By Dr. Nadia Sabeh, Founder/President of Dr. Greenhouse
Controlling the environmental parameters of the indoor farm is essential to managing the productivity and health of your crop.
This presentation will discuss the critical roles that VPD, airflow, CO2, and other parameters play in the dynamic indoor environment, and we will review different systems and strategies you can use to manage them.
A project case study will be presented to demonstrate the costs associated with different climate management (HVAC) alternatives, including first cost, operating cost, maintenance, and crop productivity.
Maintaining an environment that supports cultivation and keeps plants healthy is not an easy task. In cannabis growing, there are a variety of factors that greenhouse managers and personnel must monitor to ensure that their plants are in a healthy environment that fosters growth and development. Temperature, humidity, lighting and CO2 levels are a few of the conditions that need to be tailored to each cannabis greenhouse operation. However, it can be difficult to constantly monitor the status of your equipment and the greenhouse environment, especially after hours or during the off-season.
A remote monitoring system that’s properly selected and installed can help greenhouse managers keep their cannabis plants healthy, multiply their yields and increase return on investment. This type of system also helps operators identify patterns and trends in environmental conditions and get insight into larger issues that can prevent problems before they arise.
Here are some tips on key conditions to monitor and what you need to consider when selecting a monitoring system for your cannabis greenhouse operation:
Temperature plays a crucial role in any cannabis grow operation. The climate in your greenhouse must be warm enough to nurture photosynthesis and the growth of cannabis plants. Setting the incorrect temperature will significantly impact the potential yield of the plant and the rate at which it develops. A temperature too low will slow the growth of the cannabis, but too hot can lead to heat stress for your plants. The ideal temperature for a standard greenhouse is between 70 and 80 degrees Fahrenheit. However, depending on the stage of plant and desired growth densities, the temperature of the greenhouse needs to be adjusted accordingly.
Humidity directly affects plant photosynthesis and transpiration, so controlling humidity is vital in greenhouse growing. The ideal relative humidity (RH) for cannabis growth is around 60%. A low humidity level can cause water to evaporate too quickly for photosynthesis, while a humidity level that is too high can cause poor growth and possible mold and fungal disease. Monitoring the moisture content in the air of your greenhouse will help the plants during the transpiration process, increasing absorption of nutrients and overall health of the cannabis.
Your cannabis may be getting an abundance of natural light during the summer months, but maintaining adequate sunlight during the winter months can be a challenge. As a solution to this, many greenhouse managers equip their facilities with additional lights to supplement natural light during off-seasons or off-hours. To achieve the best possible yield, a cannabis plant in the budding stage should receive twelve hours of light each day, while other stages could require additional lighting. For example, the growth stage could require your cannabis to be exposed to sunlight for up to eighteen hours a day.
Like any other plant, cannabis requires CO2 to breathe. Greenhouse managers must set and monitor the CO2 levels in their facility to make sure that there is an adequate amount for the plants to develop, grow and be healthy. The amount of carbon dioxide required for your cannabis depends of the size of the facility and the amount of light the plants are receiving. However, a standard grow area for cannabis can maintain a CO2 range from 1000 to 1500 parts per million (PPM). A level below that threshold can result in slower growth of the plants, while a level above would lead to unused and wasted CO2.
Irrigation and Soil Moisture
One way to ensure a good yield from your cannabis is to water it regularly and monitor your soil moisture. Overwatering your plants can have the same effect, if not worse, than letting the soil become too dry. Plants’ roots need oxygen to survive, unlike leaves that breathe CO2, and when the soil is waterlogged the roots can’t provide their function. The lack of oxygen interferes with the roots’ nutrient uptake and photosynthesis causing the cannabis plant to wilt. The exact moisture content of the soil depends on the size of your greenhouse, temperature and humidity. Whether you hand water or are using a drip irrigation system, being aware of your soil moisture is vital to the long-term health of your cannabis.
Your greenhouse environment should mimic the ideal conditions in which cannabis plants flourish. With an indoor facility, you have the ability to control air circulation by venting hot air out and blowing fresh air in. Creating a circulation of air inside your greenhouse will increase your cannabis plant’s growth speed and yield. Additionally, an exhaust system helps control the temperature and humidity, while also preventing the invasion of mold and pests that thrive in hot, stagnant air.
When growing something of value, like cannabis, there will always be a threat of intruders. Whether your greenhouse is in a populated area or around hungry wildlife, any intruder could be detrimental to your overall yields and profit. Remote monitoring systems can give you peace of mind and instantly alert you when there is an unwanted presence in your greenhouse.
Knowing all the possible threats to your cannabis greenhouse helps you evaluate your specific needs, and ultimately identify the proper remote monitoring system.
Selecting the Right Monitoring System
Other factors to consider when choosing a monitoring system right for your operation include:
Base unit and sensors
Wireless or hardwired sensors
Communications to your site (Phone, cellular, Wi-Fi, etc.)
Programming and status checks
Return on investment
Base Units and Sensors
Each condition in your greenhouse that you want to monitor requires its own input on the base unit of the monitoring system. You must match your needs with the number of inputs available. A good fit for a smaller cannabis greenhouse may be a lower-cost, non-expandable monitoring system. However, larger facilities have many monitoring points and more people to alert when there’s a problem. If your cannabis operation is poised for growth, purchasing an expandable system could add value to the initial purchase because you wouldn’t have to replace your entire system in the future.
Your monitoring system should also have an internal rechargeable battery backup to ensure continuous monitoring and alerts in the event of a power outage. It is also recommended to have each base unit in a sheltered enclosure to protect it from moisture, dirt and other hazards.
Placement of sensors is also crucial. For example, temperature sensors in your greenhouse should be placed throughout the facility. They should be next to your thermostat and in the center of your greenhouse, preferably away from direct sunlight.
Wireless or Hardwired Sensors
Remote monitoring systems offer the option to have sensors hardwired directly to the base unit or sensors wirelessly connected. A hardwired monitoring system connects the sensors to the base device with wires. Generally, trenching long distances for wires is time consuming and costly. So alternatively, a wireless system uses built-in radio transmitters to communicate with the base unit. Some monitoring systems can accommodate a combination of hardwired and wireless sensors.
Communications to Your Site
Monitoring devices that use cellular communications must be registered on a wireless network (like Verizon or AT&T) before you can send or receive messages. Because cellular devices perform all communications over a wireless network, it is important that there be sufficient signal strength at the greenhouse. It is a good idea to check the signal quality in the area before purchasing a cellular product. If the cellular network has less than desirable coverage, it is possible to install an external antenna to help increase cellular signal.
When monitoring systems identify a change in status, they immediately send alerts to people on the contact list. If you don’t want all of your personnel to receive notifications at the same time, certain devices can be programmed to send alerts in a tiered fashion. It is important to consider the reach of the communications, so that you’ll be notified regardless of your locations. Multiple communications methods like phone, email and text provide extra assurance that you’ll get the alert. Also, note of the number of people the system can reach and if the system automatically cycles through the contact list until someone responds. Make sure the system allows for flexible scheduling so that it doesn’t send alarms to off-duty personnel.
Programming and Status Check
If you’re responsible for maintaining a commercial greenhouse facility, you want a system that will provide real-time status of all monitored conditions on demand. There are a few different ways to access your sensor readings. Options include calling to check status, viewing a web page, either on a local network or on the cloud, or accessing the information via an app on your mobile device. With a cloud-based system, the devices supervise themselves. This means if the internet or cellular connection goes down, the device will send an alarm to alert the appropriate personnel.
If you don’t select a cloud-based system, you will be limited to logging in through a local area network, which will allow you to make programming changes, access status conditions and review data logs. If internet connectivity is not available at your location, you will want to choose a cellular or phone system rather than Ethernet-based option.
Data history is valuable in identifying patterns and trends in your cannabis greenhouse conditions. Manually monitoring and recording environmental parameters takes a significant amount of personnel time and detracts from other important workplace demands. However, many monitoring systems automatically save information, recording tens of thousands of data points, dates and times. Cloud-based logging provides an unlimited number of records for users to view, graph, print and export data trends.
Analyzing data samples may lend insight to larger issues and prevent problems before they arise. For example, if the data log shows power fluctuations occurring at a regular time, it could be indicative of a more serious problem. Or, if the data shows signs of a ventilation fan or supplementary lighting beginning to malfunction, they can be repaired or replaced before total failure occurs.
Return On Investment
When deciding how much you should pay for a remote monitoring system, tally up the entire cost, fully installed with additional peripherals and sensors and any labor fees for installation. Then consider the value of your cannabis plant inventory and greenhouse equipment. Finally, factor in the cost of downtime, should an environmental event shut down your operation for a period of time.
Choosing the right greenhouse monitoring system and sensors could mean the difference between life and death for your cannabis plants. Understanding the conditions you need to watch and monitoring systems’ capabilities are they best way to protect your investment.
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.
By Olivia L. Dubreuil, Esq., Brett Giddings 2 Comments
Dear Cannabusiness Community,
You may have read our two recent articles. We received so much positive feedback that Aaron Biros (editor-in-chief of Cannabis Industry Journal) has invited us to continue with our own column at CannabisIndustryJournal.com. We are very happy to launch this column, and we thought we would take this opportunity to introduce our project, our vision and ourselves so you can understand where we are coming from when you read this series of articles.
Brett and I both have a background in business sustainability and corporate responsibility. We both have backgrounds in management consulting, with a specific expertise in sustainability issues along the supply chain. We have been working together for almost nine months now on sustainability issues in the Bay Area. In May, we started to get interested in sustainability in the cannabis industry and before we knew it we were diving deep into research relating to the environmental, social and ethical impacts of the legal cannabis industry. It was actually difficult to find a lot of information, as the reign of prohibition still very much influences what is available.
In June, we attended the National Cannabis Industry Association’s conference in Oakland to open up the conversation with cannabis industry players and to find out about people’s attitudes and approach to sustainability. The results were overwhelmingly positive. Not only were we encouraged to launch a project, but also excited to discover that many of the speakers presenting at the conference referenced sustainability in one way or another when they talked about environmental impact awareness, social justice, ethics or about staying competitive when “big business” enters the market.
What started out as a side project quickly became the center of focus this summer when we decided to incorporate Project Polaris, a California non-profit, to deliver sustainability knowledge and expertise to the cannabis industry.
Our thinking is as follows:
Thinking about sustainability, means thinking strategically about business. As we forge a new and upcoming industry, let’s seize the opportunity to make it a sustainability-focused one! Let’s create generally accepted industry principles that fosters a positive image of the industry and teaches newcomers about best environmental and social practices. Let’s create a voluntary and industry-led socially responsible code of conduct for cannabis business owners and suppliers, helping the regulators, as they will be drafting all of the future regulations of the legalized cannabis market. Let’s do more research on the market and the consumer. Let’s develop clean and green alternatives to dirty processes or practices. Let’s elevate the discussion and create a model industry, one where short-term, large-scale, quality-lowering corporate interests are kept at bay.
With this vision in mind, we created Project Polaris because we believe that this is a real opportunity for the industry to be a role model for other industries (and educate legislators as well as drive public opinion in those states that are still under prohibition laws). We believe there is a real economic opportunity for those businesses that understand how to embed sustainability properly within their business model. Because we know that sustainability influences legislators in a positive way because it sheds a positive light on businesses.
In the upcoming months, we will continue to research and report on sustainability-related issues facing the cannabis industry, such as packaging, edibles, “organic” in cannabis, butane extraction versus CO2 extraction and so on. We also welcome questions from our readers. If you have a question, please post it in the comments section below.
We will also take this opportunity to call out to cannabis industry organizations, cannabis businesses, or cannabis related services and product suppliers to get in touch with us if they wish to find out how to integrate sustainability more concretely into their action plan. We are not planning on doing this alone, we are seeking partners to join us on this journey, and we want to partner with you on your journey to Cannabusiness Sustainability.
PS: We still have one seat open for the board of directors and would love to hear from you if you are interested!
Based in Santa Monica, California, Sagely Naturals was founded in the summer of 2015, with the goal to produce a sustainably sourced, topical CBD cream with no psychoactive effects to treat daily aches and pains. The co-founders, Kerrigan Hanna and Kaley Nichol, have extensive backgrounds in the food service industry, and as a result they pride themselves in quality controls and proper safety procedures. Since the launch of Sagely Naturals, they have been selling their Relief & Recovery Cream online and in a wide variety of retail outlets beyond just cannabis dispensaries. Their ability to distribute outside of dispensaries is due to the fact that the product’s active ingredient, Cannabidiol (CBD), is derived from hemp, instead of cannabis with higher levels of Tetrahydrocannabinol (THC).
Their attention to detail in consistency and quality makes them stand out as cannabis processors, using a contract manufacturer with good manufacturing practices (GMPs) along with the proper standard operating procedures (SOPs) in place. “All of our contract manufacturer’s corrective and preventative actions (CAPAs) are outlined in the company’s SOPs, which are in place for everything including specific manufacturing processes, receiving and shipping materials and testing batches,” says Hanna. “The contract manufacturer also provides certificates of analysis (COAs) for every product they make.” According to Hanna, they exclusively use current GMP-certified facilities. One such SOP lays out the responsibilities for the quality control department in order to release and approve ingredients of their products.
There are some SOPs that could pertain specifically to the processing of hemp or cannabis products, according to Hanna. “Receiving and handling raw materials like hemp, batch coding, the actual formulation and manufacturing process, quality controls and cleaning and sanitation [could be tailored to pertain to cannabis],” says Hanna. Proper SOPs laid out in the manufacturing process include the cleaning and sanitation of machines, as well as adjusting settings, formula ratios and initialing and dating product labels on every batch, among more specific operating procedures.
According to the co-founders, they spent a large amount of time vetting their hemp supplier, making sure they are using cutting-edge technology, growing it sustainably, and adhering to strict SOPs. “The team includes a Ph.D. chemist, who also is a founding member of our supplier and extractor,” says Hanna. “We work with CO2 extraction because we wanted the most control over the compounds that end up in our product. We are able to purposefully choose which cannabinoids end up in our product.” Through supercritical carbon dioxide extraction and post-extraction processing, the team is able to eliminate any trace of THC, guaranteeing the consumers will receive no psychoactive effects.
In looking toward long-term growth, the co-founders emphasize the importance of environmental sustainability. “Having honest ingredients is one of our company missions along with having honest practices,” says Hanna. “None of our ingredients are tested on animals so we are an animal cruelty-free organization.” Their hemp is grown using organic and environmentally friendly practices. “We prioritize using plant-based ingredients, so the formulation of our Relief & Recovery Cream relies on using organic and raw materials—such as essential peppermint and safflower oil.” Companies like Sagely Naturals using contract manufacturers to process hemp could represent the future of the cannabis industry. When safety, sustainability and quality issues come into the spotlight more, so will the need for outlined SOPs, proper documentation and extensive lab testing.
The American Oil Chemists’ Society (AOCS) held its annual conference in Salt Lake City this week, with a track focused on cannabis testing and technology. Cynthia Ludwig, director of technical services at AOCS and member of the advisory panel to The Emerald Test, hosted the two-day event dedicated to all things extraction technology and analytical testing of cannabis.
Highlights in the discussion surrounding extraction technologies for the production of cannabis concentrates included the diversity of concentrate products, solvent selection for different extraction techniques and the need for cleaning validation in extraction equipment. Jerry King, Ph.D., research professor at the University of Arkansas, began the event with a brief history of cannabis processing, describing the physical morphologies in different types of extraction processes.
Michael McCutcheon, research scientist at Eden Labs, laid out a broad comparison of different extraction techniques and solvents in use currently. “Butane is a great solvent; it’s extremely effective at extracting active compounds from cannabis, but it poses considerable health, safety and environmental concerns largely due to its flammability,” says McCutcheon. He noted it is also very difficult to get USP-grade butane solvents so the quality can be lacking. “As a solvent, supercritical carbon dioxide can be better because it is nontoxic, nonflammable, readily available, inexpensive and much safer.” The major benefit of using supercritical carbon dioxide, according to McCutcheon, is its ability for fine-tuning, allowing the extractor to be more selective and produce a wider range of product types. “By changing the temperature or pressure, we can change the density of the solvent and thus the solubility of the many different compounds in cannabis.” He also noted that, supercritical carbon dioxide exerts tremendous pressure, as compared to hydrocarbon solvents, so the extraction equipment needs to be rated to a higher working pressure and is generally more expensive.
John A. Mackay, Ph.D., senior director of strategic technologies at Waters Corporation, believes that cannabis processors using extraction equipment need to implement cleaning SOPs to prevent contamination. “There is currently nothing in the cannabis industry like the FDA CMC draft for the botanical industry,” says Mackay. “If you are giving a child a high-CBD extract and it was produced in equipment that was previously used for another strain that contains other compounds, such as CBG, CBD or even traces of THC extract, there is a high probability that it will still contain these compounds as well as possibly other contaminants unless it was properly cleaned.” Mackay’s discussion highlighted the importance of safety and health for workers throughout the workflow as well as the end consumer.
Jeffrey Raber, Ph.D., chief executive officer of The Werc Shop, examined different testing methodologies for different applications, including potency analyses with liquid chromatography. His presentation was markedly unique in proposing a solution to the currently inconsistent classification system for cannabis strains. “We really do not know what strains cause what physiological responses,” says Raber. “We need a better classification system based on chemical fingerprints, not on baseless names.” Raber suggests using a chemotaxonomic system to identify physiological responses in strains, noting that terpenes could be the key to these responses.
Dylan Wilks, chief scientific officer at Orange Photonics, discussed the various needs in sample preparation for a wide range of products. He focused on sample prep and variation for on-site potency analysis, which could give edibles manufacturers crucial quality assurance tools in process control. Susan Audino, Ph.D., chemist and A2LA assessor, echoed Wilks’ concerns over sample collection methods. “Sampling can be the most critical part of the analysis and the sample size needs to be representative of the batch, which is currently a major issue in the cannabis industry,” says Audino. “I believe that the consumer has a right to know that what they are ingesting is safe.” Many seemed to share her sentiment about the current state of the cannabis testing industry. “Inadequate testing is worse than no testing at all and we need to educate the legislators about the importance of consumer safety.”
46 cannabis laboratories participated in The Emerald Test’s latest round of proficiency testing for potency and residual solvents. Cynthia Ludwig sits on the advisory panel to give direction and industry insights, addressing specific needs for cannabis laboratories. Kirsten Blake, director of sales at Emerald Scientific, believes that proficiency testing is the first step in bringing consistency to cannabis analytics. “The goal is to create some level of industry standards for testing,” says Blake. Participants in the program will be given data sets, judged by a consensus mean, so labs can see their score compared to the rest of the cannabis testing industry. Proficiency tests like The Emerald Test give labs the ability to view how consistent their results are compared to the industry’s results overall. According to Ludwig, the results were pleasantly surprising. “The results were better than expected across the board; the vast majority of labs were within the acceptable range,” says Ludwig. The test is anonymous so individual labs can participate freely.
The AOCS cannabis working groups and expert panels are collaborating with Emerald Scientific to provide data analytics reports compliant with ISO 13528. “In the absence of a federal program, we are trying to provide consistency in cannabis testing to protect consumer safety,” says Ludwig. At the AOCS annual meeting, many echoed those concerns of consumer safety, proposing solutions to the current inconsistencies in testing standards.
It is also important to note that the same is true of carbon dioxide in its natural form on the earth’s atmosphere, it is a gas. It is nonflammable and used in fire extinguishers.
At typical conditions, carbon dioxide in the supercritical range is similar to hexane (C6H14) and ethyl acetate in its solubility characteristics. Propane (C3H8) and butane (C4H10) are gases at normal atmospheric conditions. Both must be manipulated for the extraction of CBDA and CBD. For example, both CO2 and C4H10 must be placed under pressure and then passed through the material to extract the lipophilic terpenes and cannabinoids.
For this short discussion, let’s remove the concern about the different volatilities of the compounds. Hydrocarbons with a spark will be significantly more powerful of an explosion than carbon dioxide (note it could be used to put out the butane fire). The hydrocarbons can be in more configurations and therefore the getting the correct form initially is critical. For example, butane can have all the carbons in a row like a train, or branched like a tree. Those are very different and have different characteristics too. Getting pharmaceutical grade butane is essential to ensure safety. The concern that people have expressed with butane is what is in the other 0.1% for 99.9%. Checking for residual butane is less of a concern than the polyaromatic hydrocarbons in the untested cylinder. Furthermore, in the wrong hands it can be more volatile.
The critical premise that needs to be considered is the final formulation. Is one solvent significantly more applicable than the other? No. They have different characteristics.
Propane is a common solvent in the spices, flavors and fragrances industry. For example, the extraction of lipids and oils from vegetables and the fatty oils from seeds, it would be an advantage to have a solvent that is totally miscible, i.e. will be totally soluble in a fluid. This is similar to the idea of sugar in hot water versus in water in ice. If an example of cardamom were used comparing CO2 and propane (which is similar to butane), the pressure needed for CO2 would be 100 bar, while propane would be only 20 bar. However the increasing the pressure of the propane from 20 to 50 bar at a constant 25 C, also increases the chlorophyll from 3.4 g/g oil to 10.8 g/g oil. Meanwhile with the more finely tunable CO2 from 80 to 100 to 200 the amount of chlorophyll is negligible (0.36 g/g oil) but at 300 bar it dramatically increases to 4.53 g/g oil.
Additionally the CO2 is a better extraction for the terpenes in the cardamom. The beta-pinine, Cineole, linalool, alpha-terpinol and bornelole. The increase in the propane pressure will allow us to increase the yield of the CO2 (Illes, V, et. al. Proceedings of the Fifth Meeting of Supercritical Fluids, Nice, France, Tome 2, 555-560).
This example is the same with the butane and cannabis. Butane is a stronger solvent and if left too long will continue to pull out more and more polar compounds like chlorophyll. With the fine-tuning of CO2, you can eliminate or you can pull out the chlorophyll if you choose the wrong conditions.
So fast extractions are possible with butane but little control of all the material, while CO2 can be tunable and therefore is able to collect all of the same material, just through a segmented process.
Over the next few months, I would like to walk through a series of articles to cover the number of ways to extract potentially pharmaceutically active compounds from cannabis plants. However, in the first article I would like to review concerns being addressed in state regulations: contamination in concentrates with pesticides, mycotoxins, and residual solvents. The next article will cover the most common extraction with two different modes: CO2 versus hydrocarbons.
Currently, there is a lot of focus on the cannabis strain of hemp. This is defined as having less than 0.3% of THC, (the psychoactive compound). To be clear, the science of extraction is eons old, but the current revitalization is due to new scientific inquiry regarding the applications of the cannabis plant.
I am often asked, “What is the ‘best’ extraction for a natural product?” The BEST extraction? The key to this answer is that you must assume unintended consequences until you can prove that they are at least minimized compared to the intended consequences.
I have a suggestion for you to consider and I look forward to your response to it. I also assume the right to adapt and revise it.
Botanical integrity from seed to shelf
Efficacy of the process beyond efficiency, economics, effectiveness
Safety of people and product
Testing for confirmation at each step of process
The hemp industry has changed significantly over the past few years. Just casually flipping through the channels on television, reading a newspaper or magazine, (on any topic – news, business, sports, food and science) and there is some facet of hemp’s value being examined. The reduction of traditional pulmonary intake (smoking) in the legal marketplace can be tracked by sales of these products in the states where it is legal. The balance of ingestion is drastically tipping toward what might still be considered smoking with vaporizer products as well as toward edible consumables. The ingredients in these products come not from just adding the plant to the formulation, but rather a concentrated mixture. This is the difference between adding a raw vanilla and a teaspoon of vanilla extract. The compound getting the most coverage is cannabidiol (CBD), which is the compound derived from cannabidiolic acid (CBDA). The effects of the other compounds in the plant are being studied as well.
Unintended consequences from the concentration – extraction – are something we need to consider seriously as consumers. The labeled use of “natural” is one that is critical, but can be totally nullified by the unintended contamination in the extraction workflow. Years of making sure the hemp adheres to strict growing environment can be destroyed in seconds with the addition of polycyclic aromatic hydrocarbons (PAH’s) by the use of solvent that has these toxic chemicals in them. These come not through intended consequences, but not knowing the stabilizers and other additives in material being added to these previously pure plants.
What if I pour sour milk on a natural granola for breakfast? What if I use water with high lead or contaminated water to pour over natural coffee grind? Not a great way to start the day, but it is no different than using the most premium hemp and unknowingly adding low grade solvents or adding components from cleaning the surfaces of instruments that come in contact with hemp.
Note that, by definition, we are concentrating the material from the hemp plant. From 4,000 grams, we are getting 400 grams of CBDA if it is 10% by weight (and later converted to CBD). That compound is 10 times more concentrated in a solution. What other compounds are now also 10 times or 5 times or 100 times more concentrated? Maybe no “bad” ones, but how do you know that something else is not also in the mixture?
This is illustrated in the filtering of green balls in Figure 1. As the green balls become a greater and greater percentage of the solution, it is possible that other compounds like pesticides are also increasing in percentage of the extraction solution. The solution is more concentrated and “simpler” versus all of the other things in the original mixture.
The simple answer is in the testing of the components. The labeling of major compounds is only the beginning of what is on the label that you read. Heavy metals? PAH’s? Residual solvents? Pesticides? Molds? And a long list of other material that could come into the process after the plant left its pristine organic farm. Many studies can be read about slip agents in bags, contamination from workers in the workflow, and other sources of inconsistency.
There are a significant number of companies that I have seen that take this very seriously. New companies are being formed that have safety of product at the top of the list of importance. They are building facilities that are sterile and putting standard operating procedures in place that continually test the product along every step to ensure that they are in compliance.
Supercritical fluid extraction is GRAS (generally regarded as safe). It is, only as long as the solvent specifications are known, the vendor meets those standards, and the instrument surfaces meet any necessary standards.
Supercritical carbon dioxide is used to clean surfaces of electronics and bones for skin grafts. It is used for the decaffeination of coffee as well as pulling trace amounts of pesticides from soil. It is used to extract antioxidants from krill and the active ingredients from algae as well as oil from core samples deep below the earth. It also extracts the terpenes and CBDA from hemp – as well as possibly anything that has been added to it.
The key take away from this article is to know the BEST extraction.
Botanical integrity from seed to shelf
Efficacy of the process beyond efficiency, economics, effectiveness
Safety of people and product
Testing for confirmation
Taking each of these into consideration will bring the best results for concentrations of hemp products. I hope you can extract the best from your day.
You can adjust all of your cookie settings by navigating the tabs on the left hand side.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
We use tracking pixels that set your arrival time at our website, this is used as part of our anti-spam and security measures. Disabling this tracking pixel would disable some of our security measures, and is therefore considered necessary for the safe operation of the website. This tracking pixel is cleared from your system when you delete files in your history.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
3rd Party Cookies
This website uses Google Analytics to collect anonymous information such as the number of visitors to the site, and the most popular pages.
Keeping this cookie enabled helps us to improve our website.
Please enable Strictly Necessary Cookies first so that we can save your preferences!
We also use a Tracking Beacon from our email services provider Act-On that allows us to track interest in articles and subject areas of interest to our Newsletter Subscribers.
Keeping this beacon enabled helps us in deciding the topics that are of interest to our Newsletter Subscribers.
Please enable Strictly Necessary Cookies first so that we can save your preferences!