As the cannabis market matures and the value chain becomes modernized, it’s important to address product safety in a comprehensive way. In other areas of manufacturing, Hazard Analysis & Critical Control Points (HACCP) has been the standard for reducing hazards both for employees and for the products themselves. A Critical Control Point (CCP) is any spot from conception to consumption where a loss of control can potentially result in risk (Unnevehr, 1996). In the food realm, HACCP has been used to drive quality enhancements since the 1980s (Cichy, 1982).
In a nutshell, HACCP seeks to help identify where a problem may enter a product or environment and how that problem may be addressed before it escalates. In cannabis, these hazards include many of the same problems that food products have: specifically molds, yeasts, and pathogenic bacteria (Listeria, E. coli, etc.). While the current industry standard is to test products at the end stage for these contaminants, this late-stage pass/fail regimen leads to huge lots of destroyed product and a risk for consumer distrust (Yamashiro, 2019). HACCP, therefore, should be applied at every stage of the production process.
Pathogen Environmental Monitoring (PEM) is a tool that can be used to identify CCPs in a cannabis cultivation or processing facility. The main goal of a PEM program is to find a contaminant before it reaches a surface that touches the product or the product itself. PEM is conducted using a pre-moistened swab or a sponge to collect a sample from the cannabis environment. The swab can then be sent to a lab for microbial testing. Keys to an effective PEM are:
1. Start with a broad stroke – When the FDA comes to a facility suspected of producing pathogen-laced food products, they conduct what is known as a Swab-a-thon. A Swab-a-thon is a top to bottom collection of samples, usually totaling 100 or more. Similarly, preemptively swabbing should be the first step in any PEM—swab everything to see what exists as a baseline.
2. Map your scene – identify on a map of your facility the following:
Flow of air and people (where do air and people enter and where do they go?
Identifying the above zones will help deepen your understanding of where contaminants may come into contact with cannabis and how they may migrate from a Non-CCS to a CCS.
3. Plan and execute:
Based on the results of mapping, and Swab-a-thon, identify where and when you will be collecting samples on a consistent and repeatable basis. Emphasis should be placed on areas that are deemed a risk based on 1) and 2). Samples should be collected at random in all zones to ensure comprehensive screening.
4. Remediate and modify:
If you get a positive result during PEM, don’t panic—pathogens are ubiquitous.
Remediate any trouble spots with deep cleaning, remediation devices or other protocols.
Re-test areas that were positive for pathogens to ensure remediation is successful.
Revisit and modify the plan at least once a year and each time a new piece of equipment is added or production flow is otherwise changed.
The steps above are a good starting point for a grower or processor to begin a PEM. Remember that this is not a one-size-fits-all approach to safety; each facility has its own unique set of hazards and control points.
Comprehensive guides for PEM can be found at the links below, many of the concepts can be applied to cannabis production.
You’ve survived seasons of cannabis cultivations, bringing in quality plants in spite of mold, mites, drought and other challenges that had to be conquered. Extraction methods are sometimes challenging, but you are proud to have a cannabinoid extract that can be added into your own products for sale. Edibles are just waiting to be infused with the cannabinoids, for consumers demanding brownies, gummies, tinctures and almost any food and beverage imaginable. You’ve been through the fire, and now the rest is easy peasy, right?
Actually, producing edibles may not be so seamless as you think. Just as in the rest of the food industry, food safety practices have to be considered when you’re producing edibles for public consumption, regardless of the THC, CBD, terpene or cannabinoid profile. Once you’ve acquired the extract (a “food grade ingredient”) containing the active compounds, there are three types of hazards that could still contribute to foodborne illness from your final product if you’re not careful- Biological, Chemical and Physical.
Biological hazards include pathogenic bacteria, viruses, mold, mildew (and the toxins that they can produce) that can come in ingredients naturally or contaminate foods from an outside source. Chemical hazards are often present in the kitchen environment, including detergents, floor cleaners, disinfectants and caustic chemicals, which can be harmful if ingested- they are not destroyed through cooking. Physical objects abound in food production facilities, including plastic bits, metal fragments from equipment, staples or twist ties from ingredient packages, and personal objects (e.g., buttons, jewelry, hair, nails.)
There are three main safety precautions that can help control these hazards during all the stages of food production, from receiving ingredients to packaging your final products:
1. Avoid Cross Contamination
Prevent biological, chemical or physical hazards from coming into contact with foods
Keep equipment, utensils and work surfaces clean and sanitized.
Prevent raw foods (as they usually carry bacteria) from coming into contact with “Ready-to-eat” foods (foods that will not be cooked further before consuming).
Keep chemicals away from food areas.
2. Personal Hygiene
Don’t work around foods if you’re sick with fever, vomiting or diarrhea. These could be signs of contagious illness and can contaminate foods or other staff, and contribute to an outbreak.
Do not handle ready-to-eat foods with bare hands, but use a barrier such as utensils, tissues or gloves when handling final products such as pastries or candies.
Wash hands and change gloves when soiled or contaminated.
Wear hair restraints and clean uniforms, and remove jewelry from hands and arms.
3. Time & Temperature control
Prevent bacterial growth in perishable foods such as eggs, dairy, meats, chicken (TCS “Time and Temperature Control for Safety” foods according to the FDA Model Food Code) by keeping cold foods cold and hot foods hot.
Refrigerate TCS foods at 41˚ F or below, and cook TCS foods to proper internal temperatures to kill bacteria to safe levels, per state regulations for retail food establishments.
If TCS foods have been exposed to room temperature for longer than four hours (Temperature Danger Zone 41˚ F – 135˚ F,) these foods should be discarded, as bacteria could have grown to dangerous levels during this time.
As cannabis companies strive for acceptance and legalization on a federal level, adopting these food safety practices and staff training is a major step in the right direction, on par with standards maintained by the rest of the retail food industry. The only difference is your one specially extracted cannabinoid ingredient that separates you from the rest of the crowd… with safe and healthy edibles for all.
With legalization rapidly increasing across states, the cannabis market is exploding. And with estimates of sales in the billions, it’s no surprise that greenhouses and grow rooms are emerging everywhere. As growers and extracting facilities continue to expand one important consideration that most tend to underestimate, is how flooring can impact both their production and product. Bare concrete is often a popular choice in cannabis facilities, as there are typically very minimal costs−if any at all−associated with preparing it for use. However, concrete floors can pose unique challenges when left untreated, which could inadvertently create unforeseen problems and unexpected costs.
Understanding the Risks of Bare Concrete Flooring
Whether a facility is growing or extracting, the proper flooring can play a critical role in helping maintain optimal safety and sanitation standards, while simultaneously contributing to production. That’s why its important for growers and extractors to know and understand the potential risks associated with bare concrete.
Concrete is porous: While concrete is a solid material, people may forget that it is porous. Unfortunately, these pores can absorb liquids and harbor small particles that spill on the floor. They create perfect hiding places for bacteria and other pathogens to proliferate. Pathogens can then contaminate product within the facility, causing a halt on production, and/or a potential product recall. This can incur unexpected costs associated with shutdown time and loss of product.
Concrete can be damp: When in a facility with an untreated concrete floor, at times the slab can feel slightly wet or damp to touch. This is due to moisture within the concrete that can eventually work its way up to the surface of the slab. When this happens, items that are placed on top of the floor can be damaged by trapped moisture above the slab and below the object. When this happens, if a product is not protected properly, it can be damaged.
Concrete is dark and unreflective: An untreated concrete slab can often make a room feel dark and it does not reflect lighting within the room. This can result in the need for extra lights and electricity to properly grow cannabis.
Concrete lacks texture: When working in areas where water and other liquids can fall to the ground and accumulate, flooring with traction can play a key role in helping aid against slip and fall incidents. Untreated concrete typically does not provide sufficient texture and can become very slippery when wet.
The Benefits of Bare Concrete Flooring
While the previously mentioned risks can be associated with bare concrete flooring, there is an upside to the situation! Concrete is the perfect substrate for adding a coating that is built to withstand the industry’s demands.
With the application of a fluid-applied or resinous floor coating, the risks of bare concrete flooring can be mitigated. There are a variety of resin and fluid-based coating systems that can be applied, such as:
Epoxy and Urethane Systems
Urethane Mortar Systems
Decorative Quartz Systems
Decorative Flake Systems
These durable coatings have numerous benefits and can offer:
Protection against the proliferation bacteria and other pathogens: Unlike porous concrete, a smooth and virtually seamless floor coating eliminates the little crevices where pathogens can grow. This in turn helps aid against the growth of bacteria, keeping hygiene standards at the forefront and grow rooms in full operations.
Protection against moisture damage: As moisture within the concrete can move upward to the surface of the slab, there are moisture mitigation coating systems, that keep it trapped below the surface, thus helping toprotect items placed on the floor.
Brighter spaces and light reflection: Installing a floor coating that is light in color, such as white or light gray, can help brighten any space. The benefits of this are twofold: First, it can help with visibility, helping employees navigate the space safely. Secondly, light reflectivity of the flooring improves lighting efficiency, resulting in fewer light fixtures and smaller electric costs.
Texture options to help aid against slip and fall incidents: Floor coating systems can offer a variety of texture options−from light grit to heavy grit−depending on how much accumulated water and foot traffic the area receives. Without additional texture in wet areas, slip and fall incidents and injuries are inevitable.
A wide range of colors and decorative systems: These coating systems can be designed to match the aesthetics of the building or corporate colors. Some manufacturers even offer color matching upon request. When it comes to colors, the options are virtually endless.
Choosing the Right Flooring: Considering Bare Concrete
Choosing the right flooring for a cannabis greenhouse or processing facility requires important consideration as every grow room and greenhouse is different. Bare concrete is a popular flooring option for manufacturing and processing facilities across industries, however, as discussed, it can pose unique challenges due to its innate nature. That said, by taking the right steps to ensure that the concrete substrate is properly sealed, it can then be an effective and hygienic flooring option, offering high durability and a longer life cycle.
In 1887, Julius Petri invented a couple of glass dishes, designed to grow bacteria in a reproducible, consistent environment. The Petri dish, as it came to be known, birthed the scientific practice of agar cultures, allowing scientists to study bacteria and viruses. The field of microbiology was able to flourish with this handy new tool. The Petri dish, along with advancements in our understanding of microbiology, later developed into the modern field of microbial testing, allowing scientists to understand and measure microbial colonies to detect harmful pathogens in our food and water, like E. coli and Salmonella, for example.
The global food supply chain moves much faster today than it did in the late 19th century. According to Milan Patel, CEO of PathogenDx, this calls for something a little quicker. “Traditional microbial testing is tedious and lengthy,” says Patel. “We need 21st century pathogen detection solutions.”
Milan Patel first joined the parent company of PathogenDx back in 2012, when they were more focused on clinical diagnostics. “The company was predominantly built on grant funding [a $12 million grant from the National Institute of Health] and focused on a niche market that was very specialized and small in terms of market size and opportunity,” says Patel. “I realized that the technology had a much greater opportunity in a larger market.”
He thought that other markets could benefit from that technology greatly, so the parent company licensed the technology and that is how PathogenDx was formed. Him and his team wanted to bring the product to market without having to obtain FDA regulatory approval, so they looked to the cannabis market. “What we realized was we were solving a ‘massive’ bottleneck issue where the microbial test was the ‘longest test’ out of all the tests required in that industry, taking 3-6 days,” says Patel. “We ultimately realized that this challenge was endemic in every market – food, agriculture, water, etc. – and that the world was using a 140-year-old solution in the form of petri dish testing for microbial organisms to address challenges of industries and markets demanding faster turnaround of results, better accuracy, and lower cost- and that is the technology PathogenDx has invented and developed.”
While originally a spinoff technology designed for clinical diagnostics, they deployed the technology in cannabis testing labs early on. The purpose was to simplify the process of testing in an easy approach, with an ultra-low cost and higher throughput. Their technology delivers microbial results in less than 6 hours compared to 24-36 hours for next best option.
Out of all the tests performed in a licensed cannabis testing laboratory, microbial tests are the longest, sometimes taking up to a few days. “Other tests in the laboratory can usually be done in 2-4 hours, so growers would never get their microbial testing results on time,” says Patel. “We developed this technology that gets results in 6 hours. The FDA has never seen something like this. It is a very disruptive technology.”
When it comes to microbial contamination, timing is everything. “By the time Petri dish results are in, the supply chain is already in motion and products are moving downstream to distributors and retailers,” Patel says. “With a 6-hour turnaround time, we can identify where exactly in the supply chain contaminant is occurring and spreading.”
The technology is easy to use for a lab technician, which allows for a standard process on one platform that is accurate, consistent and reproduceable. The technology can deliver results with essentially just 12 steps:
Take 1 gram of cannabis flower or non-flower sample. Or take environmental swab
Drop sample in solution. Swab should already be in solution
Transfer 1ml of solution into 1.5ml tube
Conduct two 3-minute centrifugation steps to separate leaf material, free-floating DNA and create a small pellet with live cells
Conduct cell lysis by adding digestion buffer to sample on heat blocks for 1 hour
Conduct Loci enhancement PCR of sample for 1 hour
Conduct Labelling PCR which essentially attaches a fluorescent tag on the analyte DNA for 1 hour
Pipette into the Multiplex microarray well where hybridization of sample to probes for 30 minutes
Conduct wash cycle for 15 minutes
Dry and image the slide in imager
The imager will create a TIFF file where software will analyze and deliver results and a report
Their DetectX product can test for a number of pathogens in parallel in the same sample at the same time down to 1 colony forming unit (CFU) per gram. For bacteria, the bacterial kit can detect E. coli, E. coli/Shigella spp., Salmonella enterica, Listeria and Staph aureus, Stec 1 and Stec 2 E.coli. For yeast and mold, the fungal kit can test for Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus.
Their QuantX is the world’s first and only multiplex quantification microarray product that can quantify the microbial contamination load for key organisms such as total aerobic bacteria, total yeast & mold, bile tolerant gram negative, total coliform and total Enterobacteriaceae over a dynamic range from 100 CFU/mL up to 1,000,000 CFU/mL.
Not all of the PathogenDx technology is designed for just microbial testing of cannabis or food products. Their EnviroX technology is designed to help growers, processors or producers across any industry identify areas of microbial contamination, being used as a tool for quality assurance and hazard analysis. They conducted industry-wide surveys of the pathogens that are creating problems for cultivators and came up with a list of more than 50 bacterial and fungal pathogens that the EnviroX assay can test for to help growers identify contamination hotspots in their facilities.
Using the EnviroX assay, growers can swab surfaces like vents, fans, racks, workbenches and other potential areas of contamination where plants come in contact. This helps growers identify potential areas of contamination and remediate those locations. Patel says the tool could help growers employ more efficient standard operating procedures with sanitation and sterilization, reducing the facility’s incidence of pathogens winding up on crops, as well as reduction in use of pesticides and fungicides on the product.
Deploying this technology in the cannabis industry allowed Milan Patel and the PathogenDx team to bring something new to the world of microbial testing. Their products are now in more than 90 laboratories throughout the country. The success of this technology provides another shining example of how the cannabis market produces innovative and disruptive ideas that have a major impact on the world, far beyond cannabis itself.
EVIO Labs Florida received their ISO 17025:2005 accreditation in February of 2018. Last week, EVIO Labs Florida announced via a press release that they completed their ISO 17025:2017 accreditation and received a certification from AOAC International. The accreditation helped them to further expand their testing scope to shelf life and stability testing, the ability to detect harmful bacteria and calculate degradation in samples.
The certification that they received from AOAC helps verify their ability to conduct accurate and fair 3rd party testing, meeting Florida’s requirements for the market. Back when the laboratory first started in 2017, there were no requirements for lab testing cannabis products under Florida’s regulations.
Upon expanding to their Gainesville location in November last year and getting accredited to ISO 17025:2017 last week, EVIO Labs Florida expects the new location to be compliant and operational by April 2019, in preparation for the state’s new regulations. “Our team has worked diligently to maintain our stance as the Gold Standard in Cannabis Testing,” says Chris Martinez, co-founder and president of EVIO Lab Florida. “The ability to obtain the recent ISO 17025:2017 and AOAC certification is a testament to our dedication in maintaining public safety and product integrity in an ever-growing industry.”
Martinez is also presenting during the 2ndAnnual Cannabis Labs Virtual Conference on April 2, where he will discuss how EVIO Labs Florida began as a laboratory and how they were able to expand to a second location and grow their market presence in Florida. Click here to register for his talk.
The cannabis industry is probably more informed about patients and consumers of their products than the general food industry. In addition to routine illness and stress in the population, cannabis consumers are fighting cancer, HIV/AIDS and other immune disorders. Consumers who are already ill are immunocompromised. Transplant recipients purposely have their immune system suppressed in the process of a successful transplant. These consumers have pre-existing conditions where the immune system is weakened. If the immunocompromised consumer is exposed to viral or bacterial pathogens through cannabis products, the consumer is more likely to suffer from a viral infection or foodborne illness as a secondary illness to the primary illness. In the case of consumers with weakened immune systems, it could literally kill them.Bacteria, yeast, and mold are present in all environments.
The cannabis industry shoulders great responsibility in both the medical and adult use markets. In addition to avoiding chemical hazards and determining the potency of the product, the cannabis industry must manufacture products safe for consumption. There are three ways to control pathogens and ensure a safe product: prevent them from entering, kill them and control their growth.
Prevent microorganisms from getting in
Think about everything that is outdoors that will physically come in a door to your facility. Control the quality of ingredients, packaging, equipment lubricants, cleaning agents and sanitizers. Monitor employee hygiene. Next, you control everything within your walls: employees, materials, supplies, equipment and the environment. You control receiving, employee entrance, storage, manufacturing, packaging and distribution. At every step in the process, your job is to prevent the transfer of pathogens into the product from these sources.
The combination of raw materials to manufacture your product is likely to include naturally occurring pathogens. Traditional heat methods like roasting and baking will kill most pathogens. Remember, sterility is not the goal. The concern is that a manufacturer uses heat to achieve organoleptic qualities like color and texture, but the combination of time and temperature may not achieve safety. It is only with a validated process that safety is confirmed. If we model safety after what is required of food manufacturers by the Food and Drug Administration, validation of processes that control pathogens is required. In addition to traditional heat methods, non-thermal methods for control of pathogens includes irradiation and high pressure processing and are appropriate for highly priced goods, e.g. juice. Killing is achieved in the manufacturing environment and on processing equipment surfaces after cleaning and by sanitizing.
If you have done everything reasonable to stop microorganisms from getting in the product and you have a validated step to kill pathogens, you may still have spoilage microorganisms in the product. It is important that all pathogens have been eliminated. Examples of pathogens include Salmonella, pathogenic Escherichia coli, also called Shiga toxin-producing E. coli (STEC) and Listeria monocytogenes. These three common pathogens are easily destroyed by proper heat methods. Despite steps taken to kill pathogens, it is theoretically possible a pathogen is reintroduced after the kill step and before packaging is sealed at very low numbers in the product. Doctors do not know how many cells are required for a consumer to get ill, and the immunocompromised consumer is more susceptible to illness. Lab methods for the three pathogens mentioned are designed to detect very low cell numbers. Packaging and control of growth factors will stop pathogens from growing in the product, if present.
Control the growth of microorganisms
These growth factors will control the growth of pathogens, and you can use the factors to control spoilage microbes as well. To grow, microbes need the same things we do: a comfortable temperature, water, nutrients (food), oxygen, and a comfortable level of acid. In the lab, we want to find the pathogen, so we optimize these factors for growth. When you control growth in your product, one hurdle may be enough to stop growth; sometimes multiple hurdles are needed in combination. Bacteria, yeast, and mold are present in all environments. They are at the bottom of the ocean under pressure. They are in hot springs at the temperature of boiling water. The diversity is immense. Luckily, we can focus on the growth factors for human pathogens, like Salmonella, pathogenic E. coli, and Listeria monocytogenes.
Temperature. Human pathogens prefer to grow at the temperature of the human body. In manufacture, keep the time a product is in the range of 40oF to 140oF as short as possible. You control pathogens when your product is at very hot or very cold temperatures. Once the product cools after a kill step in manufacturing, it is critical to not reintroduce a pathogen from the environment or personnel. Clean equipment and packaging play key roles in preventing re-contamination of the product.
Water. At high temperatures as in baking or roasting, there is killing, but there is also the removal of water. In the drying process that is not at high temperature, water is removed to stop the growth of mold. This one hurdle is all that is needed. Even before mold is controlled, bacterial and yeast growth will stop. Many cannabis candies are safe, because water is not available for pathogen growth. Packaging is key to keep moisture out of the product.
Nutrients. In general, nutrients are going to be available for pathogen growth and cannot be controlled. In most products nutrients cannot be removed, however, recipes can be adjusted. Recipes for processed food add preservatives to control growth. In cannabis as in many plants, there may be natural compounds which act as preservatives.
Oxygen. With the great diversity of bacteria, there are bacteria that require the same oxygen we breathe, and mold only grows in oxygen. There are bacteria that only grow in the absence of oxygen, e.g. the bacteria responsible for botulism. And then there are the bacteria and yeast in between, growing with or without oxygen. Unfortunately, most human pathogens will grow with or without oxygen, but slowly without oxygen. The latter describes the growth of Salmonella, E. coli, and Listeria. While a package seals out air, the growth is very slow. Once a package is opened and the product is exposed to air, growth accelerates.
Acid. Fermented or acidified products have a higher level of acid than non-acid products; the acid acts as a natural preservative. The more acid, the more growth is inhibited. Generally, acid is a hurdle to growth, however and because of diversity, some bacteria prefer acid, like probiotics which are non-pathogenic. Some pathogens, like E. coli, have been found to grow in low acid foods, e.g. juice, even though the preference is for non-acidic environments.
I have been studying microorganisms for over 35 years, and the elusive critters still fascinate me! Here in Microbiology 101, I write about the foundation of knowledge on which all microbiologists build. You may have a general interest in microbiology or have concerns in your operation. By understanding microbiology, you understand the diversity of microorganisms, their source, control of microorganisms and their importance.
The term microbiology covers every living being we cannot see with the naked eye. The smallest microbe is a virus. Next in size are the bacteria, then yeast and mold cells, and the largest microbes are the protozoans. The tiny structure of a virus may be important in the plant pathology of cannabis, but will not grow in concentrates or infused products. A virus is not living, until it storms the gate of a living cell and overtakes the functions within the cell. Viruses are the number one cause of foodborne illness, with the number one virus called Norovirus. Think stomach flu. Think illness on cruise ships. Viruses are a food service problem and can be prevented by requiring employees to report sickness, have good personal hygiene including good hand washing, and, as appropriate, wear gloves. Following Good Manufacturing Practices (GMPs) is critical in preventing the transfer of viruses to a product where the consumer can be infected.
The largest microbial cell is the protozoan. They are of concern in natural water sources, but like viruses, will not grow in cannabis products. Control water quality through GMPs, and you control protozoans. Viruses and protozoans will not be further discussed here. Bacteria, yeast and mold are the focus of further discussion. As a food microbiologist, my typical application of this information is in the manufacturing of food. Because Microbiology 101 is a general article on microbiology, you can apply the information to growing, harvesting, drying, manufacture of infused products and dispensing.
It is not possible to have sterile products. Even the canning process of high temperature for an extended time allows the survival of resistant bacterial spores. Astronauts take dehydrated food into space, and soldiers receive MREs; both still contain microbes. Sterility is never the goal. So, what is normal? Even with the highest standards, it is normal to have microbes in your products. Your goal is to eliminate illness-causing microorganisms, i.e. pathogens. Along the way, you will decrease spoilage microbes too, making a product with higher quality.
Yeast and mold were discussed on CIJ in a previous article, Total Yeast & Mold Count: What Cultivators & Business Owners Need to Know. Fuzzy mold seen on the top of food left in the refrigerator too long is a quality issue, not a safety issue. Mold growth is a problem on damaged cannabis plants or cuttings and may produce mycotoxin, a toxic chemical hazard. Following Good Agricultural Practices (GAPs) will control mold growth. Once the plant is properly dried, mold will not grow and produce toxin. Proper growing, handling and drying prevents mycotoxins. Like mold, growth of yeast is a quality issue, not a safety issue. As yeast grow, they produce acid, alcohol and carbon dioxide gas. While these fermentation products are unwanted, they are not injurious. I am aware that some states require cannabis-infused products to be alcohol-free, but that is not a safety issue discussed here.
What are the sources of microorganisms?
People. Employees who harvest cannabis may transfer microorganisms to the plant. Later, employees may be the source of microbes at the steps of trimming, drying, transfer or portioning, extract processing, infused product manufacture and packaging.
Ingredients, Supplies and Materials. Anything you purchase may be a source of microorganisms. Procure quality merchandise. Remember the saying, “you get what you pay for.”
Environment. Starting with the outdoors, microbes come from wind, soil, pests, bird droppings and water. When plants are harvested outdoors or indoors, microbes come from the tools and bins. Maintain clean growing and harvesting tools in good working condition to minimize contamination with microbes. For any processing, microbes come from air currents, use of water, and all surfaces in the processing environment from dripping overhead pipes to floor drains and everything in between.
In Part 2 I will continue to discuss the diversity of microorganisms, and future articles will cover Hazard Analysis and Critical Control Points (HACCP) and food safety in more detail. What concerns do you have at each step of operations? Are you confident in your employees and their handling of the product? As each state works to ensure public health, cannabis-infused products will receive the same, if not more, scrutiny as non-cannabis food and beverages. With an understanding and control of pathogens, you can focus on providing your customers with your highest quality product.
Editor’s note: This article should serve as a foundation of knowledge for yeast and mold in cannabis. Beginning in January 2018, we will publish a series of articles focused entirely on yeast and mold, discussing topics such as TYMC testing, preventing yeast and mold in cultivation and treatment methods to reduce yeast and mold.
Cannabis stakeholders, including cultivators, extractors, brokers, distributors and consumers, have been active in the shadows for decades. With the legalization of recreational adult use in several states, and more on the way, safety of the distributed product is one of the main concerns for regulators and the public. Currently, Colorado1, Nevada and Canada2 require total yeast and mold count (TYMC) compliance testing to evaluate whether or not cannabis is safe for human consumption. As the cannabis industry matures, it is likely that TYMC or other stringent testing for yeast and mold will be adopted in the increasingly regulated medical and recreational markets.
The goal of this article is to provide general information on yeast and mold, and to explain why TYMC is an important indicator in determining cannabis safety.
Yeast & Mold
Yeast and mold are members of the fungi family. Fungus, widespread in nature, can be found in the air, water, soil, vegetation and in decaying matter. The types of fungus found in different geographic regions vary based upon humidity, soil and other environmental conditions. In general, fungi can grow in a wide range of pH environments and temperatures, and can survive in harsh conditions that bacteria cannot. They are not able to produce their own food like plants, and survive by breaking down material from their surroundings into nutrients. Mold cannot thrive in an environment with limited oxygen, while yeast is able to grow with or without oxygen. Most molds, if grown for a long enough period, can be detected visually, while yeast growth is usually detected by off-flavor and fermentation.
Due to their versatility, it is rare to find a place or surface that is naturally free of fungi or their spores. Damp conditions, poor air quality and darker areas are inviting environments for yeast and mold growth.
Cannabis plants are grown in both indoor and outdoor conditions. Plants grown outdoors are exposed to wider ranges and larger populations of fungal species compared to indoor plants. However, factors such as improper watering, the type of soil and fertilizer and poor air circulation can all increase the chance of mold growth in indoor environments. Moreover, secondary contamination is a prevalent risk from human handling during harvest and trimming for both indoor and outdoor-grown cannabis. If humidity and temperature levels of drying and curing rooms are not carefully controlled, the final product could also easily develop fungi or their growth by-product.
What is TYMC?
TYMC, or total yeast and mold count, is the number of colony forming units present per gram of product (CFU/g). A colony forming unit is the scientific means of counting and reporting the population of live bacteria or yeast and mold in a product. To determine the count, the cannabis sample is plated on a petri dish which is then incubated at a specific temperature for three to five days. During this time, the yeast and mold present will grow and reproduce. Each colony, which represents an individual or a group of yeast and mold, produces one spot on the petri dish. Each spot is considered one colony forming unit.
Why is TYMC Measured?
TYMC is an indicator of the overall cleanliness of the product’s life cycle: growing environment, processing conditions, material handling and storage facilities. Mold by itself is not considered “bad,” but having a high mold count, as measured by TYMC, is alarming and could be detrimental to both consumers and cultivators.
The vast majority of mold and yeast present in the environment are indeed harmless, and even useful to humans. Some fungi are used commercially in production of fermented food, industrial alcohol, biodegradation of waste material and the production of antibiotics and enzymes, such as penicillin and proteases. However, certain fungi cause food spoilage and the production of mycotoxin, a fungal growth by-product that is toxic to humans and animals. Humans absorb mycotoxins through inhalation, skin contact and ingestion. Unfortunately, mycotoxins are very stable and withstand both freezing and cooking temperatures. One way to reduce mycotoxin levels in a product is to have a low TYMC.
Yeast and mold have been found to be prevalent in cannabis in both current and previous case studies. In a 2017 UC Davis study, 20 marijuana samples obtained from Northern California dispensaries were found to contain several yeast and mold species, including Cryptococcus, Mucor, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus.3 The same results were reported in 1983, when marijuana samples collected from 14 cannabis smokers were analyzed. All of the above mold species in the 2017 study were present in 13 out of 14 marijuana samples.4
Aspergillus species niger, flavus, and fumigatus are known for aflatoxin production, a type of dangerous mycotoxin that can be lethal.5 Once a patient smokes and/or ingests cannabis with mold, the toxins and/or spores can thrive inside the lungs and body.6, 7 There are documented fatalities and complications in immunocompromised patients smoking cannabis with mold, including patients with HIV and other autoimmune diseases, as well as the elderly.8, 9, 10, 11
For this reason, regulations exist to limit the allowable TYMC counts for purposes of protecting consumer safety. At the time of writing this article, the acceptable limit for TYMC in cannabis plant material in Colorado, Nevada and Canada is ≤10,000 CFU/g. Washington state requires a mycotoxin test.12 California is looking into testing for specific Aspergillus species as a part of their requirement. As the cannabis industry continues to grow and advance, it is likely that additional states will adopt some form of TYMC testing into their regulatory testing requirements.
Centre for Disease control and prevention. 2004 Outbreak of Aflatoxin Poisoning – Eastern and central provinces, Kenya, Jan – July 2004. Morbidity and mortality weekly report.. Sep 3, 2004: 53(34): 790-793
Cescon DW, Page AV, Richardson S, Moore MJ, Boerner S, Gold WL. 2008. Invasive pulmonary Aspergillosis associated with marijuana use in a man with colorectal cancer. Diagnosis in Oncology. 26(13): 2214-2215.
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Hazard analysis and critical control points (HACCP) is a robust management system that identifies and addresses any risk to safety throughout production. Originally designed for food safety through the entire supply chain, the risk assessment scheme can ensure extra steps are taken to prevent contamination.
The FDA as well as the Food Safety and Inspection Service currently require HACCP plans in a variety of food markets, including high-risk foods like poultry that are particularly susceptible to pathogenic contamination. As California and other states develop and implement regulations with rigorous safety requirements, cannabis cultivators, extractors and infused product manufacturers can look to HACCP for guidance on bolstering their quality controls. Wikipedia actually has a very helpful summary of the terms referenced and discussed here.
The HACCP system consists of six steps, the first of which being a hazard analysis. For Dr. Markus Roggen, vice president of extraction at Outco, a medical cannabis producer in Southern California, one of their hazard analyses takes place at the drying and curing stage. “When we get our flower from harvest, we have to think about the drying and curing process, where mold and bacteria can spoil our harvest,” says Dr. Roggen. “That is the hazard we have to deal with.” So for Dr. Roggen and his team, the hazard they identified is the potential for mold and bacteria growth during the drying and curing process.
The next step in the HACCP system is to identify a critical control point. “Correct drying of the flower will prevent any contamination from mold or bacteria, which is a control point identified,” says Dr. Roggen. “We also have to prevent contamination from the staff; it has to be the correct environment for the process.” That might include things like wearing gloves, protective clothing and hand washing. Once a control point is identified, the third step in the process is to develop a critical limit for those control points.
A critical limit for any given control point could be a maximum or minimum threshold before contamination is possible, reducing the hazard’s risk. “When we establish the critical limit, we know that water activity below 0.65 will prevent any mold growth so that is our critical limit, we have to reach that number,” says Dr. Roggen. The fourth step is monitoring critical control points. For food manufacturers and processors, they are required to identify how they monitor those control points in a written HACCP plan. For Dr. Roggen’s team, this means using a water activity meter. “If we establish the critical control point monitoring, water activity is taken throughout the drying process, as well as before and after the cure,” says Dr. Roggen. “As long as we get to that number quickly and stay below that number, we can control that point and prevent mold and bacteria growth.”
When monitoring is established and if the critical limit is ever exceeded, there needs to be a corrective action, which is the fifth step in a HACCP plan. In Dr. Roggen’s case, that would mean they need a corrective action ready for when water activity goes above 0.65. “If we don’t have the right water activity, we just continue drying, so this example is pretty simple,” says Dr. Roggen. “Normal harvest is 7 days drying, if it is not dry enough, we take longer to prevent mold or bacteria growth.”
The sixth step is establishing procedures to ensure the whole system works. In food safety, this often means requiring process validation. “We have to double check that our procedure and protocols work,” says Dr. Roggen. “Checking for water activity is only a passive way of testing it, so we send our material to an outside testing lab to check for mold or bacteria so that if our protocols don’t work, we can catch those problems in the data and correct them.” They introduced weekly meetings where the extraction and cultivation teams get together to discuss the processes. Dr. Roggen says those meetings have been one of the most effective tools in the entire system.
The final step in the process is to keep records. This can be as simple as keeping a written HACCP plan on hand, but should include keeping data logs and documenting procedures throughout production. For Dr. Roggen’s team, they log drying times, product weight and lab tests for every batch. Using all of those steps, Dr. Roggen and his team might continue to update their HACCP plans when they encounter a newly identified hazard. While this example is simplistic, the conceptual framework of a HACCP plan can help detect and solve much more complex problems. For another example, Dr. Roggen takes us into his extraction process.
Dr. Roggen’s team, on the extraction side of the business, uses a HACCP plan not just for preventing contamination, but for protecting worker safety as well. “We are always thinking about making the best product, but I have to look out for my team,” says Dr. Roggen. “The health risk to staff in extraction processes is absolutely a hazard.” They use carbon dioxide to extract oil, which carries a good deal of risks as well. “So when we look at our critical control points we need to regularly maintain and clean the extractor and we schedule for that,” says Dr. Roggen.
“My team needs respirators, protective clothing, eyewear and gloves to prevent contamination of material, but also to protect the worker from solvents, machine oil and CO2 in the room.” That health risk means they try and stay under legal limits set by the government, which is a critical limit of 3,000 ppm of carbon dioxide in the environment. “We monitor the CO2 levels with our instruments and that is particularly important whenever the extractor is opened.” Other than when it is being opened, Dr. Roggen, notes, the extractor stays locked, which is an important worker safety protocol.
The obvious corrective action for them is to have workers leave the room whenever carbon dioxide levels exceed that critical limit. “We just wait until the levels are back to normal and then continue operation,” says Dr. Roggen. “We updated our ventilation system, but if it still happens they leave the room.” They utilize a sort of double check here- the buddy system. “I took these rules from the chemistry lab; we always have two operators working on the machine on the same time, never anyone working alone.” That buddy check also requires they check each other for protective gear. “Just like in rock climbing or mountain biking, it is important to make sure your partner is safe.” He says they don’t keep records for employees wearing protective gear, but they do have an incident report system. “If any sort of incident takes place, we look at what happened, how could we have prevented it and what we could change,” says Dr. Roggen.
He says they have been utilizing some of these principles for a while; it just wasn’t until recently that they started thinking in terms of the HACCP conceptual framework. While some of those steps in the process seem obvious, and it is very likely that many cannabis processors already utilize them in their standard operating procedures and quality controls, utilizing the HACCP scheme can help provide structure and additional safeguards in production.
The modern chemical agricultural approach is based on the assumption that chemical science has discovered all facets of plant nutritional requirements. It is clear that the traditional NPK approach to plant/soil systems has its limitations, both from an ecological perspective and in terms of its ability to create nutrient-dense food.
Soil and plant systems have existed together for millions of years and have evolved the capacity to coexist in a way that is mutually beneficial. Plants have been fed and evolved with these biological and environmental stimuli over millennia.
Looking to the geologic record for evidence, we can see that it shows that invertebrates, fungi and early vascular plants appeared on land roughly 400 million years ago, the first seed bearing plants about 360 million years ago and the first flowering plants 130 million years ago. What does this mean? The soil food web has been in existence for millions of years and significant evidence exists that plants and soil biology have co-evolved together for millennia.
Between mineral rich soils and the soil food web, this natural system has been able to create and provide significant plant available nutrients, certainly enough to facilitate the successful life cycle of many species. Clearly from an evolutionary context this system has been able to facilitate maximum genetic expression and the ongoing evolution of biologic species.
In the not-too-distant past, agricultural fertilization practices were based on the existence of a diversity of plant and animal byproducts, animal manures, green manures, etc. These were reintroduced to the system and combined with the appropriate biologic populations, resulting in the decomposition of these organic material inputs and their conversion into plant-available nutrients.
An overview of traditional farming practices provides substantial evidence that farming has been occurring for at least 10,000 years. Why, with such a long history of symbiotic interactions between biologic species, are we now witnessing the mass deterioration of arable land, and agricultural commodities containing lower nutritional value?
An interesting common question among the conventional farming community, when the topic of organics or sustainability comes up, is “how are you going to feed the world?” Well that goal certainly will not be well served by the development of shelf stable, but low nutrient-dense foods. A greater volume of low nutrient-value foods certainly does not seem like a winning approach. Supporting agricultural systems that encourage the development of sustainable systems via locally produced, nutrient-dense food is a good start.
And the same holds true for cannabis. In fact, the parallels between the production of high quality nutrient dense foods and high quality cannabis products are quite significant.
Nutrient density in crops results from balanced, mineral rich soils, and a diversity of organic materials and biologic life, these elements provide the framework to facilitate the creation of a highly functional, biologic nutrient cycling system. A highly functional soil system results in more nutrient-dense crops, which contain measurably larger quantities of different phytonutrients, vitamins, minerals, flavonoids, and terpenes as compared to a system operating at a lower level of biologic efficiency.
Benefits that have been observed from nutrient-dense crops are: more pest and disease resistance in the vegetative and fruiting stages, greater yield, more complex and intense flavors and a longer shelf life.
Ultimately advancement in any cultivation system means finding and defining limiting factors in the given system. The objective should be ensuring the maximum biologic vitality of the components of said system and its outputs. Practically speaking, in order to enable the full genetic potential of biologic species, this means identifying and working toward the removal of limiting factors. Minimizing or entirely alleviating the factors that limit maximum plant growth will undoubtedly net positive gains and must be an integral component to any sustainable cultivation strategy.
The Earth has provided us with a highly successful, multi-million-year-old biologic system, capable of providing abundant plant available nutrients on demand, a dynamic which must be integral to appropriate and intelligent systems design.
In the pursuit of sustainability, perhaps it is time to return to our roots and begin to pursue dynamics that are mutually beneficial to all forms of biologic life.
In the next article, we will take a step back from viewing sustainability through the lens of soil and plant specific cultivation methodologies, and focus on the broader context of sustainability in cultivation systems. We will look at sustainability from the context of operational efficiency, and provide a case study from a 400-light commercial indoor cannabis operation. The case study will provide evidence that, in order to achieve higher levels of sustainability, both cultivation strategies and operational efficiency must be factored into the equation. As we will see, true sustainability is created through the efficient design, incorporation, use and management of system elements, all of which can, when appropriately designed, work together to create improved efficiency for the system.
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