and television run a cannabis story, it is frequently accompanied by photos or video of vast, cavernous warehouses filled with veritable oceans of plants. Photos used to illustrate stories in the New York Times and Denver Post serve to illustrate this point.
This type of facility design is sometimes referred to in the cannabis industry as a “perpetual harvest” model. This is because plants are harvested piecemeal – one row at a time, for example – with new plants ready to flower replacing the recently harvested ones. In this model, flowering plants of various ages occupy the same space and the room is never completely harvested and empty, hence the “perpetual” moniker. This is in contrast to more compartmentalized facility designs, in which flowering plants are segregated in smaller groups in various rooms, which are then harvested completely before the room is cleaned and new plants ready to flower replace the previous ones.
The perpetual harvest setup appears impressive and lends itself well to portraying the volume of production being achieved in large facilities. This is likely why I have seen such models, or similar ones, copied in other states. Prospective entrants to the industry have also approached my firm with such designs in mind for their cultivation facilities. However, we generally advise against the perpetual harvest facility model, as this type of design imposes serious difficulties upon operators. Problems arise primarily in the areas of pest and contamination mitigation, ability to properly observe pesticide use and worker safety guidelines, and inefficiencies in lighting and HVAC usage. The problems noted are linked to the perpetual harvest design and can be mitigated with increased compartmentalization. Before getting to my recommendations, however, lets run down the issues created by the perpetual harvest model.
In many photos I see of perpetual harvest facilities, the ceilings are extremely high, as are the light fixtures in most cases. This is likely the result of one of the main perceived advantages of such spaces, which is that they require minimal construction prior to getting up and running. There are no walls to be put up or ceilings lowered, and the lack of compartmentalization makes running wires and ducting much easier.
However, whatever capital was saved in initial construction will likely be burned up by increased ongoing operational costs. High ceilings such as those in the above photos mean more cubic footage that climate control systems must cool or heat. Additionally, due to the great height of the light fixtures, plants are not getting the most bang for their buck, so to speak, compared to designs that allow lights to be lowered appropriately to provide optimal intensity and spectrum. Double-Ended High Pressure Sodium (DE HPS) lamps are probably the most common type of lighting in use for flowering by commercial cannabis cultivators today, and they are ideally situated about four feet above the canopy when running at full capacity.
For businesses aiming for a no-frills production model with minimal attention to the light management needs of individual cannabis cultivars (or strains, as they are commonly referred to), then this consideration may be moot. However, those operations attempting to produce the highest-quality flower and plant material know the value of proper light management, as well as the fact that some cultivars respond differently than others to intense light. Indeed, I have observed cultivars that produce more when light intensity was decreased, while others thrived under intense light that would have seriously damaged others. This makes the one-size-fits-all approach to light management I’ve seen in most perpetual harvest designs generally detrimental to the quality of the final product, in addition to using the same amount of energy, or more, to achieve that lower quality result.
Difficulties in Pest and Contamination Mitigation
Such a design makes it easy for a small pest incursion to become a full-blown infestation. Because plants about to be harvested are sharing space with plants just beginning their flowering process, this means that both current and future harvests will be affected, or even lost entirely if the pest problem is severe. Having plant groups of different ages share the same space is generally unadvisable. This is because older plants, particularly those close to harvest, are weaker and more susceptible to pests by virtue of the fact that their life cycles are nearing an end. On the other hand, a more compartmentalized facility design provides physical barriers that can contain mites and mildew spores to some extent, limiting the damage done by individual pest incursions.
One of the essential tasks in an indoor cultivation operation is sterilizing just-harvested spaces to ensure that the subsequent run gets off to a clean start. This task could conceivably be performed in a perpetual harvest model; say, for example, trays, trellis frames, and other equipment are scrubbed after a row has been cut down and removed for drying or processing. However, due to the fact that there are always other plants in the room, it seems impossible for any plant group to get an assuredly clean start, as other plants may be harboring bugs, mold spores, or viruses, despite not showing signs or symptoms. The presence of plants also eliminates the possibility of using cleaning agents such as bleach, which gives off harmful fumes, but is sometimes necessary to completely sterilize an area that might have previously experienced some amount of powdery mildew or botrytis.
In Part II of this series, I will discuss some problems with pesticide use and worker safety regulations as well as provide recommendations for compartmentalization in cultivation facilities. Stay tuned for Part II of A Case for Compartmentalization: Problems with “Perpetual Harvest” Models in Cultivation, coming out next week.
The Supreme Court shut down a lawsuit on Monday brought by two states against Colorado for its recreational cannabis laws. Nebraska and Oklahoma brought the case to the Supreme Court, claiming that the recreational cannabis industry in Colorado is responsible for the illegal exportation of cannabis outside of Colorado. “Colorado has facilitated purchase of marijuana by residents of neighboring states by issuing licenses to an unusually high number of marijuana retailers perched on Colorado’s borders,” the two states told the court in a supplemental brief.
In that brief, the two states argue that Colorado’s cannabis industry led to more cannabis illegally crossing state lines. They argue because of that influx of cannabis, they spend more on law enforcement and state resources, which is a detriment to their citizens. The Supreme Court did not provide an explanation for why they refused to hear the case.
Many view this as a big win for the legal cannabis industry. “The Supreme Court has protected the will of the people today and I believe the court has demonstrated that it understands legal cannabis is a fundamental right,” says Andy Williams, president of Medicine Man, the largest cannabis dispensary in Denver.
Still others see this simply as business as usual. “While I’m pleased to see the Court reject the challenge to Colorado’s cannabis law, this decision isn’t really a win for cannabis advocates- it only maintains the status quo,” says Aaron Herzberg, partner and general counsel at CalCann Holdings, a medical cannabis holding company specializing in real estate and licensing. “We are struggling with diversion in California, so hopefully states will continue to be on track to create a more regulated and taxed environment where cannabis can be manufactured and sold through channels where it is safe and tested,” continues Herzberg.
Adam Koh, chief cultivation officer at Comprehensive Cannabis Consulting (3C), warns that the Court’s denial to hear the case is not necessarily an affirmation of state’s cannabis programs. “It is evident that some diversion is taking place, which of course is against the provisions of the Cole Memorandum,” says Koh. “In order to avoid being implicated in such activities, legally licensed cannabis businesses in Colorado should not take the SCOTUS decision as a signal to relax, but should instead work to make sure that inventory control and record-keeping protocols are in place and even exceed the standards required in state regulations.”
The fact alone that Nebraska and Oklahoma even brought the case to the Supreme Court means that diversion is a major issue facing the cannabis industry. “Only by going above and beyond in terms of compliance will this controversial industry make itself credible in the eyes of its detractors,” says Koh. Some cannabis industry leaders take it upon themselves to help guide rule makers in crafting standards.
Lezli Engelking, founder of the Foundation of Cannabis Unified Standards (FOCUS), believes the Cole Memo is currently the best guidance for states and business owners to follow by the federal government in regards to cannabis. “Gaping holes in cannabis regulations are glaringly identified via the pesticide issues and recalls recently,” says Engelking. “These issues showcase each state being in violation of the Cole Memo’s expectation that they will implement strong and effective regulatory and enforcement systems that address the threat to public safety, public health, and other law enforcement interests.”
The Supreme Court’s denial of the two states’ challenge to Colorado’s cannabis legislation suggests the federal government’s intentional avoidance of involvement in current state cannabis issues. The government’s inaction does not, however, indicate their support.
Last week’s Pittcon, the world’s leading conference and expo for laboratory science, brought together thousands of laboratory equipment companies, scientists and laboratory professionals in Atlanta. This year’s meeting made history, as it featured Pittcon’s first cannabis conference.
Generating quite a bit of buzz at the show in Atlanta, the inaugural Cannabis Labs Conference brought Pittcon attendees, cannabis industry leaders and scientists together to discuss the changing landscape of cannabis testing, the need for standards and cannabis laboratory methods. The improvement of quality standards, outside industry expertise and noting the industry still has a long way to go were some of the themes that came out of the talks.
Nic Easley, CEO of Comprehensive Cannabis Consulting, delivered the keynote presentation.
Nic Easley, chief executive officer of Comprehensive Cannabis Consulting (3C), delivered the keynote, addressing concerns over consumer safety and lab testing standards in such a fast-paced market. “What we need now are outside industry experts to help guide this industry with standards and proper analytics,” he said. “With increased efficiencies and competition in the cannabis marketplace, our ethics need to be called into question as the industry reaps its profits.”
Other highlights included the sharing of new validation methods. Scott Radcliffe, technical support scientist at Romer Labs, Inc., presented his findings on the validation of immunoassays for the detection of pathogens and mycotoxins in cannabis. Amanda Rigdon, applications chemist at Restek, Inc., also led a discussion on the opportunities and challenges for method validation in the evolving cannabis industry.
Scott Radcliffe, technical support scientist at Romer Labs, discussing the validation of immunoassays for the detection of pathogens in cannabis.
Rigdon provided a glimpse into the amount of work it takes for method validation. “You can have all of the regulations in the world but that does not guarantee that you will produce good data,” Rigdon said. “We need good science, which is lacking currently in the industry.”
Amanda Rigdon, applications chemist at Restek, leading a talk on method validation
“We need to show proficiency with a standardized method and that comes through full validation which, requires a lot of money, time and work,” Rigdon added. These components of validation include accuracy, precision, recovery, selectivity, specificity and proper instrument calibration. “The bottom line is labs need a method that is reproducible and robust,” she said. Rigdon also shared her data from recent methods validation at a cannabis laboratory in Spokane, Washington.
Next year’s Cannabis Labs Conference is scheduled to take place in Chicago during the week of March 5, 2017. To hear more about the Cannabis Labs Conference, sign up for the CannabisIndustryJournal newsletter.
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