Check Out the Cannabis Science and Technology September/October Issue!

Check Out Our Higher Education Supplement!

Read our latest blog on safety, transparency, and accountability in the cannabis industry

How cGMP Compliance Can Tackle Inconsistent Testing

On this episode we are joined by Susan Audino, PhD, founder of S.A. Audino & Associates, LLC, and co-founder of Saturn Scientific, LLC

Ep 23, Part III: Accreditation in the Cannabis Industry with Susan Audino

Share Your Work With Us and Help Educate the Cannabis Industry!

Call For Papers: Cannabis Science and Technology 2024/2025 Issues

In this month’s column, guest contributor, Rob Thomas takes a critical look at the big four heavy metals which are regulated by the vast majority of US states and suggests that there is compelling evidence in the public domain that the panel should be increased because there is not a good understanding of the sources of elemental contaminants in the production of cannabis consumer products. As a result of the inadequate nature of these state-based regulations, consumer safety is most likely being compromised.

 examined the fractured nature of state-based regulations and compared it with the federal limits for pharmaceutical products and dietary supplements. Part II, will take a look at specific examples in the public domain of elemental contamination of cannabis consumer products, which shows that other elements are worthy of consideration and should be a part of the regulatory framework.

Both AOAC International (AOAC) and ASTM International (ASTM) have developed standardized methods for carrying out the measurement of heavy metals in cannabis matrices by inductively coupled plasma mass spectrometry (ICP-MS). The AOAC (OMA 2021.03) surveillance method for the routine monitoring of 12 elements, including lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), antimony (Sb), barium (Ba), chromium (Cr), copper (Cu), nickel (Ni), silver (Ag), selenium (Se), and zinc (Zn) was first published in 2021 (1), while ASTM International's D37 Cannabis Committee (Under D37.03) recently developed a more detailed standardized ICP-MS method (ASTM D8469-22) for up to 23 elemental contaminants in different cannabis matrices in 2023 (2). As part of the ASTM validation procedure, an interlaboratory proficiency testing study was carried out where four volunteer laboratories were asked to test three different samples for a panel of toxic elements based on interest expressed by the cannabis community for safety and regulatory reasons. The three samples were a control plant material, National Institute of Standards and Technology (NIST) 1575a pine needles, together with a National Research Council of Canada (NRC) Hemp 1 and a NIST Hemp 4 reference material (described in NIST CannaQAP Exercise 2 Program) (3). Every test result represents individual determinations, and all participants were instructed to report three replicates for each material. The spike recoveries, precision, bias, reproducibility and uncertainty of the test method was carried out according to Practice E691 defined in ASTM Research Report No. RR:D37-2001 (4). The values obtained by four independent testing laboratories were averaged together with their interlaboratory standard deviations (SD) and compared with the values obtained by the respective standards organizations. 

 shows the full panel of elements for one of the hemp reference materials (NIST 4 CannaQAP material) together with standard deviation (reproducibility) of the results.

It is interesting to note that while only 12 toxic metals were studied in this material by NIST, 11 additional elements have been measured and quantified meaning that if this hemp sample is typical, it contains toxic metals which would escape the scrutiny of most state regulators. However, if there is a positive, it demonstrates how matrix-based reference materials can offer testing labs the flexibility to select the heavy metals that are important in their jurisdiction and in particular to encourage state regulators to expand the panel beyond the big four to those additional metals that are worthy of regulatory oversight. At the time of writing this article, this NIST Hemp 4 reference material is nearing completion. After the CannaQAP Exercise 2 was completed, several modifications were made to the material before it was homogenized and packaged, and as a result, values in this publication will not be the final assigned values. However, the material along with the values in a Reference Material Information Sheet, became available in the summer of 2024 at 

Routine Screening of Commercially Grown Cannabis and Hemp

At an ASTM D37 symposium in October 2023 dedicated to the measurement of contaminants in cannabis and hemp consumer products, compelling data was presented by several researchers which suggested that 15-20 elemental contaminants could be worthy of consideration (5). One of the presentations was by Kaycha Labs (a private laboratory that conducts routine screening of cannabis products in Colorado) in collaboration with researchers at the Colorado School of Public Health, Environmental, and Occupational Health, Center for Health, Work & Environment. The title of their talk, “Preliminary Levels and Distribution of Health-Relevant Heavy Metals in Commercially Grown Cannabis and Hemp,” characterized levels of 20 heavy metals in 60 Colorado market cannabis flower using newly validated laboratory methods. Flower samples were randomized, de-identified and separated by type of grow operation (indoor/outdoor). Additionally, to ensure characterization of those samples that may pose the greatest risk of heavy metal-related health effects, the random sample also included samples of cannabis flower that failed Colorado heavy metal limits for Pb (0.5 ppm), Cd (0.2 ppm), Hg (0.1 ppm), or As (0.2 ppm).

The study was extensive and represented one of the most comprehensive characterizations to date of monitoring a wider panel of elemental contaminants beyond the currently regulated “big four” metals of arsenic, cadmium, lead, and mercury. Moreover, the conclusion of the study was very revealing as evidenced by the following statement (6), “Given the potential for additional accumulation of metals from methods of cannabis consumption, particularly vaping, and the wide range of systemic health impacts associated with heavy metal exposure, further resources should be allocated to considering the expansion of current regulatory requirements of these products. Changes in regulatory testing requirements should be accompanied by investments in public health laboratory infrastructure and workforce investments to support expanded testing.” This study was written up and is a part of the symposium proceedings which is currently moving through the publication process and is expected to be published in the 

There is also a great deal of data in the public domain of specific heavy metals being found not only from the cultivation and growing environment but also in production of cannabis and hemp consumer products related to corrosion of metal-based equipment, metallic components and storage vessels containing metals, that are in contact with liquids, oils and extracts during the cannabinoid manufacturing, production, packaging, and delivery process. For example, lead is one of the most common adulterants because it has been so widely used over the years in our everyday lives including water pipes, paint, gasoline, ceramic glazes, alloys, solders, etc., and is known to cause neurological issues, severe nerve damage, cardiovascular problems, which greatly increase the incidence of certain cancers. There are many cases of lead and other toxic metals finding their way into commercially available cannabinoid consumer products, but let’s take a closer look at some specific cases (7).

Tom Gluodenis PhD, Professor, Dept of Chemistry & Physics, and coworkers at Lincoln University carried out a trace metal profiling study of cannabidiol (CBD) tincture oils which were manufactured by US Hemp Authority certified companies with the expectation that the products would represent the highest quality available (8). 15 samples of CBD tincture oil were purchased, each from a different manufacturer, while two additional purchases for a total of three samples per manufacturer, were made at six month increments so that “lot to lot” variations could be assessed for each manufactured product. In an attempt to minimize experimental variables, each product purchased was a full spectrum tincture oil (containing all cannabinoid extracts including <0.3% tetrahydrocannabinol [THC]). In addition to the “certified samples”, a random sampling of 10 additional products purchased locally at gas stations, smoke shops, and other outlets were analyzed for comparison purposes.

The oils were digested in a mixture of nitric and hydrochloric acid in a microwave digestion oven and analyzed by ICP-MS. Most of the samples were very clean and were below the regulated limits for the four heavy metals required by the state of Pennsylvania. However, four of them contained Pb levels which were all higher than the 0.5 ppm regulatory limit for Pennsylvania. Moreover, the three different lots for one of the “certified samples” and one of the “shop-bought” samples showed significant differences as seen in 

, suggesting that the Pb contamination was variable and predictable and could have been caused by a source of lead in the production process or storage equipment.

Interestingly, the study also confirmed that the two samples were in excess of 100 µg/g (ppm) tin (Sn), which would suggest that tin-based solder was the source of the contamination. This is below the ICH Q3D PDE limit for oral drug products of 600 µg/g. However, it is worth noting that this limit is based on inorganic Sn, whereas Sn toxicity is heavily dependent upon the speciated form. For example, some organotin compounds have been shown to result in renal and neurotoxicity, which is largely due to the lipophilic nature of organotin compounds allowing them to be readily absorbed from the gastrointestinal tract where they can then migrate to other parts of the body (9). However, the form of the tin present in the CBD oils is currently unknown and there have been no known speciation studies conducted to date in these types of samples.

Diane Picket, Chief of Florida Department of Agriculture and Consumer Services Food Safety Lab and co-workers at the Florida Department of Agriculture Consumer Services Food Safety Lab (FDACS) did an exhaustive study of monitoring a group of toxic metals in 208 hemp extract oils (10). The good news was that lead was the only heavy metal that was found in appreciable amounts. 42 of the samples tested positive for Pb, but below the regulatory limit for of 0.5 ppm. However, the bad news is that 10 of the samples exceeded the 0.5 ppm limit, with two of them being over the Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) limit for hazardous waste of 5 ppm (10x regulated limit for Florida [FL]) while one of them was 19 ppm (38x higher than the legal limit). On further investigation of some of the samples being stored in glass bottles they found that the lead levels increased over time, which suggested the Pb was either being leached out of the glass or the ink used for the graduated marks. They haven’t ruled out the borosilicate glass dropper bottles being the culprit because unless it is high purity, some glasses are known to contain transition and heavy metals contaminants from the glass manufacturing process. However, their study is still on-going, but it now seems more than likely that the ink used for the graduated marks is a Pb-based formulation similar to leaded household paints that were eventually banned in the US in 1978.

Metal Dyes Used in Cannabis Rolling Papers

One area that has received little attention is the possible exposure to potentially hazardous levels of toxic elements from cannabis rolling papers. The elemental composition of rolling papers has gone mostly under the radar, with the exceptions of some states that implement regulations only when they are part of a final product such as cannabis pre-rolls. Well, this all may be about to change with a fascinating study in the journal, 

, by researchers at Lake Superior State University (LSSU) entitled, “Elemental Composition of Commercially Available Cannabis Rolling Papers” (11). In this study, the concentrations of 26 elements in commercially available rolling papers are characterized and measured by ICP-MS and Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-ray Spectroscopy (EDXS) to estimate potential maximum exposures limits relative to dosages in drug inhalation products as defined in United States Pharmacopeia (USP) Chapter 232 and ICH Q3D Guidelines. Exposure estimates indicate that the concentrations of several elements, including Ag, Ba, Cr, Cu, molybdenum (Mo), Ni, Sb, titanium (Ti) and vanadium (V), are likely present at elevated quantities in some papers due to product design and manufacturing processes. In particular, Cu-based pigments are used by many of the manufacturers and that regular use of these products might result in exposures up to 5-10 times the maximum USP/ICH limits for inhalation drugs. The overall conclusion of the publication suggests that cannabis users may be inhaling unsafe levels of toxic metals as rolling papers burn, particularly those that contain dyes or have metallic-colored tips. These metals are not typically required by most states, which is further justification to expand the regulated panel beyond the big four heavy metals (Pb, Cd, As, Hg) to ensure consumer safety.

It is estimated that vaping accounts for almost 50% of all cannabis consumption today. So, any information in the public domain about vaping and the potential for contaminants in the vape extract is of critical importance. Unfortunately, we know that many of the components used in today’s vaping devices including tanks, cylinders, posts, threads, mouthpieces, coils, atomizers, battery terminals, etc., are prone to corrosion under the right pH and thermal conditions, potentially resulting in metal particulates ending up in the vape liquid (12). For example, some of the most common materials being used in the manufacturing of these components include glass (Si, Na, Al, B), plastic (Ca, Zn, Si, Mg), stainless steel (Fe, Cr, Ni, Co, Mn), nichrome (Ni, Cr), kanthal (Fe, Cr, Al), brass (Cu, Zn, Pb) ceramic (Si, Al, Ca, B, Zr), and solder (Sn, Pb). Additionally, most vaping devices have variable voltages, allowing the user to select different vaping temperatures, based on the desired therapeutic or psychoactive effect. This means that if a higher temperature is selected, the amount and number of corroded metal particles being aerosolized could be significantly higher.

There have been very few studies carried out to understand if any of those metal particles end up in the aerosol at elevated vaping temperatures, because it is such a challenging analysis which requires a high level of operator expertise to trap and collect the aerosol containing mixtures of cannabinoids, terpenes, diluent oils, and other hydrophobic liquids in the vape tank and introduce them into the ICP-MS for analysis. It might be assumed that the high temperature vaping process of up to 600 °C would be the logical reason for corrosion of the metallic components. However, that may not necessarily be the case. A recent study by researchers at the National Research Council of Canada took 20 legal and 20 illicit unused THC vape cartridges and characterized them for a panel of 10 elemental contaminants including Cu, Zn, Pb, Fe, Cr, Ni, Mn, As, Cd, Hg (13). The legal ones were purchased at a local vape store, while the illicit ones were obtained from local law enforcement agencies. It’s also important to mention that none of the cartridges were older than eight months. However, what the researchers uncovered was quite revealing. Using ICP-MS they found high levels of all 10 toxic metals in the vape carts, which is not surprising.However, what they also discovered was variable sized particles dispersed throughout the liquid in a heterogenous manner. Moreover, on further investigation using SEM coupled with energy dispersive XRF (EDS), they confirmed these in fact were metal particles suspended in the THC liquid. It appeared the corrosion had likely taken place while the vape carts were on retailers’ shelves with the older devices showing higher levels of metal contaminants. To exemplify this, 

 is a bar graph summary of the results for all 20 of the legal and 20 of the illegal vape samples.

It can be seen that even though the big four heavy metals were generally below the regulated limits in many of the samples with the exception for lead, the other unregulated metals were in the hundreds of ppm, which again would escape the scrutiny of most state regulators. It’s also worth noting that lead in many of the samples was as high as 50 ppm in the illegal vapes, which suggests that it was either corrosion of the brass coil/wire or the lead-based solder of the battery terminals. On further investigation, using laser ablation ICP-MS, they found extremely high levels of Si, Na and Al in some of the particles, which perhaps infers that there could have been delamination of the glass tanks, resulting in minute particles of glass shards floating around in the vaping liquid. So, it asks the question, what type of glass components and metal alloys are used in the manufacturing of vape carts and pods and are they of the highest purity for this type of application? And in particular, are they up to strict quality standards for manufacturing drug products? Let’s take a closer look at how these types of materials are tested in the pharmaceutical industry.

The suitability of glass for storage of corrosive chemicals used in the pharmaceutical industry was recently highlighted by Daniel Haines, PhD, Head of Pharma Services, North America,Schott AG and co-workers in the 

Journal of Pharmaceutical Science and Technology 

(14). Glass is by far the most common material used for pharmaceutical containers because of its chemical inertness and the excellent container closure properties. Nevertheless, the interaction with the drug product and various chemicals used in the manufacturing process can alter the interior glass surface and generate adverse effects. In this study, the chemical durability of borosilicate glass (Type 1 tubular and Type 1 molded glass), and molded soda lime glass (Type 2) vials were assessed using different corrosive solutions including citrates, phosphates, and chlorides defined in USP Chapter <1660>, Evaluation of the Inner Surface Durability of Glass Containers (15).

The suitability of the three different kinds of glass vails were evaluated for chemical attack based on differences in the interior glass surface using scanning SEM, the number and concentration of elements leached into solution, changes in the solution pH and visual inspection of suspended particles. The observed chemical durability differences are directly related to a combination of the glass composition, manufacturing, and processing conditions. While all three types behaved similarly when filled with ultrapure H

O, significant differences were observed when the vials were filled with a more aggressive solutions such as 15% potassium chloride (KCl).

The study is recommended reading, but in summarizing the findings, it was found that with the more aggressive solutions, the tubular borosilicate glass containers were more durable than the molded glass variety, while the soda glass was the least durable of the three types, with significantly more reactive sites and discoloration. 

shows one dataset from the study—concentrations of the major elements in the three different types of glass by inductively coupled plasma - optical emission spectrometry (ICP-OES) over an extended period of time at elevated temperatures, emphasizing that the tubular borosilicate glass is slightly more corrosion-resistant than the molded variety, with the molded soda glass faring the worst. This is reasonable to expect based on the reduced chemical durability of soda lime compositions and their known susceptibility for dissolution and surface cracking in the presence of corrosive solutions.

The overall conclusion of the study was that these factors should be given prime considerations when selecting containers and vials for drugs with active ingredients and also for excipients and water-based diluents with high levels of salt components. For that reason, soda glass would not be a good choice for parenteral applications for intravenous drug delivery.

This study could potentially have serious implications for the cannabis industry where glass is one of the most widely used materials for storage of cannabis extracts, oils, and diluent oils, and often for the equipment used in the cannabinoid extraction and purification process. So, it’s a very pertinent question to ask whether the optimum grades of glass are being used for the different applications including distillation vessels, storage containers, dropper bottles, consumer delivery devices such as, bongs, vape carts, etc., particularly if the application uses elevated temperatures. The limited evidence in the public domain, of ensuring the purity of glass used in vape carts, suggests that this is probably not the case (16). It’s worth noting that the pharmaceutical industry also has strict quality control procedures for plastic materials, which although different from assessing glass, is equally as stringent to ensure there is minimal contamination of drug raw materials, ingredients, and products (17).

Stainless steel is widely used in many areas of the cannabis industry, including cutting, and grinding equipment, extraction/processing vessels, mixing tanks, storage containers, screens, vaping delivery devices and much more. It is probably the most widely used material in the preparation, processing, and manufacturing of cannabis consumer products. However, because cannabis and hemp are hyper-accumulating plants, which naturally absorb metals from the soil, even surfaces, and materials they are in contact with, there needs to be careful consideration to the purity and quality of the grades of stainless steel used.

This has been exemplified by recent reports of high chromium levels in cannabis flower and biomass samples, which have been attributed to a combination of cutting with stainless steel shears and/or grinding with stainless steel blades (18). Normally this might escape the scrutiny of most state regulators, because the majority of states only require the big four heavy metals (Pb, Cd, As, Hg) to meet compliance. However, states that include Cr and/or Ni in their panel of regulated heavy metals would immediately flag this as being a potential problem, especially if the cannabis material was intended for vaping applications, where the inhalation action limits are significantly lower than for orally delivered products.

It is therefore worth understanding what types of stainless-steel are used in the cannabis industry, because it is such a common material found in many areas of the production process. As there are a multitude of types and grades of stainless steels available, with different physical and chemical properties, it is critically important that the optimum quality is used to ensure they do not contaminate any of the products they are in contact with.

We should therefore learn from the pharmaceutical industry, where using the wrong grade of stainless steel can result in premature oxidation of the surface producing corrosion and potential failure of the equipment. This could have a catastrophic impact on the cannabis manufacturing process not only for the stainless-steel cutting or grinding equipment used to prepare the cannabis plant material for cannabinoid extraction, but also from vessels used for extraction, purification, storage, and delivery purposes (19).

In the life cycle of the cannabis and hemp industry, it is not obvious where the heavy metal regulatory landscape will eventually end up. Clearly the big four toxic metals as required by the vast majority of US jurisdictions are not enough, but what is a realistic panel that reflects the real world of cannabinoid production? New York with eight elements and Michigan with seven, including inorganic arsenic are leading the charge with a few other states like Maryland and Missouri adding chromium to the big four. But it’s clear from the recent study carried out by the FDA’s Botanical Review Team (20), that they view the efforts of the states to regulate heavy metals as being inadequate. However, recent activity from the USP has sent signals to the industry that if they want to produce CBD as an Active Pharmaceutical Ingredient (API) for use as a federally approved drug formulation, they are most likely going to have to monitor additional elemental contaminants to meet the quality attributes. And it’s encouraging that standards organizations are developing standardized methods to meet these demands with National Institute of Standards and Technology (NIST) developing a 13-toxic element hemp reference material (10 assigned, three informational) and ASTM publishing an ICP-MS standard method for up to 23 different elemental contaminants in a wide variety of cannabis and hemp related matrices.

In conclusion, I believe that the current state-based regulatory system is unsustainable in the long term, as there is very little incentive to expand the list of analytes for fear of increasing the cost of testing and impacting revenue. It’s clear from the growing evidence in the public domain that it should be only a matter of time before the cannabis industry moves beyond the big four heavy metals and has an expanded regulated panel that is more in line with the pharmaceutical industry, and better reflects the real world of cultivation and production and most importantly, consumers’ safety concerns. However, an added twist along the way could be the significant amounts of synthetic cannabinoids such as delta-8 THC and THC-O-acetate (THC-O) that are being synthesized by “garage chemists” from the glut and over production of CBD products (20). The manufacturing process involves using organic solvents, concentrated mineral acids, and catalysts, such as, platinum group metals and zeolites (minerals containing aluminum and silicates) at high temperatures. The result is illegal and unregulated synthetic cannabinoids flooding the marketplace, which contain extremely high levels of toxic metals (21). As responsible members of this rapidly growing cannabis community, we all have a part to play in trying to better understand sources of contamination in the production of cannabinoids before consumer safety is severely compromised.

Nelson, J.; Jones, C.; Heckle, S.; Anderson, L. Determination of Heavy Metals In A Variety of Cannabis and Cannabis-Derived Products, First Action, 

ASTM D8469-22: Standard Test Method for Analysis of Multiple Elements in Cannabis Matrices by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), 

Barber, C.A. ; Bryan-Sallee, C.E. ; Burdette, C.Q.;Kotoski, S P.; Phillips, M.M.; Wilson, W.B.; Wood, L.J., Cannabis Laboratory Quality Assurance Program: Exercise 2 - Toxic Elements, 

https://nvlpubs.nist.gov/nistpubs/ir/2022/NIST.IR.8452.pdf

ASTM-E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, 

https://www.document-center.com/standards/show/ASTM-E691

Symposium on Measurement of Contaminants in Cannabis and Hemp Consumer Products, ASTM D37 Committee on Cannabis Standards, Symposium Chairs: Robert Thomas and Cary Black, 

http://www.scientificsolutions1.com/d37%20contaminants%20symposium%20program-1.pdf

Macaluso, F.; Goldman, S.; James, K.A.; and Van Dyke, M., Preliminary Levels and Distribution of Health-Relevant Heavy Metals in Commercially Grown Cannabis and Hemp, Journal of Testing and Evaluation, Cannabis Contaminants Symposium Proceedings (in production), 

https://www.astm.org/products-services/standards-and-publications/journal-of-testing-and-evaluation.html#about

Thomas, R.J., The Role of ICP-MS in Understanding the Toxicological Link Between Lead Contamination in Cannabis and Hemp Products and Human Disease – Part 1 and 2, 

http://www.scientificsolutions1.com/the-role-of-icp-ms-in-understanding-the-toxicological-link-between-lead-contamination-in-cannabis-313507.pdf

Foran, A.; Slater, L.; Walton, M.; Thomas, R.; Gluodenis, T., Profiling Trace Metals of Toxicological Concern in Commercially CBD Tincture Oils, 

American Journal of Biomedical and Life Sciences

http://www.sciencepublishinggroup.com/j/ajbls

U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, Toxicological Profile for Tin, 

https://www.atsdr.cdc.gov/toxprofiles/tp55.pdf

Florida Department of Agriculture and Consumer Services Division of Food Safety

https://ccmedia.fdacs.gov/content/download/91911/file/hemp

Wright, D.; Jarvie, M. M.; Southwell, B.; Kincaid, C.; Westrick, J.; Perera, S. S.; Edwards, D.; Cody, R. B., Elemental composition of commercially available cannabis rolling papers, 

https://pubs.acs.org/doi/10.1021/acsomega.3c09580

Thomas, R.J., The Challenges of Measuring Heavy Metal Contaminants in Cannabis Vaping Aerosols, Analytical Cannabis, 

http://www.scientificsolutions1.com/the-challenges-of-measuring-heavy-metal-contaminants-in-cannabis-vaping-aerosols-313041.pdf

Gajdosechova, Z.; Marleau-Gillette, J.; Turnbull, M.J.; Petts, D.C.; Jackson, S.E.; Cabecinha, A.; Abramovici, H.; Waye, A.; and Melanson, J.E., Evidence That Metal Particles in Cannabis Vape Liquids Limit Measurement Reproducibility, 

Haines, D.; Gober-Mangan, E.; Klause, M.; and Rothhaar, U., Comparative Predictive Glass Delamination Study Tubular Borosilicate vs Moulded Borosilicate and Soda Lime 20 ml Vials, 

https://www.researchgate.net/publication/363315970_Comparative_Predictive_Glass_Delamination_Study_Tubular_Borosilicate_vs_Moulded_Borosilicate_and_Soda_Lime_20_ml_Vials

USP Chapter <1660>, Evaluation of the Inner Surface Durability of Glass Containers, 

https://www.uspnf.com/sites/default/files/usp_pdf/EN/USPNF/revisions/c1660.pdf

Thomas, R., What the Cannabis Industry Should Know About Glass, 

http://www.scientificsolutions1.com/what%20the%20cannabis%20industry%20should%20know%20about%20glass.pdf

Thomas, R., What the Cannabis Industry Should Know About Plastic, 

http://www.scientificsolutions1.com/what%20the%20cannabis%20industry%20should%20know%20about%20plastic%20.pd

Donovan, D., Maryland Cannabis Regulators Warn Contamination Risk as They Expand Tests for Heavy Metals, 

https://www.baltimoresun.com/health/marijuana/bs-md-cannabis-heavy-metals-20190605-story.html

Thomas, R., What the Cannabis Industry Should Know About Stainless Steel, 

http://www.scientificsolutions1.com/what%20the%20cannabis%20industry%20should%20know%20about%20stainless%20steel.pdf

Pruyn, S.A.; Wang, Q.; Wu, C.G.; and Taylor, C.L., Quality Standards in State Programs Permitting Cannabis for Medical Uses, 

Thomas, R., PittCon 2023’s Vaping Symposium Confirms the Cannabis Industry Still Has Safety Concerns About Vaping Devices, 

http://www.scientificsolutions1.com/pittcon%202023%E2%80%99s%20vaping%20symposium%20confirms%20the%20cannabis%20industry%20still%20has%20safety%20concerns%20about%20vaping%20devices.pdf

The Unregulated Distribution And Sale Of Consumer Products Marketed As Delta-8 THC, 

https://irp.cdn-website.com/6531d7ca/files/uploaded/USCC%20Delta-8%20Kit.pdf

 is the principal scientist at Scientific Solutions, a consulting company that serves the educational needs of the trace ele­ment user community. He has worked in the field of atomic and mass spectroscopy for almost 50 years, including 24 years for a manufacturer of atomic spectroscopic instrumentation. Rob has written over 100 technical publications, including a 15-part tutorial series entitled, 

. He is also the editor and frequent contributor of the "Atomic Perspectives" column in 

 magazine, as well as serving on the editorial advisory board of 

. In addition, Rob has authored six textbooks on the fundamental principles and applications of ICP-MS. His most recent book is entitled 

A Practical Guide to ICP-MS and Other AS Techniques

, which was published in September 2023. Rob has an advanced degree in analytical chemistry from the University of Wales, UK, and is also a Fellow of the Royal Society of Chemistry (FRSC) and a Chartered Chemist (CChem).

Thomas, R. Understanding Sources of Heavy Metals in Cannabis and Hemp Consumer Products, Part II: Is the Fractured Nature of State-based Regulations Ignoring the Evidence? 

Articles

The second part of this column will take a look at specific examples in the public domain of elemental contamination of cannabis consumer products, which shows that other elements are worthy of consideration and should be a part of the regulatory framework.

Understanding Sources  of Heavy Metals in Cannabis and Hemp Consumer Products, Part II: Is the Fractured Nature of State-based Regulations Ignoring the Evidence?

Florida is currently undergoing their own version of cannabis reform like other states across the country have gone through. On this year’s election ballot, voters will find several amendments such as one called “Amendment 3” (1). Currently in the Sunshine State, medical cannabis is legal. With Amendment 3, voters will be able to decide “yes” or “no” to legalizing recreational cannabis. Along with cannabis legalization, adults that are 21 years old or older will be able “…to possess, purchase and use marijuana for personal, nonmedical reasons,” (1). Individuals will also be able to carry around 85 g of cannabis or 5 g of cannabis concentrate.

The approval of Amendment 3 would give way for medical cannabis dispensaries to sell cannabis products to consumers that are planning to consume recreationally. An additional change that could come from this amendment is that businesses that are state-licensed would receive the authorization to distribute, cultivate, and process cannabis products (1).

If Amendment 3 does not pass, Florida’s constitution will not be changed, and medical cannabis will continue to be the only form of cannabis legal in the state.

To secure its passage, Amendment 3 will need to gather around 60% of votes (1). If Florida passes this amendment, it will be added to the growing list of states that have approved cannabis recreationally.

The issue of recreational cannabis in Florida has been an indicator of presidential candidate Donald Trump’s standpoint on cannabis policy. In a September 8 post on the Truth Social platform, Trump stated (2), “As I have previously stated, I believe it is time to end needless arrests and incarcerations of adults for small amounts of marijuana for personal use. We must also implement smart regulations, while providing access for adults, to safe, tested product. As a Floridian, I will be voting YES on Amendment 3 this November. As President, we will continue to focus on research to unlock the medical uses of marijuana to a Schedule 3 drug, and work with Congress to pass common sense laws, including safe banking for state authorized companies, and supporting states rights to pass marijuana laws, like in Florida, that work so well for their citizens.”

In the past, Trump has stated his support for leaving recreational cannabis legalization up to individual states and for rescheduling it under the Controlled Substances Act (3). In mid-October, 

Vice President Kamala Harris unveiled her cannabis legalization plan

 as part of her 2024 presidential campaign.

, Chief Scientific Officer at Modern Canna Labs, discussed the potential impact of Florida's cannabis legalization on the industry, both medical and recreational, and regulations. “I think that we're going to keep both [medical and recreational cannabis] in Florida,” Glaros explained. “From my understanding, is there will be a recreational and there will be a medicinal market. How testing may look different, how pricing may look different, it's hard to say until it passes… because we are a vertical system already, I don't foresee many changes as far as testing regulations go, and that's ultimately probably to preserve the safety of the consumer, because when you think about it, being a patient in the medicinal program costs money. So if you don't have to pay that additional money to be in the medicinal program and you decide to go the recreational route, you still want to protect those patients who may be using it through the recreational market. So I would foresee testing regulations staying similar. When you look at the hemp regulations in Florida, the hemp regulations actually all refer to the cannabis testing regulations and say that products in Florida should be tested the same way that cannabis products are. So that's how the Florida Department of Agricultural and Consumer Services has gone about handling hemp. I would foresee recreational cannabis handled in a similar way.”

The issue of cannabis for recreational purposes is also on the November ballot in 

Maldonado, M.; Rodriguez, E. What to know about amendment 3, Florida’s marijuana amendment on the 2024 election ballot 

https://www.cbsnews.com/miami/news/florida-marijuana-amendment-3-2024-election-ballot/

Concepcion, S.; Tsirkin, J.; Thorp V, F.; Richards, Z. Trump says he will vote yes on Florida ballot measure to legalize marijuana 

https://www.nbcnews.com/politics/donald-trump/trump-says-will-vote-yes-florida-ballot-measure-legalize-marijuana-rcna170197

Allen, J.; Bowman, B.; Kamisar, B.; Kapur, S.; Korecki, N.; Nicholas, P.; Pettypiece, S.; Reilly, R.; Seitz-Wald, A.; Smith, A.; Tsirkin, J.; Wong, S.; Wollner, A.; Bland, S.; Terkel, A.; Carman, J. Harris and Trump: Compare where they stand on key issues 

https://www.nbcnews.com/politics/2024-election/harris-trump-stance-issues-policies-president-race-rcna150570#marijuana

On November 5, 2024, Floridians will decide on Amendment 3, which proposes legalizing recreational cannabis. Former President Trump has stated support for this measure, aligning with his stance on state-level cannabis policies.

Florida to Vote November 5 on Legalizing Recreational Cannabis

David Hodes has written for many cannabis publications, and organized or moderated sessions at national and international cannabis trade shows. He was voted the 2018 Journalist of the Year by Americans for Safe Access, the world’s largest medical cannabis advocacy organization.

Growers explore the possibilities of a more manageable operation as research about the chemistry of the soil takes center stage.

Growing cannabis has been an ongoing experiment across the world for thousands of years, but sharply increasing with the legalization of recreational cannabis in certain jurisdictions around 2014. More discoveries about microorganisms in soil (or using no soil at all) and other post-harvest options are emerging all in an effort to grow faster and more economically with a better quality outcome.

Growing cannabis today is about accessing and applying more mainstream agricultural techniques and processes in the soil composition, in the grow methodologies, and in the post-harvest development.

An accelerated cultivation evolution is happening, with the exploration of such old-but-new-to-cannabis growing technologies as aeroponics challenging hydroponics, even as research into the composition of soil has become focused on the value of bacterial fungi systems for both soil and non-soil-based grows.

This installment of the “Tech Innovations” column will discuss how growers can manage nutrient development of the plant’s soil highway; why using no soil or water at all may provide the best way to control growth, and eventually precisely replicate, a specific cultivar; as well as better ways to dry or cure the plant.

The cannabis plant, as most common plants, uses a system of nutrient uptake for its specific needs, including mechanisms to effectively “mine” the soil for nutrients (1).

The author of many books on growing, such as 

Teaming With Microbes: The Organic Gardener’s Guide To The Soil Food Web

 (2), lawyer and garden writer, Jeff Lowenfels (3) describes the basic function of a plant’s nutrition uptake. “The basic system for the plant, whatever kind of plant it is, puts out an exudate (carbon-rich materials often sticky to human touch that helps stabilize soil and interactions with other organisms around the roots [4]), takes photosynthetic energy and makes these chemicals that it drops out through the root system,” said Lowenfels. He further explained how, “It attracts bacteria and fungi. The bacteria and fungi eat the carbon that are in these exudates, and they attract nematodes and protozoa who eat the bacteria and the fungi. So, you get a lot of eating going on, and then you got a lot of pooping going on.”

What's “pooped” out, he said, are plant usable nutrients, or nutrients in a form the plant can take up. “The microbes put an electrical charge on these nutrients, and that's how they get into the plant,” Lowenfels mentioned. “The exudates can be changed for the plant to get what it needs.”

For example, in cannabis, the plant requires a certain kind of bacterial fungal system, and the exudates are adjusted by the cannabis plant itself to be able to meet the needs of the plant for the nutrients that the plant's going to take in.

Lowenfels said that there are two other things going on. “Some of these exudates attract mycorrhizal fungi, which are different kinds of fungi. They actually go into the root and take the exudate, and in return for the exudate they give the plant water, phosphorus, nitrogen, zinc—basically all sorts of good stuff. If the fungi doesn't give the cannabis plant the good stuff, it doesn't get the nutrients from the cannabis plant. So, it's a symbiotic relationship.”

There are three different loops in the system where the cannabis plant gets its nutrients: the aforementioned poop loop, which is the basis of the soil food web discovered by soil biology pioneer Elaine Ingham where things are eating and then pooping in plant-usable form (5); the fungal loop, where mycorrhizal fungi had an impact; and the bacteria loop.

According to Lowenfels, that last loop “is very new stuff,” that has “only been known about since 2017, and only really known about what is really going on since 2020.”

Under that system, some of the bacteria that are attracted by the exudates aren't eaten and pooped out, but rather move directly into the root. To protect themselves from the activity that occurs in the cell when they move in, they end up improving the plant’s nitrogen uptake. “By fixing that nitrogen, they're able to spray the inside of the cell and protect themselves,” Lowenfels said. “So, they fix nitrogen inside the root (6), which is a third way of getting nutrients to the plant, and those are endophytic bacteria, or plant beneficial bacteria (7), that feed the plant.”

The key thing about growing cannabis is that a lot of the bacteria and some of the fungi are carried in the seed, noted Lowenfels. If a grower takes the seed and mistreats it, such as sterilizing it, that impacts some of the bacteria that would have jumped out of that seed once it germinated. “So, you reduce the kinds of bacteria that the cannabis plant wants,” he explained.

Sterilizing the seed ends up screwing up the development of the plant. But there are other methods that affect the plant nutrition process. “Growers do things like taking a cannabis seed and putting it in a wet paper towel to get it to germinate,” Lowenfels illustrated. “Once it germinates, they put it in the soil. The problem is that a lot of the bacteria have jumped off that seed during germination. It stays in the towel. So, you’ve got to bury part of the towel as well.”

The soil-food web system is all about the workings of bacteria and fungi. The bacteria adhere particles of soil to one another and begin soil structure formation. “When you grow cannabis, people tell you to throw the soil away. They say that you got to start with new soil all the time,” said Lowenfels.“This is all BS, because if you follow the soil food web system, and you do what you're supposed to do, such as teaming with the microbes, you populate your soil with the right microbes and help build the soil structure. If you reuse the soil, you end up with soil that's got a lot of the exudates in it that the plant needs. Why are you throwing it away?”

What he recommends is making a new hole in the previously used soil, putting the new plant in and letting it grow right in the root system of the old plant. “The soil has all the exudates; it's got all the bacteria. It's got all sorts of amoebas and all the protozoa you'd ever want to have, and it's got these tunnels that are already drilled that the roots can grow into.”

A useful new tool mentioned by Lowenfels is the Microbiometer (8). This is a testing kit supported by an app, which is a new way of testing for microbial biomass and fungal bacteria ratio to determine the health of the soil. Data gathered with each testing helps a grower see if their soil management practices are working. “We're getting to the point now where we've got a complete database of all of the life in the soil,” he said. “It's just a question [of] how do you and I as lay people read what's in our soil to compare to that database. We're beginning to get people working on cell phone apps and things like that.”

More recently, there have been researchers investigating aeroponics as a viable process of growing plants without soil in an air or nutrient mist environment. Aeroponics allows plants to have 100% access to CO

 for photosynthesis, and use 70% less water than hydroponics, according to an article (9) in 

Modern Applications of Plant Biotechnology in Pharmaceutical Sciences.

Aeroponics has been used to grow lettuce, tomatoes, and cucumbers since the late 1990s. But it’s becoming a more interesting method of growing plants, including cannabis.

Kurt Livesay is the owner of Dynamite AG (10), a plant research and consultancy company, and a certified crop adviser through the American Society of Agronomy. He said that in the early days of cannabis cultivation, such as 2015 to 2019, there was talk of growing in a sterile environment, (i.e., no microbiology present in the grow), “which I think is, in retrospect, absolutely absurd,” Livesay expressed. “Now there's all kinds of studies coming out about the aeroponic rhizosphere.”

Rhizosphere has been described as the volume of soil influenced by roots but may also be extended to describe root–soil interfaces (11). They are complex and highly dynamic environments, according to an article in 

, where an immense number of interactions between roots, minerals, organic compounds, solutes, gases, and micro-organisms drive the biogeochemical cycling of elements (11).

So, there is still microbiology in aeroponics, Livesay said, and it's considerably different than a soil-based media. “The rhizosphere itself is even different than what's in the recirculating nutrient solution. So, it is by no means a sterile environment. And people are saying, oh, you know, it's disease free. Well, the hell it is. Nothing is disease free. But can it substantially reduce some of these risks? Yes, absolutely. That part is true.”

Aeroponics is more efficient than hydroponics, according to Livesay, but the jury is still out on the best system to use. He explained, “In hydroponics, there is a lot of water-to-root contact. A grower could create an anaerobic environment (which is the lack of free oxygen [12]), and can drown those plant roots. It happens all the time in commercial agriculture, where we don't have enough oxygen there. That’s a fairly common problem with hydroponics. But that is something you never have to worry about with aeroponics, because they're constantly in oxygen.”

One of the challenges of the aeroponic system is the actual size of the water droplets. “It’s about how small of a droplet are we getting to the roots themselves. Because the smaller the droplet size, theoretically, the easier the uptake,” said Livesay.

The early research on aeroponics dates back to the 1950’s, said Livesay, and it was on coffee and tomatoes. “Aeroponics has been applied predominantly for high value crops, because it is a very capital-intensive venture to start out with,” he explained. “To build a DIY aeroponic system is not that expensive. But to have the kind of control over it that commercial growers are going to seek and actually need, it gets stupid expensive.”

What kind of controls? “They're doing things like fertigation schedules (where nutrients are injected through an irrigation system [13]) through that mist. That nutrient solution that we’re spraying on there, it’s not just water,” said Livesay.

 (14) emphasizes the significance of fertigation schedules: “Our findings emphasize the need for precise nutrient management strategies in cannabis cultivation. Adjusting nutrient regimens in different fertigation systems yielded significant outcomes,” the study concluded.

According to Livesay, a grower has to figure out if they are going to leave this system running all the time. Are they going to spray it for five seconds every hour? Are we going to spray it for an hour every 24 hours? “Figuring that out is key,” he noted.

The water solubility, and the nutrients that they’re putting in there, are other controls a grower needs to know. “The problem is that it's all based on electrical conductivity (EC),” Livesay lamented. Electrical conductivity, also called EC, is a measure of a material's ability to conduct an electric current often used to assess the concentration of ions or dissolved substances in a solution or to evaluate the purity or quality of water (15). “EC has got to be the stupidest freaking thing that we've come up with in agronomy in general, whether we're talking commercial or hydroponic, controlled environment, whatever. It is one of the dumbest measurements we've ever come up with, because it makes us overconfident and doesn't actually tell us anything.”

Livesay further added, “I don't think that you need to be, necessarily, a botanist or a horticulturalist to be able to use aeroponics. But I do think to be able to dial it in a way to really maximize the potential of it requires a lot of math.”

Once the plant has grown, there are different techniques for curing it. One of those methods is burping, which is the process of releasing the CO

 and moisture and introducing fresh air as the plant cures. “Burping sucks,” said Ed Rosenthal who is a leading cannabis horticulture authority, author, educator, social activist, and legalization pioneer who was one of the co-founders of 

. “There is no right kind of burping, because when you're keeping moist marijuana in an enclosure, you're inviting bacteria, and that actually destroys many of the terpenes.”

He discussed using TerpLock (16), a curing product from Grove Bags. TerpLock pushes out excess moisture and oxygen without damaging terpenes, according to its website, allowing both the cannabinoids and terpenes to mature. A grower puts dried flower into the bag, leaving about 25% empty as headspace, seals it, and lets it sit for two weeks to as much as two months for optimal potency.

Curing cannabis is not as easy as people think. “People talk about curing cannabis, but I think that there have to be more studies on that,” said Rosenthal. “There are several things that are happening as cannabis ages in one way or another. One is that some of the terpenes, especially the small molecular terpenes, evaporate pretty quickly, especially if the temperature is above 70°F.”

There is also oxygenation going on. “The terpenes actually change in the presence of oxygen,” he stated. “They change from one kind of terpene to another. I think that happens a lot, and that really hasn't been studied. If you're in a room where there's curing going on and there's a deep, deep smell of terpenes in the room, those are the terpenes that are no longer on the plant.”

The idea is to keep those terpenes on the plant, and that can be done by lowering the temperature. “The ideal ‘drying’ would be something like 68°F with a 30% humidity.”

No matter what you are growing when, and how you want to refine the process, there is a broader industry need to re-engineer how it works. “I'm not talking about today or next year necessarily, but I think that ultimately, it's a lot easier to brew beer than it is to grow cannabis,” said Rosenthal. “Growing cannabis requires all this expensive equipment that just isn't required in making beer. So, I think that at some point, most tetrahydrocannabinol (THC) is actually going to be produced in yeast that has had THC added to the genetic profile. You will be able to grow a whole crop of THC in four or five days without lights, without planting, without anything.”

Here’s how it could work: A grower would buy an inoculant with yeast that produces THC and some yeast that produces cannabidiol (CBD). Different yeast gives the grower some different terpenes. You then boil a pail of sugar water, drop in yeast, which is basically what you use to brew beer, and five days later, you refine the THC from the water using a home distillation unit.

Soil chemistry, growing options, curing—all concepts that are developing and on the move in research circles to get a better cannabis product that requires less guesswork, and results in more planned outcomes. “The longer you have a mono crop, the greater the likelihood of you bringing disease pressure into that,” Livesay said. “So, biodiversity is important. When we're doing aeroponics, we do have a greater degree of control over that.”

Growers know that this amazing plant that can heal itself and communicate with other plants. “When you walk up to a cannabis plant and you touch the cannabis plant, that entire plant knows you're there, because every cell talks to every other cell,” explained Lowenfels. “There's no question that when certain bugs hit a cannabis plant, the cannabis plant in the next tent over gets a signal: ‘You better prepare yourself for that bug coming.’ Chemical signals and pheromones need to get shifted around.”

Simpler grow processes could make cannabis a more accepted agricultural product for the masses. “I think that as (cannabis) becomes more and more accepted by society, we're going to see more and more people planting it in the same way that they would tomatoes or any other vegetable that they had in their garden,” Rosenthal said. “It will be part of their gardening program.”

Connolly, E.L.; Morgan, J. B. Plant-Soil Interactions: Nutrient Uptake. 

https://www.nature.com/scitable/knowledge/library/plant-soil-interactions-nutrient-uptake-105289112/

Lewis, W; Lowenfels, J. Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web - Revised Edition. 

https://www.hachettebookgroup.com/titles/jeff-lowenfels/teaming-with-microbes/9781604692549/?lens=timber-press

https://www.jefflowenfels.com/books-by-jeff-lownfels/

Lambert, J.; Santiago-Blay, J. Plant Exudates and Amber: Their Origin and Uses. 

https://arboretum.harvard.edu/stories/plant-exudates-and-amber-their-origin-and-uses/

Wagner, S. C. Biological Nitrogen Fixation. 

https://www.nature.com/scitable/knowledge/library/biological-nitrogen-fixation-23570419/

Afzal, I; Shahzad, S.; Shinwari, Z.; Sikandar, S. Plant beneficial endophytic bacteria: Mechanisms, diversity, host range and genetic determinants. 

https://doi.org/10.1016/j.micres.2019.02.001

Buckseth, T.; Muthuraj, R.; Pandy, K.K.; Sharma, A.K.; Singh, B.P. Methods of Pre-Basic Seed Potato Production with Special Reference to Aeroponics—A Review. 

https://doi.org/10.1016/j.scienta.2016.03.041

Oburger, E.; Schmidt, H. New Methods to Unravel Rhizosphere Processes, 

https://doi.org/10.1016/j.tplants.2015.12.005

https://doi.org/10.1007/978-94-017-8801-4_158

Malik, M.; Senkyrik, J.; Tlustos, P.; Velechovsky, J. Effect of Augmented Nutrient Composition and Fertigation System on Biomass Yield and Cannabinoid Content of Medicinal Cannabis (Cannabis sativa L.) Cultivation. 

https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1322824/full

https://grovebags.com/curing-with-terploc/ 

 has written for many cannabis publications, and organized or moderated sessions at national and international cannabis trade shows. He was voted the 2018 Journalist of the Year by Americans for Safe Access, the world’s largest medical cannabis advocacy organization.

Hodes, D., More and Better Grow Options Emerging, 

A look at how growers explore the possibilities of a more manageable operation as research about soil chemistry takes center stage.

More and Better Grow Options Emerging

Cannabis product suppliers (cultivators and brands) are required to have their products lab tested before products may be sold to customers. In most states, the process essentially works as follows (see 

Regulators license independent labs to conduct product testing.

Testing Labs send samplers out to suppliers’ sites, where they select product samples from batches presented to them by suppliers. Batches are tagged (that is, identified) with labels from a product tracking system, such as Marijuana Enforcement Tracking Reporting Compliance (METRC).

Labs perform product testing on the selected samples, record those results in METRC, and send copies of the lab reports back to the suppliers. Suppliers then remit payment to the labs for performing the lab tests.

Suppliers sell their lab-tested products to customers through dispensaries, providing test results (on demand).

As an aside, suppliers cover their costs of having their products lab tested by passing those costs on to consumers in the form of higher prices. So, it’s a bit of a misnomer to say the supplier pays for the testing, because no matter who conducts the testing, the costs of doing so are ultimately borne by consumers. When I say “suppliers pay for testing,” what I actually mean is “suppliers remit payment to labs.”

For quite some time, the problem of “lab shopping” — suppliers finding labs willing to generate inaccurate results, either higher-than-actual levels of tetrahydrocannabinol (THC) or lower-than-actual levels of pesticides, mold, or other toxins — has been identified and discussed in the industry. The problem of lab shopping could potentially be resolved by (somehow) determining which labs were producing inaccurate results and sanctioning or shutting down those labs. In this case, the basic testing framework, that is, the process described above, could potentially be retained.

However, an additional, more insidious, new problem has been identified, as Trent Hancock, legacy business owner and cultivator, explains it: suppliers are sending clean and/or high THC samples to labs for testing, while selling other inferior products under those lab tests (for example, they’re switching out products) (see 

, [1] and [2]). This new problem is worse, because it doesn’t require corrupt labs to participate in the fraud, like the lab shopping problem does. Rather, it can be accomplished using unwitting labs who are generating accurate testing results on decoy or stand-in products.

Unfortunately, trying to address the problem of intentional misrepresentation of the quality of cannabis products by suppliers won’t be solved by using methods that still keep the suppliers in the loop of the lab testing process. That is, the problem won’t be solved using such methods as:

Mandating suppliers test their products using several independent labs

Assigning suppliers to labs or randomizing labs

With any of these methods, suppliers will still be able to switch out products. The only way to resolve both problems of lab shopping and product switching is to reconfigure the testing process — or at least parts of the process — to take suppliers out of the loop. That is, products must be tested after they leave the control of the suppliers and before they are sold to consumers (see Figure 2, [3]).

This leaves product testing to be conducted either by distributors and/or by dispensaries.

There are two separate sets of information provided by labs when they test cannabis products. The first set of information is the profile of cannabinoids and terpenes contained in the products. Consumers use this information to help them understand the type of health and/or mood effects that products might be expected to generate. The second set of information provided by lab testing is the amount, if any, of contaminants contained in the products. Consumers use this this information to establish that the products aren’t toxic. Products must be labeled with cannabinoid (and in some states) terpene profiles. Tested products are assumed to be non-toxic; labeling products as such is not required.

Given all this, we are left with two potential alternatives:

The current framework for the lab testing of cannabis products enables product suppliers to use more favorable testing results to misrepresent less favorable products. This article presents an alternative framework that increases the costs, and thereby decreases the incentives to engage in such misrepresentations.

Featured Content

Check Out the Cannabis Science and Technology September/October Issue!

Check Out Our Higher Education Supplement!

How cGMP Compliance Can Tackle Inconsistent Testing

Ep 23, Part III: Accreditation in the Cannabis Industry with Susan Audino

Call For Papers: Cannabis Science and Technology 2024/2025 Issues