The Cannabis Laboratory
That said, probably the most common type of cannabis lab in legalized states and Canada is analytical/QA, to provide certified product analysis for labeling and to meet state/national standards and regulations. As the industry matures from its early "wild west" phase into more of an established and organized community, the vision of what a cannabis testing lab looks like has similarly been brought more sharply into focus. Standard tests look for various THC (∆9-Tetrahydrocannabinol) and cannabinoid-related results, pesticides, heavy metals, residual solvents, and microbial contaminants like E. coli, Salmonella, and various yeasts and molds. More recently, water activity has become a standard test in many canna labs as well. As the state of California has recently (January 2019) adopted their regulations into law, those tests and related thresholds and limits are arguably the best current template a lab might use to determine the requirements that are likely to apply to them in any other state as things progress.
Regulations and standards
Standards apply to cannabis labs as they do to any labs, and baseline certifications and standards include GLP/GALP and ISO 17025/9001:2015. Additionally, while some disconnects between federal and state laws do exist, QA/QC are still subject to 21 CFR Parts 210 and 211 Part 11, and, in New York for example, the DEA.
Along with the several areas of testing related to the seed-to-sale industry come regulations and standards, managed by several different bodies. For instance, in California, state agencies involved include:
- California Department of Food and Agriculture (regulation and licensing of marijuana cultivation)
- California Department of Public Health (monitoring and licensing of the manufacturing of marijuana edibles)
- California State Water Resource Control Boards (regulation of the environmental impacts of growing marijuana on the water supply)
- California Department of Fish and Wildlife (mitigation of cultivation-related impacts on local environments)
- California Department of Pesticide Regulation (regulation of what marijuana can be exposed to during cultivation)
Laboratories in most states will be subject to similar regulation, according to their particular role in the industry. There are various validation consultants and companies who have begun to specialize in this industry. Also, some standards organizations, resources and recommendations from existing organizations have emerged, including:
- A2LA Cannabis Testing Laboratory Accreditation Program
- APHL Guidance for State Medical Cannabis Testing Programs
- Cannabis Industry Journal
- Cannabis Safety Institute
- Colorado Department of Public Health and Environment's marijuana testing reference library
- Foundation of Cannabis Unified Standards (FOCUS)
- Leafly's State-by-State Guide to Cannabis Testing Regulations
- National Cannabis Industry Association (NCIA)
- ORELAP Accreditation for Cannabis Testing
For more about regulations and standards for cannabis laboratories, see Regulatory Compliance.
Testing and workflows
Standard cannabis QA testing includes:
- Potency (cannabinoids)
- Terpenoids (optional)
- Strain (terpenoid/cannabinoid ratios; optional)
- Residual solvents (volatile organic compounds or VOCs)
- Heavy metals
- Water activity
- Moisture content
- Foreign materials
- Mold/fungus/yeast and microbiological contaminants/pathogens
These types of testing obviously break down into individual analytes and metabolites, with over 750 constituents existing in cannabis.
Methods and their workflows depend on the type of lab (extraction only, QA/QC, commercial, production) but generally (apart from extraction-only labs) consist of easy, secure web portal-enabled test requests; chain of custody (COC) tracking of samples (with RFID or barcode); test/instrument assignment (see below for more on this); QC sample inclusion; any number of analyst, peer and/or supervisory reviews; notification of out-of-range results; and certificate of analysis (COA) reports (able to be emailed and/or retrieved by secure web portal).
Analytical aspects of cannabis
What aspects of cannabis are actually being analyzed, and how? The following, is taken from Chapter 3 of Past, Present, and Future of Cannabis Laboratory Testing and Regulation in the United States on LIMSwiki.
Cannabinoids, active chemical compounds that act in a similar way to compounds our body naturally produces, and new cannabinoids continue to be identified during cannabis research. Many of our body's cells have cannabinoid receptors capable of modulating neurotransmitter release in the brain and other areas. The plant's cannabinoids vary, with each bonding to specific receptors in our body, providing differing effects. From a theoretical and medical standpoint, crafting a strain of cannabis that has specific cannabinoids that can aid with a particular malady, while also carefully reproducing the grow conditions to consistently make that strain in the future, is a desirable but difficult goal to achieve. However, even as new strains are developed, identifying an existing strain effectively has its own set of challenges, as Mudge et al. point out: "the total [tetrahydrocannabinol] and [cannabidiol] content is not sufficient to distinguish strains [though] a combination of targeted and untargeted chemometric approaches can be used to predict cannabinoid composition and to better understand the impact of informal breeding program and selection on the phytochemical diversity of cannabis."
Lab testing of cannabinoids is done primarily as a measure of psychoactive "potency," though cannabinoids have many other potential therapeutic uses. Current laboratory testing looks at only a handful of cannabinoids; more research and development of analytical techniques that can quickly and accurately detect and separate the rest is required. Some of the major cannabinoids tested for include:
- THC (∆9-Tetrahydrocannabinol): This is the most commonly known cannabinoid found in cannabis, notable for its strong psychoactive effects and ability to aid with pain, sleep, and appetite issues. Included is its analogue ∆8-Tetrahydrocannabinol (which shows notably less strong psychoactive effects than ∆9) and its homologue THCV (Tetrahydrocannabivarin), which tends to appear in trace amounts and has a more pronounced psychoactive effect, but for a shorter duration. THCV shows promise in fighting anxiety, tremors from neurological disorders, appetite issues, and special cases of bone loss. Also notable is Δ9-THCA (Δ9-Tethrahydrocannibinolic acid), a non-psychoactive biosynthetic precursor to THC.
- CBC (Cannabichromene): This non-psychoactive cannabinoid is found in trace amounts; however, it tends to be markedly more effective at treating anxiety and stress than CBD (see next). It's also notable for its anti-inflammatory properties and potential use for bone deficiencies.
- CBD (Cannabidiol): CBD is a non-psychoactive component of cannabis, typically accounting for up to 35 to 40 percent of cannabis extracts. It acts as a counter-balance to THC, regulating its psychoactivity. It's been researched as a treatment for anxiety, sleep loss, inflammation, stress, pain, and epilepsy, among other afflictions. Included is its homologue CBDV (Cannabidivarin), which is also non-psychoactive and demonstrates promise as a treatment for epileptic seizures. Also notable is CBDA (Cannabidiolic acid), a non-psychoactive biosynthetic precursor to CBD.
- CBG (Cannabigerol): This cannabinoid is also non-psychoactive but only appears in trace amounts of cannabis. If has potential as a sleep aid, anti-bacterial, and cell growth stimulant. Also notable is CBGA (Cannabigerolic acid), a non-psychoactive biosynthetic precursor to CBG.
- CBN (Cannabinol): CBN is mildly psychoactive at best and appears only in trace amounts in Cannabis sativa and Cannabis indica. It occurs largely as a metabolite of THC and tends to have one of the strongest sedative effects among cannabinoids. It shows promise as a treatment for insomnia, glaucoma, and certain types of pain.
Mandated lab testing of terpenes—volatile organic compounds that distinctly affect cannabis aroma and taste—is done primarily as a way to ensure proper labeling of cannabis and related products, including extracts and concentrates, so buyers have confidence in what they are purchasing. However, additional lab research goes into terpenes as they also show potentially useful pharmacological properties, and they demonstrate synergies (referred to at times as the "entourage effect") with cannabinoids that largely still require further exploration. Testing for specific terpenes (discussed later) is less of a standardized practice, though it's rapidly improving. Commonly tested terpenes by third-party testing labs include:
Generally speaking, a contaminate is an unwanted substance that may show up in the final product, be it recreational marijuana or a pharmaceutical company's therapeutic tincture. The following are examples of contaminates that laboratories may test for in cannabis products.
Pesticides: Pesticides represent the Wild West of not only growing cannabis but also performing analytical testing on it. One of the core issues, again, is the fact that on the federal level marijuana is illegal. Because it's illegal, government agencies such as the Environmental Protection Agency (EPA) don't test and create standards or guidelines for what's safe when it comes to residual pesticides, let alone how to best test for them. Additionally, researchers face their fair share of difficulties obtaining product to test. The end result is we don't know much about how inhalation of pesticide-coated marijuana smoke affects long-term health, and we don't have standards for pesticide application and testing. With numerous pesticide products and little oversight on what growers apply to their plants, combined with the technical difficulty of testing for pesticides in the lab, pesticides remain one of the most difficult contaminates to test for. That said, several classes of pesticides are commonly applied during cannabis cultivation and can be tested for by labs:
- avermectins: functions as an insecticide that is useful against mites, which are a common problem for cultivators
- carbamates: functions as an insecticide, similar to organophosphates, but with decreased dermal toxicity and higher degradation
- organophosphates: functions as the base of many insecticides and herbicides, valued for its easy organic bonding
- pyrethroids: functions as the base of most household insecticides and exhibits insect repellent properties
Solvents: In 2003, Canadian Rick Simpson published a recipe of sorts for preparing cannabis extract via the use of solvents such as naphtha or petroleum ether. Claiming the resulting oil helped cure his skin cancer, others hoping for a cure tried it, and the solvent method of preparation grew in popularity. Dubious healing claims aside, the solvent extraction method remains viable, though it has evolved over the years to include less harmful solvents such as supercritical carbon dioxide, which has low toxicity, low environmental impact, and beneficial extraction properties. However, chemical solvents are still used, and if not evaporated out properly, the remaining solvents can be particularly harmful to sick patients using the extract. As for what solvents should be tested for, it gets a bit trickier, though Chapter 467 of United States Pharmacopeia and The National Formulary, the Oregon Health Authority's December 2015 technical report on contaminant testing of cannabis, and the Massachusetts Department of Public Health's response to public comments on cannabis testing provide helpful guidance. Listed solvents include benzene, butane, cumene, dimethoxyethane, hexane, and pentane, among others.
Heavy metals: 2013 research on contaminant testing on the behalf of Washington State provides insights into heavy metals and why they're looked for in cannabis testing. That research, as well as other sources, tell us:
- Heavy metals contribute to several health problems, including those of a neurological nature.
- Cannabis can "hyperaccumulate metals from contaminated soils."
- Research parallels can be found in tobacco research and how the FDA regulates heavy metal content in foods.
- The most prominently tested heavy metals include arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and nickel (Ni).
 In truth, these concerns have already borne out; most recently the University of California, Davis reported in February 2017 one of its patients had contracted an incurable fungal infection from inhaling aerosolized marijuana. They later tested 20 marijuana samples from Northern California dispensaries — using specialized techniques — and found a wide variety of potentially hazardous microorganisms.
The degree to which such contaminates commonly appear in grown and stored cannabis material and to which microbiological contaminates should be tested is not clear, however. As mentioned previously, neither the U.S. EPA or neighboring Health Canada provide any significant guidance on cannabis testing, including microbiological contaminates. Like heavy metal testing, parallels are drawn from microbial testing guidelines and standards relating to tobacco and food, where they exist. As warm, moist environments are conducive to microorganism growth, maintaining stable moisture levels during cultivation and storage is essential. Regularly measuring water activity — how moist something is — is particularly useful as a front-line preventative tool to better ensure microbial growth is limited. Regardless, testing of some kind is still required by many U.S. states, including for organisms such as:
- E. coli
Methods and guidelines
Now that we've addressed what's being tested for, we can move on to how they're being tested and what's being done to improve testing methods and procedures, including associated guidelines and recommendations. It would be beyond the scope of this guide to include every state's laws and guidelines on cannabis testing; entities such as Leafly Holdings and NORML provide such online resources. Instead, this section will focus on current and promising techniques using generalizations based on information from multiple sources. If any guidelines and recommendations are known, they'll be included.
Random, representative sampling is encouraged. When dealing with solid cannabis, BOTEC Analysis recommends a "quartering" method that divides the sample into four equal parts and takes portions from opposite sections of a square-shaped arrangement of the sample. For liquid cannabis products, remembering to stir before sample collection is advised. When deriving a sample from a cannabis-laden edible, the QuEChERS approach used by food safety labs for pesticide testing has practical use. In fact, a variety of parallels have been drawn from the food and herbal medicine industries' sampling guidelines, including from the Codex Alimentarius Commission's CAC/GL 50-2004 General Guidelines on Sampling as well as various chapters of the United States Pharmacopeia and The National Formulary. As the APHL points out, "[g]ood sampling is key to improving analytical data equivalency among organizations," and it provides a solid base for any future testing and standardization efforts.
Additional sampling insight can be found by examining other states' guidelines, e.g., Massachusetts' Protocol for Sampling and Analysis of Finished Medical Marijuana Products and Marijuana-Infused Products for Massachusetts Registered Medical Marijuana Dispensaries.
Quantifying cannabinoids for label accuracy is a major goal of testing, though calculation and testing processes may vary slightly from state to state. Despite any differences, laboratorians generally agree that when testing for cannabinoids such as THC and CBD, as well as their respective biosynthetic precursors THCA and CBDA, the methodology used must be scrutinized. The naturally occurring THCA of cannabis isn't psychoactive; it requires decarboxylation (a chemical reaction induced by drying/heating that releases carbon dioxide) to convert itself into the psychoactive cannabinoid THC. Chemical calculations show that the process of decarboxylation results in approximately 87.7 percent of the THCA's mass converting to THC, with the other 12.3 percent bubbling off as CO2 gas. The problem with this in the testing domain is gas chromatography (GC) involves heating the sample solution. If you, the lab technician, require precise numbers of both THCA and THC, then GC analysis poses the risk of under-reporting THC total values. As such, liquid chromatography-diode array detection (LC-DAD) may be required if a concise profile of all cannabinoids must be made, primarily because it provides environmental stability for them all during analysis. If GC is used, the analysis requires extra considerations such as sample derivatization.
The APHL briefly describes analysis methods of cannabinoids using both LC and GC on pages 31–32 of their May 2016 Guidance for State Medical Cannabis Testing Programs. They also point to New York Department of Health - Wadsworth Center's various guidance documents (MML-300, -301, and -303) for methodologies when testing sample types other than solids, particularly using high-performance liquid chromatography photodiode array detection (HPLC-PDA). Overall, methods used in cannabinoid testing include:
- Fourier transform infrared spectroscopy (FTIR; has limitations, such as requiring standard samples tested w/ other methods)
- Gas chromatography flame ionization detection (GC-FID; requires sample derivatization for both acid and neutral compounds; good with standards like 5α-cholestane, docosane, and tetracosane)
- Gas chromatography mass spectrometry (GC-MS; requires sample derivatization for both acid and neutral compounds; good with standards like deuterated cannabinoids)
- Gas chromatography vacuum ultraviolet spectroscopy (GC-VUV)
- High-performance liquid chromatography photodiode array detection (HPLC-PDA; stable for all forms of cannabinoids)
- High-performance liquid chromatography UV detection (HPLC-UV)
- Supercritical fluid chromatography (SFC; newer technology w/ added benefits)
- Thin-layer chromatography (TLC; older, less common technology)
- Ultra-performance chromatography (UPC; newer technology w/ added benefits)
Identifying and quantifying terpenes is one of the more difficult tasks facing laboratorians:
Terpenes present an analytical challenge because they are nonpolar and structurally similar, and many structural isomers exist. Mass spectrometry (MS) cannot distinguish terpenes that co-elute from a GC column because many have the same molecular weight and share fragment ions.
Of course, types of gas chromatography work; but like cannabinoids, terpenes can degrade with the high heat of gas chromatography. Combined with the problems mentioned above, highly specialized gas chromatography processes that include additional steps, such as full evaporation technique headspace gas chromatography flame ionization detection (FET-HS-GC-FID), can be used to produce cleaner results, particularly for volatile components. It's less clear if high-performance liquid chromatography (HPLC) is used frequently; some entities such as Eurofins Experchem Laboratories claim HPLC works best for them, while others such as Restek Corporation claim the method is problematic at best.
- Full evaporation technique headspace gas chromatography flame ionization detection (FET-HS-GC-FID; tends to be semi-quantitative)
- Gas chromatography flame ionization detection (GC-FID)
- Gas chromatography mass spectrometry (GC-MS)
- Gas chromatography vacuum ultraviolet spectroscopy (GC-VUV)
- Headspace gas chromatography mass spectrometry (HS-GC-MS)
- Headspace solid-phase microextraction (HS-SPME)
- High-performance liquid chromatography (HPLC; may have limitations due to coelution of terpenes and cannabinoids at certain ranges)
Contaminate testing Notably, high-performance liquid chromatography tandem-mass spectrometry (HPLC-MS/MS) tends to be one of the most thorough methods says Emerald Scientific's CTO Amanda Rigdon. "Ninety-five percent of the pesticides out there can be analyzed by HPLC-MS/MS, although there are some that you would need a GC-MS/MS for," she says. A popular sample extraction method for detecting multiple pesticide residues in cannabis is the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, which shows "acceptable recoveries and relative standard deviations" for almost all known pesticides, though the release of heat and increase in pH of QuEChERS may degrade particularly sensitive pesticides in the sample. However, other methods such as solvent extraction (such as with acetonitrile) with dispersive solid-phase extraction (DSPE) cleanup and energized dispersive guided extraction (EDGE) may also been used. Common testing methods that have been used, after sample preparation, include:
- Gas chromatography electron capture detection (GC-ECD)
- Gas chromatography mass spectrometry (GC-MS)
- Gas chromatography tandem-mass spectrometry (GC-MS/MS)
- Liquid chromatography mass spectrometry (LC-MS; high-performance or HPLC-MS)
- Liquid chromatography tandem-mass spectrometry (LC-MS/MS; high-performance or HPLC-MS/MS)
Solvents: Testing for solvents is largely standardized into a few options, which have parallels to existing pharmaceutical testing standards outlined in Chapter 467 of United States Pharmacopeia and The National Formulary (USP <467>):
- Headspace gas chromatography/mass spectrometry (HS-GC/MS)
- Headspace gas chromatography flame ionization detection mass spectrometry (HS-GC-FID-MS)
- Full evaporation technique headspace gas chromatography flame ionization detection (FET-HS-GC-FID)
Massachusetts and Oregon—and likely other states—have used a variety of guidance documents such as USP <467>, reports from the Commission of the European Communities' Scientific Committee on Food (now the European Food Safety Authority), and the International Conference on Harmonization's (ICH) Q3C(R5) to set their action level testing values for particular solvents.
Heavy metals: The methods used for quantifying levels of highly toxic metals in plants depend on ease-of-use, level of accuracy, and overall cost. Sample preparation typically includes the use of closed-vessel microwave digestion to get the sample into solution for analysis. Once prepared, the following methods are most common for testing cannabis and other plants for heavy metals:
- Inductively coupled plasma atomic emission spectroscopy (ICP-AES), sometimes called inductively coupled plasma optical emission spectrometry (ICP-OES) (at times coupled with an ultrasonic nebulizer)
- Inductively coupled plasma mass spectroscopy (ICP-MS)
- Inductively coupled plasma tandem-mass spectroscopy (ICP-MS/MS)
Mycotoxins and microorganisms: A standard method of testing for the existence of microorganisms is through the process of culturing a sample in a Petri dish, a common diagnostic method in microbiology. Enzyme-linked immunosorbent assay (ELISA) is also used, particularly to identify mycotoxins. However, Petri culture analysis isn't rigorous, and ELISA can be time consuming, as it's limited to one mycotoxin per test. The following are other, more precise techniques that are improving laboratorians' analyses, particularly using DNA snippets of microbiological contaminates:
- Quantitative polymerase chain reaction (qPCR)
- Whole metagenome shotgun (WMGS) sequencing
- Matrix-assisted laser desorption/ionization (MALDI)
- High-performance liquid chromatography (HPLC)
- Liquid chromatography tandem-mass spectrometry (LC-MS/MS)
- Liquid chromatography electrospray ionization tandem-mass spectrometry (LC-ESI-MS/MS)
- Liquid chromatography atmospheric pressure chemical ionization tandem-mass spectrometry (LC-APCI-MS/MS)
The extent of mycotoxin testing required remains in question by several entities. The Association of Public Health Laboratories (APHL) claims "[t]here is no readily available evidence to support the contention that cannabis harbors significant levels of mycotoxins." The Oregon Health Authority takes a more middle-ground approach, noting that testing for E. coli and Salmonella will "protect public health," though Aspergillus only deserves a warning for people with suppressed immune systems due to its prevalence in the environment. USP <561> recommendations largely limit mycotoxin testing of botanical products to those borne from root or rhizome material, "which THC-containing cannabis products presumably do not possess," emphasizes the APHL. Regardless, U.S. Pharmacopeia's Chapter 561 remains a useful document for testing guidelines and limits regarding microbials. In the less common case of dealing with powdered cannabis—a relatively new THC extract form—Chapter 2023 provides at least some testing parallels, though Dr. Tony Cundell, a microbiologist consulting for the pharmaceutical industry, suggests USP <2023> doesn't go far enough for immunocompromised patients.
Somewhat related and worth mentioning is water activity and moisture content testing. As previously mentioned, warm, moist environments are conducive to microorganism growth, and regularly measuring water activity is useful for the prevention of microbial growth. The APHL references specifications from the Dutch Office of Medical Cannabis that recommend water content be between five to ten percent in cannabis.
California's newly-adopted set of cannabis regulations includes specific report requirements, including sample image, the words "Regulatory Compliance Testing" at top right and an overall pass/fail rating for the sample. Here are the COA minimum requirements:
- The term “Regulatory Compliance Testing” in font no smaller than 14-point, which shall appear in the upper-right corner of each page of the COA. No text or images shall appear above the term “Regulatory Compliance Testing” on any page of the COA.
- Laboratory’s name, licensed premises address, and license number;
- Licensed distributor’s or licensed microbusiness authorized to engage in distribution’s name, licensed premises address, and license number;
- Licensed cultivator’s, licensed manufacturer’s, or licensed microbusiness’ name, licensed premises address, and license number;
- Batch number of the batch from which the sample was obtained. For cannabis goods that are already packaged at the time of sampling, the labeled batch number on the packaged cannabis goods shall match the batch number on the COA;
- Sample identifying information, including matrix type and unique sample identifiers;
- Sample history, including the date collected, the date received by the laboratory, and the date(s) of sample analyses and corresponding testing results;
- A picture of the sample of cannabis goods. If the sample is pre-packaged, the picture must include an unobstructed image of the packaging;
- For dried flower samples, the total weight of the batch, in grams or pounds, and the total weight, of the representative sample in grams;
- For cannabis product or pre-rolls samples, the total unit count of both the representative sample and the total batch size;
- Measured density of the cannabis goods;
- The analytical methods, analytical instrumentation used, and corresponding Limits of Detection (LOD) and Limits of Quantitation (LOQ);
- An attestation on the COA from the laboratory supervisory or management employee that all LQC samples required by section 5730 of this division were performed and met the acceptance criteria; and
- Analytes detected during the analyses of the sample that are unknown, unidentified, or injurious to human health if consumed, if any.
- (f) The laboratory shall report test results for each representative sample on the COA as follows:
- (1) Indicate an overall “pass” or “fail” for the entire batch;
- (2) When reporting qualitative results for each analyte, the laboratory shall indicate “pass” or “fail”; Bureau of Cannabis Control Order of Adoption - 116 of 138
- (3) When reporting quantitative results for each analyte, the laboratory shall use the appropriate units of measurement as required under this chapter;
- (4) When reporting results for each test method, the laboratory shall indicate “pass” or “fail”;
- (5) When reporting results for any analytes that were detected below the analytical method LOQ, indicate “<LOQ”, notwithstanding cannabinoid results;
- (6) When reporting results for any analytes that were not detected or detected below the LOD, indicate “ND”; and
- (7) Indicate “NT” for any test that the laboratory did not perform.
- (g) The laboratory supervisory or management employee shall validate the accuracy of the information contained on the COA and sign and date the COA.
Authority: Section 26013, Business and Professions Code. Reference: Sections 26100, 26104 and 26110, Business and Professions Code.
In late January 2017, Pennsylvania released its temporary regulations in support of its new medical marijuana program (28 Pa. Code Chapter 1171), which includes a section on test results and reporting (1171.31). The regulations stipulate reporting by electronic tracking system, with stipulations on using certificates of analysis which include lot/batch number and the specific compounds and contaminates tested. Regulations aside, it's largely up to the laboratory—and often by extension, the software they're using—to decide how a report is formatted. Some labs like Seattle-based Analytical 360 offer clean, color-based certificates of analysis, with high-magnification photographs, the chromatogram, potency, cannabinoid content, contaminate content, and explanation of limits, with the name of the approving analyst. Others may simply generate a computer printout with the basic data and a legend. Reports may originate from the measuring device itself (e.g., an integrator in a chromatography device), a middleware or data station attached to the instrument, or a laboratory information management system (LIMS) that accepted data from the instrument.
Though not directly related to laboratory testing, it's worth noting states also have their own reporting requirements for growers, processors, and dispensaries. Both Oregon and Washington, for example, require monthly reports related to medical marijuana transfers.
As indicated in previous sections, spectrometry and chromatography have played and will continue to play an important role in cannabis laboratory testing. This should not be surprising: "mass spectrometry is superior to other spectral techniques in such features as sensitivity, selectivity, generation possibility of molecular mass/formula, and combinability with chromatography." Analyzing complex chemical compounds that have many features and which are at times difficult to differentiate from each other proves challenging, but these technologies excel in meeting that task. Refer to the previous "Methods and guidelines" section to note the specific technology associated with each molecule and contaminate. Aside from spectrometry and chromatography equipment, the analysis of microorganisms in cannabis may turn to DNA analysis methods that require additional equipment such as a thermal cycler (qPCR) or sequencer (WMGS), or ELISA, which utilizes a photometer or spectrophotometer. Of course, preparing and storing samples requires equipment as well, such as microplates, centrifuges, comparison standards, capillaries, chemicals, columns, Petri dishes, scales, and disposable gloves. Software-based data management systems may also constitute equipment and are discussed in the next section.
When it comes to purchasing lab equipment specifically for cannabis testing, a 2015 interview with Emerald Scientific's CTO Amanda Rigdon (then with Restek Corporation) provides good advice:
- Industry-specific instrumentation isn't needed in most cases as most of the techniques and equipment used in food and herbal medicine testing have strong parallels to cannabis testing.
- That said, some sample preparation tools, standards, and consumables specifically marketed to the industry may very well make the job quicker and more reliable.
- Appropriate sample preparation techniques are just as vital as the equipment you use.
- Do your research; many instrument companies are examining methodologies usable on conventional equipment, lessening the need for more expensive devices.
- If buying used equipment, make sure the original manufacturer is still in business and producing consumables and replacement parts. Make sure your planned methods match the equipment, and make sure it's not so old that it can't be serviced by a qualified technician.
Laboratories increasingly depend on software to analyze, store, and share critical data from instruments and experiments. This has led to the development of laboratory-specific software like the laboratory information management system (LIMS), electronic laboratory notebook (ELN), and chromatography data system (CDS). These and other software systems such as "seed-to-sale" programs can also play an important role in the cannabis testing laboratory.
Laboratories of all types use LIMS software to manage the wide variety of data, testing and analysis workflows, and other enterprise activities typical of them. This generally includes—but is not limited to—sample receipt, workflow management, sample tracking and analysis, quality control, instrument data management, data storage, reporting and document management. The cannabis testing laboratory is no exception, though its activities differ slightly from, for example, a clinical pathology laboratory. As such, a few additional features outside of what's typically found in a generic LIMS are required.
- sample loading screens optimized for the industry, including differentiation between medical and recreational marijuana
- pre-loaded compliant test protocols, labels, and reports optimized and readily adjustable for a rapidly changing industry
- tools for creating new, compliant test protocols, labels, and reports
- a web API to integrate with state-required compliance reporting systems
- chain-of-custody (CoC) tracking, when necessary
- support for inventory reconciliation
As previously discussed, industry-specific test protocols largely focus on cannabinoids, terpenes, and a wide variety of contaminates, including excess water. However, as regulations continue to be in a state of flux and not particularly standardized, most LIMS developers are including the ability for users to adjust their protocols and even add new ones. And while CoC functionality is not entirely foreign to generic LIMS, it's particularly important in an industry where currently transporting even a cannabis test sample across state lines can create huge problems.
In cases where daily sample processing is infrequent and only a couple of chromatography machines are used, laboratories may weigh a decision between a LIMS and a chromatography-specific CDS, although the ability to produce an acceptable certificate of authenticity (CoA) and document the CoC are still factors, along with any state reporting requirements.
Cannabis LIMS vendors
LIMS vendors who produce cannabis testing LIMS solutions are largely yet to emerge, although some existing vendor products can be adapted to the industry. One vendor who has designed a LIMS solution specifically for cannabis testing, and has several laboratory clients in various states and Canada, is the well-established LabLynx, Inc., who are also accredited with METRC track-and-trace.
Scientists on the research side of cannabis are certainly using CDSs from Agilent, Thermo Scientific, Waters, and other to manage the data coming out of their chromatography equipment, and slowly but surely some of those CDSs are beginning to also support spectrometer data management in a similar way. Additionally, some chromatography system developers will collaborate with CDS vendors to develop software drivers—code that essentially acts as a translator between a device and a program—so chromatography devices can interact fully with the CDS.
The CDS likely has a place in the cannabis testing lab as well, though it may depend on the lab's data management needs and goals. In more complex labs with multiple instruments and significant daily processing workflows, a LIMS may make more practical sense.
Some vendors like Thermo Fisher Scientific—discussed in the next chapter—offer a CDS in conjunction with its other chromatography systems marketed for the cannabis testing industry. Other commons CDS vendors include:
- Agilent Technologies' OpenLAB CDS
- Bruker Corporation's Compass Hystar
- H&A Scientific, Inc.'s PC/Chrom
- PerkinElmer Inc.'s Chromera
- Shimadzu Corporation's LabSolutions
- Waters Corporation's Empower 3
The use of seed-to-sale software is an emerging trend that is only tangentially related to laboratory testing of cannabis. Rather than at testing laboratories, seed-to-sale software is found at cultivation sites, production facilities, and dispensaries, and that software is typically designed to be able to integrate with testing laboratory or other software. The goal: create a complete record of transaction, from the grown plant to the lab, producer, and seller. This sort of tracking is mandated in various ways by many U.S. states with legalization laws. "It’s there to prevent the diversion of marijuana, which the federal government still lists as a Schedule I substance, the most dangerous class of drugs," wrote Daniel Rothberg of the Las Vegas Sun in December 2015. "Tracking also ensures product safety, assists with audits and helps facilitate recalls." This type of software is able to track plant yields, attempted theft or diversion, patient preferences, extraction methods, batch weights, and various financial statistics for analysis.
Seed-to-sale software vendors
The following vendors are a representative sample of those who offer a seed-to-sale system for the cannabis industry:
- Ample Organics, Inc. - Ample Organics
- Bio-Tech Medical Software, Inc. - BioTrackTHC
- Chetu, Inc. - Custom software solutions
- Dauntless Software, Inc. - Dauntless Retail
- Far-From-Groove'N, Inc. dba Viridian Sciences - Viridian Sciences
- Flourish Software, LLC - Flourish
- Franwell, Inc. - Metrc
- Ghost Management Group, LLC - MMJMenu
- Green Bits, Inc. - Green Bits
- Grow One Software (US), LLC - Grow One
- KindManage, LLC - Agrisoft
- Motagistics, LLC - 4S
- Open Systems, Inc. - Process Pro
- Proteus Business Solutions, Inc. - PROTEUS420
- Pyrotree, Inc. - WebJoint
- SDY & Associates, LLC - LeafOps
- TheraCann International Corporation – TheraCannSYSTEM
- Trellis Solutions, Inc. - Trellis
- WeedTraQR, LLC - WeedTraQR
Future of cannabis regulation, testing, and market trends
What is the future of cannabis regulation, testing and the associated market? The following, is taken from Chapter 5 of Past, Present, and Future of Cannabis Laboratory Testing and Regulation in the United States on LIMSwiki. Five days later, U.S. Attorney General Jeff Sessions continued to send pessimistic signals, stating he was "dubious about marijuana," and that "[w]e have a responsibility to use our best judgment ... and my view is we don’t need to be legalizing marijuana." Several days later, seemingly in response to both Spicer's and Sessions' comments, 11 U.S. senators sent a letter to Sessions asking him to keep in mind the President's campaign promises of letting states decide their own fate on legalization efforts. Encouraging responses to these and other requests (e.g., rescheduling, expanded grow operations, expanded research) remain elusive, however.
Until effective and demonstrable policy change takes place in the U.S. federal government concerning marijuana, researchers, doctors, patients, laboratory personnel and entrepreneurs will have to keep fighting uncertainty and a convoluted patchwork of state and federal regulations. More certain is mounting evidence that a growing majority of U.S. voters believe the federal government should not be enforcing its laws in such states: 64 percent agreed on this in 2012, rising to 71 percent in 2017. Despite such support, it may largely be up to the states in the future to twist the arm of the federal government. Legal representatives at Thompson Coburn expressed this idea well in a blog post in November 2016:
The cannabis industry may have to consider forcing the federal hand by providing credible data on the safety of cannabis as it was invited to do in the DEA decision, in addition to the continuing to support the groundswell of approval at the state level. At some point, in the near future, the state regulatory position and the federal position will have to be reconciled. The industry can and should prompt that reconciliation by a clear united message to federal lawmakers. Without that, it remains unlikely that agencies, such as the FDA, will change its position on cannabis. A lack of change will inhibit market growth and prevent the cannabis industry from reaching its potential.
Overall, the general national mood of acceptance and advocacy, coupled with the clear, detailed state-level implementation of rigorous controls, and recognition of the abundant and dynamic community of cannabis-related businesses (e.g. growing equipment, packaging, design, marketing, and yes, laboratory testing) may all contribute to the fact that as yet the US federal government has not chosen to attack state-legal enterprises.
The obvious issue with expanding research and testing on cannabis and of its safety is acquiring the product within a legal framework and a reasonable time frame. As mentioned previously, the DEA has recognized the need for more federally approved growers than the NIDA center at the University of Mississippi (which came under fire in March 2017 for not testing its provided samples for mold and other contaminants in any standardized fashion), and in 2016 they began accepting applications for additional entities looking to grow marijuana for researchers. However, as of December 2018, no new growers have been federally approved. Additionally, complaints have been leveled at the University of Mississippi facility by researchers for not providing enough diversified samples that are more representative of what people are purchasing from dispensaries.
Assuming the Trump administration acts on campaign promises—and signs point to the administration at least being on spoken record of supporting medical marijuana and associated research—researchers may eventually have more options for acquiring research-quality cannabis in the future. This should in turn allow researchers a shot at more focused studies that provide efficacy and safety data related to the medical use of cannabis. In fact, this has been a goal of Dr. Susan Weiss, Division Director of Extramural Research at the National Institute on Drug Abuse (NIDA) for some time. In July 2016 testimony to the U.S. Judiciary Committee and in an April 2017 research paper published in The International Journal of Drug Policy, Weiss cautiously recognized and promoted the need for further evidence-based cannabis research, emphasizing both the healthy and detrimental effects evident so far in the plant and its constituents. She said of recent federal actions towards this goal:
Multiple agencies (NIH, ONDCP, DEA, and FDA) are working together to find ways to streamline the process to facilitate research while meeting international and legislative obligations under the Single Convention on Narcotic Drugs and the Controlled Substances Act. In addition to actions taken by the Department of Health and Humans Services to eliminate the Public Health Services (PHS) committee review for non-federally funded marijuana research, the DEA recently streamlined the administrative process for CBD research to allow researchers to obtain a waiver of the requirement for review of changes to an approved protocol in their DEA research registrations, and is attempting to address the marijuana diversity and product development concern by licensing additional manufacturers.
Another recent and significant body of research that may have future influence on cannabis research itself is a massive January 2017 cannabis literature review published by the National Academies of Sciences, Engineering, and Medicine. This 440-page report detailed the National Academies' findings after reviewing more than 10,700 abstracts related to cannabis. Among its final recommendations, the authors called for:
- public and private entities to fund and support a national cannabis research initiative that looks to fill key knowledge gaps;
- government agencies to develop research methods and standards that may act as a guide towards higher-quality cannabis research;
- government agencies, non-profit associations, and state and local health departments to fund and support efforts to improve federal, state, and local public health surveillance systems and efforts; and
- government, non-government, and industry entities to work together towards developing a report on existing regulatory barriers to research and how to overcome them.
However, some researchers such as Mayo Clinic psychiatrist and researcher Michael Bostwick have historically been less convinced that the barriers will fall—claiming federal entities shift too much focus on the detrimental effects and not enough on the potential benefits—and aren't optimistic about the direction the Trump administration will take. Despite this pessimism, predictions of substantial revenues in states where recreational marijuana is legalized or could be legalized persist. The latest national estimates by market research and analytics company New Frontier Data put the U.S. marijuana industry at $24 billion by 2025, with 255,000 total jobs by 2019. Yet entities such as the Denver-based Marijuana Policy Group and cannabis law firm Vicente Sederberg LLC preach caution when dealing with tax revenue estimates and economic projections in the U.S. cannabis market, pointing to CIBC World Markets' grossly inflated tax revenue estimate of $142 CAD ($106 USD) per resident in January 2016, an overshot of about 300 percent. "This is a fast-paced, changing market with varying different dynamics that have more to do based on governmental and regulatory dynamics than they do on consumer dynamics," said Vicente Sederberg's director of economics and research Andrew Livingston.
Indeed, current and future regulatory dynamics seem to be the biggest wildcards in making market-based predictions, with predicted tax and associated revenue estimates capable of both being significantly too high (by inadequately taking into account local and regional cultural and economic statuses) or too low (by not anticipating new states legalization efforts, research breakthroughs, or ties to other mainstream but related industries). Additionally, too much regulation can put a stranglehold on a state's cannabis program development—as it has done in Minnesota—causing related grow-ops and laboratories to take significant losses or even go out of business.
Finally, on a social level, the push by many to legalize marijuana and, by extension, push for beneficial changes in federal marijuana policy, has been driven even further by dramatic increase in use of and health consequences surrounding opioids in the United States. What's not clear is how effective a replacement cannabis would be. Dr. Weiss again provides context, this time in the February 2018 workshop Cannabis and the opioid crisis: A multidisciplinary review:
I think we need to be very circumspect in what we are expecting from cannabis with respect to the opioid epidemic. There is no doubt that there are many patients suffering from pain, and we do not have a lot of options to treat it, especially chronic pain. Moreover, the cannabinoid system has a lot of promise regarding analgesic potential and alternative medication approaches. Whether it is the plant, components of the plant, or other strategies to modify endocannabinoid function—these are all possibilities that we need to explore to both help abate the opioid crisis and treat patients with pain who continue to suffer.
From that same workshop, several additional insights were revealed:
- The National Academies' 2017 research recognizes "the classification of cannabis as a Schedule I substance [as something] that impedes the advancement of cannabis and cannabinoid research." Getting past that will require the federal government living up to its 2016 promise to expand approved grow-ops.
- Getting marijuana rescheduled is further challenged by the fact that an entire plant and its constituents are scheduled. Difficulties arise because when we talk about rescheduling marijuana, the question has to be asked: "Are you talking about a plant that is mostly THC, that is mostly CBD, that has unspecified different components in it?"
- A major question remains concerning "whether cannabinoids and opioids interact at a pharmacological level." To further study this, not only do well organized studies need to be designed, but also, as previously mentioned, access to quality samples and a willingness to see the benefit in such research is still required.
As of December 2018, the Marijuana Data Collection Act is still making its way through the House of Representatives. Citing many of the previously mentioned issues and more, the proposed bill asks for the National Academy of Sciences "to conduct and update biennially a study on the effects of State legalized marijuana programs," among other tasks. Specifically the research would look at revenue impacts, medicinal use and safety, correlation with opioid abuse, criminal justice impacts, and employment impacts. Whether or not this bill passes, one may argue that its intent is in line with the sentiment of representatives at Thompson Coburn: "forcing the federal hand by providing credible data on the safety of cannabis."
Lab testing Another forward-looking statement by Research and Markets in March 2017 suggested the cannabis testing market across the globe could be valued at $1.4 billion by 2021, affected positively by legalization of medical cannabis, laboratory growth, and information technology adoption, negatively by analytical instruments' high costs and a "dearth of skilled professionals." A more conservative number was offered by Coherent Market Insights in July 2018, suggesting a global market at $1.5 billion by 2026.
As for advances in cannabis lab testing, Kuzdzal et al. of Shimadzu envision a future where improvements in standardization, quality control, and research will shift what is tested and how it's tested:
The cannabis industry and cannabis testing are in their infancies. As the need for better quality control continues and standardization is introduced, it is likely that lower limits for the various cannabis contaminants will be established and regulations will be introduced. Mass spectrometry will likely play a greater role in quantitation as detection levels are lowered and confirmatory tests are required. The health benefits of terpenes present in cannabis will also provide a fertile area of scientific research. CBD, CBG and other compounds appear to have a synergistic relationship with each other as well as with various THC forms and terpenes. This field needs much more investigation to determine mechanisms of action, bioavailability and health benefits.
Lab testing of cannabis should continue to provide more exact and useful results as methods and standards continue to evolve. Disparity of results between two labs for the same sample are continuing to narrow as states increasingly add testing requirements to their cannabis legislature. Those testing requirements are increasingly based off a growing body of recommendations, guidance, and standards developed by the likes of the Americans for Safe Access Foundation (ASAF), American Herbal Pharmacopoeia (AHP), American Herbal Products Association (AHPA), Association of Official Agricultural Chemists (AOAC), American Oil Chemists' Society (AOCS), and the Association of Public Health Laboratories. Proficiency tests such as the Emerald Test, which allows multiple labs to test an anonymous sample and compare results, should also continue to drive improved performance from cannabis testing labs.
Another potential trend to keep an eye on with these testing laboratories: consolidation. Currently there aren't a lot of data as to the extent that consolidation has affected the number of cannabis testing labs or how they operate; the industry is arguably still in its infancy. Regardless, mentions in press and practical examples demonstrate that consolidation is a real concern for the industry, if not now in the future. Suggestion of such came from Steep Hill Halent's CEO David Lampach in late 2013, anticipating "huge consolidation in general and fewer companies as a result." The previously mentioned GreenWave Advisors as well as CannaSafe Analytics and Kramer Holcomb Sheik have also lent their voices to this idea in recent years. Startup costs also tend to favor existing labs who merely extend their services as opposed to brand-new labs who have to acquire premises, equipment (and cannabis testing requires a selection - unlike a small clinical diagnostics lab, for instance, which may be able to get away with a single chem analyzer initially), software (LIMS), hire staff, get licensed, etc.
- Biros, A.G. (11 January 2017). "Analyzing The Emerald Test Results: Cannabis Labs Making Progress". Cannabis Industry Journal. https://www.cannabisindustryjournal.com/feature_article/analyzing-the-emerald-test-results-cannabis-labs-making-progress.
- Demski, N. (September 2018). "Testing the Waters: Is My Cannabis Safe to Consume?". Terpenes and Testing Magazine. https://terpenesandtesting.com/category/testing/water-activity-testing-cannabis.
- Oberhill, D., Goldman, S. (May 14, 2018). "Understanding Water Activity". Marijuana Venture Magazine. https://www.marijuanaventure.com/understanding-water-activity.
- Saman, A. (22 May 2016). "18 GMP Cannabis defintions you need to know". HempHacker.com. http://hemphacker.com/cgmp-definitions-for-the-cannabis-industry-21-cfr-part-210/.
- Association of Public Health Laboratories (May 2016). "Guidance for State Medical Cannabis Testing Programs" (PDF). pp. 35. https://www.aphl.org/aboutAPHL/publications/Documents/EH-Guide-State-Med-Cannabis-052016.pdf. Retrieved 01 February 2017.
- "California Cannabis Portal". State of California. 2018. https://cannabis.ca.gov/.
- Cassiday, L. (October 2016). "The Highs and Lows of Cannabis Testing". INFORM. American Oil Chemists' Society. https://www.aocs.org/stay-informed/read-inform/featured-articles/the-highs-and-lows-of-cannabis-testing-october-2016. Retrieved 07 December 2018.
- Unger, P.; Brauninger, R.; Hudalla, C. et al. (December 2014). "Standards for Cannabis Testing Laboratories". Cannabis Safety Institute. http://cannabissafetyinstitute.org/wp-content/uploads/2015/01/Standards-for-Cannabis-Testing-Laboratories.pdf.
- Wurzer, J. (May 2016). "Applications of Cannabis Testing". SC Laboratories, Inc. http://www.medicinalgenomics.com/wp-content/uploads/2016/05/wurzer-CannMed2016.pdf.
- "Reference Methods for the Testing of Retail and Medical Marijuana". Colorado Department of Public Health and Environment. https://www.colorado.gov/pacific/sites/default/files/Marijuana%20Testing%20Method%20Reference%20Library.pdf.
- Radwan, M.M.; ElSohly, M.A.; El-Alfy, A.T. et al. (2015). "Isolation and pharmacological evaluation of minor cannabinoids from high-potency Cannabis sativa". Journal of Natural Products 78 (6): 1271-6. doi:10.1021/acs.jnatprod.5b00065. PMC PMC4880513. PMID 26000707. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC4880513.
- Kuzdzal, S.; Clifford, R.; Winkler, P.; Bankert, W. (December 2017). "A Closer Look at Cannabis Testing" (PDF). Shimadzu Corporation. https://www.ssi.shimadzu.com/sites/ssi.shimadzu.com/files/Industry/Literature/Shimadzu_Whitepaper_Emerging_Cannabis_Industry.pdf. Retrieved 07 December 2018.
- Mudge, E.M.; Murch, S.J.; Brown, P.N. (2018). "Chemometric Analysis of Cannabinoids: Chemotaxonomy and Domestication Syndrome". Scientific Reports 8: 13090. doi:10.1038/s41598-018-31120-2.
- World Health Organization (2016). Hall, W.; Renström, M.; Poznyak, V. ed. The health and social effects of nonmedical cannabis use. World Health Organization. pp. 95. ISBN 978921510240. http://www.who.int/substance_abuse/publications/cannabis/en/.
- Rahn, B. (22 January 2014). "Cannabinoids 101: What Makes Cannabis Medicine?". Leafly - Cannabis 101. Leafly Holdings, Inc. https://www.leafly.com/news/cannabis-101/cannabinoids-101-what-makes-cannabis-medicine. Retrieved 03 February 2017.
- Kuzdzal, S.; Lipps, W. (2015). "Unraveling the Cannabinome". The Analytical Scientist (0915). https://theanalyticalscientist.com/issues/0915/unraveling-the-cannabinome/. Retrieved 19 January 2017.
- Rahn, B. (09 October 2014). "Understanding Cannabis Testing: A Guide to Cannabinoids and Terpenes". Leafly - Cannabis 101. Leafly Holdings, Inc. https://www.leafly.com/news/cannabis-101/understanding-cannabis-testing. Retrieved 03 February 2017.
- "delta-8-tetrahydrocannabinol". NCI Drug Dictionary. National Institutes of Health, National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-drug?cdrid=485262. Retrieved 08 February 2017.
- Habib, R.; Finighan, R.; Davenport, S. (24 August 2013). "Testing for Psychoactive Agents" (PDF). BOTEC Analysis Corp. http://lcb.wa.gov/publications/Marijuana/BOTEC%20reports/1c-Testing-for-Psychoactive-Agents-Final.pdf. Retrieved 08 February 2017.
- "Tests Offered". CMT Laboratories. http://www.cmtlaboratory.com/test-services/tests-offered/. Retrieved 08 February 2017.
- "Terpene Profiling Services". The Werc Shop. http://thewercshop.com/services/terpene-profiling-services/. Retrieved 08 February 2017.
- Andre, C.M.; Hausman, J.-F.; Guerriero, G. (2016). "Cannabis sativa: The plant of the thousand and one molecules". Frontiers in Plant Medicine 7: 19. doi:10.3389/fpls.2016.00019. PMC PMC4740396. PMID 26870049. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC4740396.
- Wachsberger, K. (02 February 2016). "Terpene Testing: The future of Cannabis is here". Bloom Blog. Bloom City Club. http://www.bloomcityclub.com/terpine-testing-the-future-of-cannabis-is-here/. Retrieved 08 February 2017.
- Borel, B. (31 August 2015). "The Wild West of Marijuana Pesticides". The Atlantic. The Atlantic Monthly Group. https://www.theatlantic.com/health/archive/2015/08/pot-marijuana-pesticide-legalization/401771/. Retrieved 09 February 2017.
- Zhang, S. (07 August 2015). "Nobody Knows What to Do About Pesticides in Legal Marijuana". Wired. Condé Nast. https://www.wired.com/2015/08/nobody-knows-pesticides-legal-marijuana//. Retrieved 09 February 2017.
- Farrer, D.G. (December 2015). "Technical Report: Oregon Health Authority’s Process to Determine Which Types of Contaminants to Test for in Cannabis Products, and Levels for Action" (PDF). Oregon Health Authority. https://public.health.oregon.gov/PreventionWellness/marijuana/Documents/oha-8964-technical-report-marijuana-contaminant-testing.pdf. Retrieved 09 February 2017.
- Romano, L.L.; Hazekamp, A. (2013). "Cannabis oil: Chemical evaluation of an upcoming cannabis-based medicine" (PDF). Cannabinoids 1 (1): 1–11. http://www.stcm.ch/en/files/hazekamp_cann-oil_2013.pdf.
- Peach, J.; Eastoe, J. (2014). "Supercritical carbon dioxide: A solvent like no other". Journal of Organic Chemistry 10: 1878-95. doi:10.3762/bjoc.10.196. PMC PMC4168859. PMID 25246947. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC4168859.
- "<467> Residual Solvents" (PDF). United States Pharmacopeia and The National Formulary. United States Pharmacopeial Convention. 01 July 2007. https://www.usp.org/sites/default/files/usp_pdf/EN/USPNF/generalChapter467Current.pdf. Retrieved 09 February 2017.
- Bureau of Healthcare Safety and Quality (12 February 2016). "Response to Public Comments" (PDF). Massachusetts Department of Public Health. http://www.mass.gov/eohhs/docs/dph/quality/medical-marijuana/lab-protocols/external-comment-response-020416-final.pdf. Retrieved 14 February 2017.
- Daley, P.; Lampach, D.; Sguerra, S. (12 September 2013). "Testing Cannabis for Contaminants" (PDF). BOTEC Analysis Corp. http://lcb.wa.gov/publications/Marijuana/BOTEC%20reports/1a-Testing-for-Contaminants-Final-Revised.pdf. Retrieved 09 February 2017.
- "UC Davis study finds mold, bacterial contaminants in medical marijuana samples". UC Davis. 07 February 2017. http://www.ucdmc.ucdavis.edu/publish/news/newsroom/11791. Retrieved 10 February 2017.
- Kennard, M. (02 June 2016). "You are Probably Smoking Mouldy Weed - Why Does Quality Assurance Matter?". Populace. Tantalus Labs. https://tantaluslabs.com/populace/you-are-probably-smoking-mouldy-weed-why-does-quality-assurance-matter/. Retrieved 10 February 2017.
- "Microbiological study of Cannabis samples". Fundación CANNA. 2014. http://www.fundacion-canna.es/en/microbiological-study-cannabis-samples. Retrieved 10 February 2017.
- McPartland, J.M. (2013). "Chapter 30: Contaminants and Adulterants in Herbal Cannabis". In Russo, E.B.. Cannabis and Cannabinoids: Pharmacology, Toxicology, and Therapeutic Potential. Routledge. pp. 478. ISBN 9781136614934. https://books.google.com/books?id=qH-2Lj9x7L4C&pg=PT457&lpg=PT457.
- Rough, Lisa. "Leafly’s State-by-State Guide to Medical Cannabis Testing Regulations". Leafly - Industry. Leafly Holdings, Inc. https://www.leafly.com/news/industry/leaflys-state-by-state-guide-to-cannabis-testing-regulations.
- "State Info". NORML Foundation. 2017. http://norml.org/states. Retrieved 10 April 2017.
- Rigdon, A. (12 May 2016). "Extraction Method for Cannabinoid Analysis in Edibles: Too Much of a Good Thing". ChromaBLOGraphy. Restek Corporation. http://blog.restek.com/?p=25790. Retrieved 16 February 2017.
- Codex Alimentarius Commission. "CAC/GL 50-2004 General Guidelines on Sampling" (PDF). pp. 69. http://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fcodex%252FStandards%252FCAC%2BGL%2B50-2004%252FCXG_050e.pdf. Retrieved 15 February 2017.
- Bureau of Health Care Safety and Quality (05 February 2016). "Protocol for Sampling and Analysis of Finished Medical Marijuana Products and Marijuana-Infused Products for Massachusetts Registered Medical Marijuana Dispensaries" (PDF). Massachusetts Department of Public Health. pp. 25. http://www.mass.gov/eohhs/docs/dph/quality/medical-marijuana/lab-protocols/finished-mmj/final-revised-mdph-mmj-mips-protocol.pdf. Retrieved 17 February 2017.
- "Why 0.877?". Confidence Analytics. 10 February 2016. http://conflabs.com/why-0-877/. Retrieved 16 February 2017.
- Rigdon, A. (29 July 2015). "Accurate Quantification of Cannabinoid Acids by GC – Is it Possible?". ChromaBLOGraphy. Restek Corporation. http://blog.restek.com/?p=14961. Retrieved 16 February 2017.
- Rigdon, A. (09 September 2015). "Accurate Quantification of Cannabinoid Acids and Neutrals by GC – Derivatives without Calculus". ChromaBLOGraphy. Restek Corporation. http://blog.restek.com/?p=15135. Retrieved 16 February 2017.
- Division of Environmental Health Sciences, Laboratory of Organic Analytical Chemistry (03 November 2015). "Measurement of Phytocannabinoids using HPLC-PDA, NYS DOH MML-300" (PDF). New York State Department of Health. pp. 34. https://www.wadsworth.org/sites/default/files/WebDoc/576578963/MML-300-01.pdf. Retrieved 15 February 2017.
- Leghissa, A.; Smuts, J.; Qiu, C. et al. (2018). "Detection of cannabinoids and cannabinoid metabolites using gas chromatography with vacuum ultraviolet spectroscopy". SSC Plus 1 (1): 37–42. doi:10.1002/sscp.201700005.
- "Cannabis Testing: Quality You Can Trust" (PDF). Sigma-Aldritch Co. LLC. 2016. http://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma-Aldrich/General_Information/1/cannabis-testing.pdf. Retrieved 15 February 2017.
- Adams, T.; Bertone, M. (30 November 2016). "Near Infrared, GC and HPLC Applications in Cannabis Testing". Cannabis Industry Journal. Innovative Publishing Co. LLC. https://www.cannabisindustryjournal.com/column/near-infrared-gc-and-hplc-applications-in-cannabis-testing/. Retrieved 15 February 2017.
- Herring, T. (29 December 2016). "Can HPLC-UV Be Used For Terpenes Analysis In Cannabis?". ChromaBLOGraphy. Restek Corporation. http://blog.restek.com/?p=33071. Retrieved 15 February 2017.
- Hodgson, A.; Cochran, J. (12 February 2018). "Vacuum Ultraviolet Spectroscopy: A New Tool for Gas Chromatography Analysis of Terpenes in Flavours and Fragrances". LC GC 14 (2): 12–16. http://www.chromatographyonline.com/vacuum-ultraviolet-spectroscopy-new-tool-gas-chromatography-analysis-terpenes-flavours-and-fragrance.
- "Cannabis Testing Laboratory Solutions" (PDF). Shimadzu Corporation. https://www.ssi.shimadzu.com/products/literature/life_science/shimadzu_cannabis_brochure.pdf. Retrieved 14 February 2017.
- CEM Corporation (25 July 2018). "Analyzing Pesticide Residue of Cannabis". AZO Materials. AZoNetwork. https://www.azom.com/article.aspx?ArticleID=16383. Retrieved 15 November 2018.
- DePalma, A. (10 September 2018). "Challenges of Cannabis Contaminant Testing". Lab Manager. LabX Media Group. https://www.labmanager.com/insights/2018/09/challenges-of-cannabis-contaminant-testing. Retrieved 15 November 2018.
- LCGC (August 2016). "Real-World Chromatography Applications: Current Trends in Cannabis, Environmental, Food, Pharmaceutical, and Biopharmaceutical Analysis" (PDF). LCGC North America 2016-2017 Annual Industry Trends and Directory Issue. UBM. pp. 584–7. http://images2.advanstar.com/PixelMags/lcgc-na/pdf/2016-08-bg.pdf. Retrieved 15 November 2018.
- Kowalski, J.; Dahi, J.H.; Rigdon, A. et al. (2017). "Evaluation of Modified QuEChERS for Pesticide Analysis in Cannabis". LC GC 35 (5): 8–22. http://www.chromatographyonline.com/evaluation-modified-quechers-pesticide-analysis-cannabis.
- Winkler, P.C.; Egerton, D.; Butt, C. et al. (06 June 2018). "Pesticide Testing for the Cannabis Industry: The Importance of LC-MS/MS for Obtaining Accurate Results in a Complex Matrix". Labcompare Featured Articles. CompareNetworks, Inc. https://www.labcompare.com/10-Featured-Articles/338461-Pesticide-Testing-for-the-Cannabis-Industry-The-Importance-of-LC-MS-MS-for-Obtaining-Accurate-Results-in-a-Complex-Matrix/. Retrieved 15 November 2018.
- Jordan, R.; Asanuma, L.; Miller, D.; Macherone, A. (19 June 2018). A Comprehensive Approach to Pesticide Residue Analysis in Cannabis. 1. UBM. http://www.cannabissciencetech.com/dispersive-solid-phase-extraction-dspe/comprehensive-approach-pesticide-residue-analysis-cannabis.
- "Residue Analytical Methods (RAM)". United States Environmental Protection Agency. 20 February 2016. https://archive.epa.gov/pesticides/methods/rammethods/web/html/ram12b.html. Retrieved 14 February 2017.
- "Pesticide Analytical Manual (PAM)". United States Food and Drug Administration. 07 June 2015. http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006955.htm. Retrieved 14 February 2017.
- Poceva Panovska, A.; Acevska, J.; Stefkov, G. et al. (2016). "Optimization of HS-GC-FID-MS Method for Residual Solvent Profiling in Active Pharmaceutical Ingredients Using DoE". Journal of Chromatographic Science 54 (2): 103–11. doi:10.1093/chromsci/bmv123. PMID 26290585.
- L'Heureux, M.L. (20 April 2018). "Advancing Chromatography Methods for Cannabis Analysis". Cannabis Science and Technology. UBM.
- Boyle, R.; Ferrell, E. (21 September 2018). "Selecting Microwave Digestion Technology for Measuring Heavy Metals in Cannabis Products". Cannabis Science and Technology 1 (3). http://www.cannabissciencetech.com/metals/selecting-microwave-digestion-technology-measuring-heavy-metals-cannabis-products.
- Davis, D.; Long, K.; Masone, J.; Firmin, P. (August 2015). "Analysis of "The Big Four" Heavy Metals in Cannabis by USN-ICP-OES" (PDF). Shimadzu Corporation. http://www.ssi.shimadzu.com/products/literature/aas/ssi-icp-002.pdf. Retrieved 14 February 2017.
- Thompson III, G.R.; Tuscano, J.M.; Dennis, M. et al. (2017). "A microbiome assessment of medical marijuana". Clinical Microbiology and Infection: S1198-743X(16)30605-X. doi:10.1016/j.cmi.2016.12.001. PMID 27956269.
- L'Heureux, M.L. (06 August 2018). "Testing for Pesticides and Mycotoxins in Cannabis: How to Meet Regulatory Requirements". Cannabis Science and Technology. UBM.
- "<561> Articles of Botanical Origin" (PDF). United States Pharmacopeia and The National Formulary. United States Pharmacopeial Convention. 01 July 2007. https://hmc.usp.org/sites/default/files/documents/HMC/GCs-Pdfs/c561.pdf. Retrieved 15 February 2017.
- Cundell, T. (31 July 2015). "Microbiological attributes of powdered cannabis". American Pharmaceutical Review. CompareNetworks, Inc. http://www.americanpharmaceuticalreview.com/Featured-Articles/177487-Microbiological-Attributes-of-Powdered-Cannabis/. Retrieved 15 February 2017.
- "CALIFORNIA CODE OF REGULATIONS, TITLE 16, DIVISION 42. BUREAU OF CANNABIS CONTROL, Chapter 6, part 5726 Certificate of Analysis (COA)". California Code of Regulations. California Bureau of Cannabis Control. https://cannabis.ca.gov/wp-content/uploads/sites/13/2019/01/Order-of-Adoption-Clean-Version-of-Text.pdf. Retrieved 5 February 2019.
- Pennsylvania Department of Health (24 December 2016). "Title 28 - Health and Safety, Department of Health - 28 Pa. Code Ch. 1171" (PDF). Pennsylvania Bulletin 46 (52): 8036–8041. http://www.health.pa.gov/My%20Health/Diseases%20and%20Conditions/M-P/MedicalMarijuana/Documents/Chapter%201171%20Laboratories%201-26-17.pdf.
- "Certificate of Analysis - Sample: Godzilla" (PDF). Cannabis Chronicles. 07 July 2014. http://cannabis-chronicles.com/wp-content/uploads/Godzilla.pdf. Retrieved 16 February 2017.
- "Current Test Results". Analytical 360, LLC. http://analytical360.com/testresults. Retrieved 16 February 2017.
- Hydrio (August 2016). "Can you help me analyze lab reports of cannabis oil?". Beyond Chronic: Ask Old Hippie. http://beyondchronic.com/question/can-you-help-me-analyze-lab-reports-of-cannabis-oil/. Retrieved 16 February 2017.
- McKenna, M. (18 June 2015). "Setting Up Your Cannabis Lab for Potency Testing". SlideShare. GenTech. http://www.slideshare.net/GenTechScientific/ica2015-cannabis-presentation. Retrieved 16 February 2017.
- Public Health Division. "Reporting Requirements for Tracking Medical Marijuana". Oregon Health Authority. https://public.health.oregon.gov/DiseasesConditions/ChronicDisease/MedicalMarijuanaProgram/Pages/reporting.aspx. Retrieved 16 February 2017.
- "Chapter 314-55 WAC: Marijuana Licenses, Application Process, Requirements, and Reporting". Washington Administrative Code. Washington State Legislature. 16 November 2016. http://apps.leg.wa.gov/wac/default.aspx?cite=314-55&full=true. Retrieved 16 February 2017.
- Milman, B.L. (2010). "Chapter 2: Techniques and Methods of Identification". Chemical Identification and its Quality Assurance. Springer Berlin Heidelberg. pp. 23–39. doi:10.1007/978-3-642-15361-7_2. ISBN 9783642153617.
- Taylor, M. (23 June 2015). "Cannabis Testing Opens Up a Whole New Market". Laboratory Equipment. Advantage Business Media. http://www.laboratoryequipment.com/article/2015/06/cannabis-testing-opens-whole-new-market. Retrieved 17 February 2017.
- "Laboratory Informatics". virtualinformatics.com. 09 April 2011. Archived from the original on 25 April 2015. http://web.archive.org/web/20150425070143/http://virtualinformatics.com/content/Laboratory_informatics.htm. Retrieved 17 February 2017.
- Skobelev, D.O.; Zaytseva, T.M.; Kozlov, A.D. et al. (2011). "Laboratory information management systems in the work of the analytic laboratory". Measurement Techniques 53 (10): 1182–1189. doi:10.1007/s11018-011-9638-7.
- Biros, A.G. (23 October 2015). "Using LIMS in Cannabis Laboratories". Cannabis Industry Journal. Innovative Publishing Co. LLC. https://www.cannabisindustryjournal.com/feature_article/using-lims-in-cannabis-laboratories/. Retrieved 21 February 2017.
- "LIMS for Managing Cannabis Testing". Promium, LLC. https://www.promium.com/main/element-lims-cannabis. Retrieved 21 February 2017.
- "PharmWare". PharmLabs LLC. http://www.pharmware.net/. Retrieved 21 February 2017.
- "LabLynx LIMS - Cannabis". LabLynx, Inc. 20 January 2017. http://www.lablynxpress.com/index.php?title=LabLynx_LIMS_-_Cannabis. Retrieved 21 February 2017.
- Purschke, K.; Heinl, S.; Lerch, O. et al. (2016). "Development and validation of an automated liquid-liquid extraction GC/MS method for the determination of THC, 11-OH-THC, and free THC-carboxylic acid (THC-COOH) from blood serum". Analytical and Bioanalytical Chemistry 408 (16): 4379-88. doi:10.1007/s00216-016-9537-5. PMC PMC4875941. PMID 27116418. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC4875941.
- Albertini, T.; Caruso, A. (2015). "Determination of Tetrahydrocannabinol (THC) and Its Main Metabolites Using GC Triple Quadrupole Mass Spectrometry" (PDF). Thermo Fisher Scientific. http://tools.thermofisher.com/content/sfs/posters/PO-GC-MS-THC-Metabolites-Triple-Quad-EN.pdf. Retrieved 17 February 2017.
- Layton, C.; Reuter, W.M. (23 January 2017). "Analysis of Cannabinoids in Hemp Seed Oils by HPLC Using PDA Detection" (PDF). PerkinElmer, Inc. https://www.perkinelmer.com/lab-solutions/resources/docs/APP_Analysis-of-Cannabinoids-in-Hemp-Seed-Oils-by-HPLC-012317_01.pdf. Retrieved 17 February 2017.
- Davies, A.N. (12 April 2016). "Central spectroscopic data systems: Why are chromatographers so much better equipped?". Spectroscopy Europe. John Wiley & Sons Ltd; IM Publications LLP. http://www.spectroscopyeurope.com/articles/tony-davies-column/3676-central-spectroscopic-data-systems-why-are-chromatographers-so-much-better-equipped. Retrieved 17 February 2017.
- "Waters Empower Shimadzu GC Driver Version 2". Shimadzu Scientific Instruments. http://www.ssi.shimadzu.com/products/product.cfm?product=gcdriver. Retrieved 17 February 2017.
- Rothberg, D. (29 December 2015). "Software Firms Benefit from Government’s Seed-to-Sale Marijuana Tracking". Government Technology. e.Republic, Inc. http://www.govtech.com/state/Software-Firms-Benefit-from-Governments-Seed-to-Sale-Marijuana-Tracking.html. Retrieved 21 February 2017.
- Smyth, H. (21 June 2016). "Track and Trace vs. Seed to Sale". MJ Freeway Blog. MJ Freeway, LLC. https://mjfreeway.com/blog/track-and-trace-vs-seed-to-sale. Retrieved 21 February 2017.
- Kumar, A.; Hotokainen, R. (23 February 2017). "Trump administration plans crackdown on recreational marijuana". McClatchy DC. http://www.mcclatchydc.com/news/nation-world/national/article134608704.html. Retrieved 02 March 2017.
- Wheeler, L. (28 February 2017). "Sessions: 'We don't need to be legalizing marijuana'". The Hill. Capitol Hill Publishing Corp. http://thehill.com/regulation/administration/321525-sessions-we-dont-need-to-be-legalizing-marijuana. Retrieved 02 March 2017.
- Hotokainen, R. (02 March 2017). "11 senators call on Trump team to allow sale of recreational marijuana". McClatchy DC. http://www.mcclatchydc.com/news/politics-government/congress/article135996463.html. Retrieved 02 March 2017.
- Holden, D. (29 August 2018). "Inside The Trump Administration’s Secret War On Weed". BuzzFeed News. BuzzFeed, Inc. https://www.buzzfeednews.com/article/dominicholden/trump-secret-committee-anti-marijuana?link_id=1&can_id=b87b7ccc1b21da88de179c339ca74652. Retrieved 15 November 2018.
- Laslo, M. (30 August 2018). "Why Is the White House Contradicting Trump’s Pot Policy?". Rolling Stone. Rolling Stone, LLC. https://www.rollingstone.com/politics/politics-news/why-is-the-white-house-contradicting-trumps-pot-policy-717524/. Retrieved 15 November 2018.
- Laslo, M. (05 October 2018). "Congress Is Getting Frustrated With the White House’s Pot Policy". Rolling Stone. Rolling Stone, LLC. https://www.rollingstone.com/politics/politics-news/weed-pot-policy-white-house-congress-trump-733285/. Retrieved 15 November 2018.
- Newport, F. (10 December 2012). "Americans Want Federal Gov't Out of State Marijuana Laws". Gallup, Inc. http://www.gallup.com/poll/159152/americans-federal-gov-state-marijuana-laws.aspx. Retrieved 02 March 2017.
- "Republicans Out Of Step With U.S. Voters On Key Issues, Quinnipiac University National Poll Finds; Most Voters Support Legalized Marijuana". Quinnipiac University. 23 February 2017. https://poll.qu.edu/national/release-detail?ReleaseID=2432. Retrieved 02 March 2017.
- Romza-Kutz, D.; Roth V., F. (15 August 2016). "The silver lining in the DEA’s refusal to reclassify cannabis". Tracking Cannabis. Thompson Coburn LLP. http://www.thompsoncoburn.com/insights/blogs/tracking-cannabis/post/2016-08-15/the-silver-lining-in-the-dea-s-refusal-to-reclassify-cannabis. Retrieved 25 January 2017.
- Hellerman, C. (08 March 2017). "Scientists say the government’s only pot farm has moldy samples — and no federal testing standards". PBS NewsHour. NewsHour Productions, LLC. http://www.pbs.org/newshour/updates/scientists-say-governments-pot-farm-moldy-samples-no-guidelines/. Retrieved 15 March 2017.
- "Applications To Become Registered Under the Controlled Substances Act To Manufacture Marijuana To Supply Researchers in the United States". Federal Register 81 (156): 53846–8. 12 August 2016. https://www.federalregister.gov/documents/2016/08/12/2016-17955/applications-to-become-registered-under-the-controlled-substances-act-to-manufacture-marijuana-to. Retrieved 27 January 2017.
- Piomelli, D.; Weiss, S.; Boyd, G. et al. (2018). "Cannabis and the Opioid Crisis". Cannabis and Cannabinoid Research 3 (1): 108-16. doi:10.1089/can.2018.29011.rtl. PMC PMC5931647. PMID 29789812. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC5931647.
- "Trump on Marijuana Policy". Marijuana Policy Project. 12 February 2017. https://www.mpp.org/federal/trump-marijuana-policy/. Retrieved 03 March 2017.
- Weiss, S.R.B. (13 July 2016). "Testimony from Susan R.B. Weiss, Ph.D. on The State of the Science on the Therapeutic Potential of Marijuana and Cannabinoids before Judiciary Committee". ASL Testimony. U.S. Department of Health & Human Services. https://www.hhs.gov/about/agencies/asl/testimony/2016-09/the-state-of-the-science-on-the-therapeutic-potential-of-marijuana-and-cannabinoids/index.html. Retrieved 25 January 2017.
- Weiss, S.R.B.; Howlett, K.D.; Baler, R.D. (2017). "Building smart cannabis policy from the science up". International Journal of Drug Policy 42: 39–49. doi:10.1016/j.drugpo.2017.01.007. PMC PMC5404989. PMID 28189459. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=PMC5404989.
- National Academies of Sciences, Engineering, and Medicine (12 January 2017). "The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research". The National Academies Press. pp. 440. doi:10.17226/24625. http://nationalacademies.org/hmd/reports/2017/health-effects-of-cannabis-and-cannabinoids.aspx. Retrieved 03 March 2017.
- Grant, B. (23 January 2017). "Marijuana Research Still Stymied by Federal Laws". The Scientist. LabX Media Group. http://www.the-scientist.com/?articles.view/articleNo/48122/title/Marijuana-Research-Still-Stymied-by-Federal-Laws/. Retrieved 03 March 2017.
- Morris, C. (21 October 2016). "The next big billion-dollar cannabis markets investors are rushing to". CNBC. http://www.cnbc.com/2016/10/21/the-next-big-billion-dollar-cannabis-markets-investors-are-rushing-to.html. Retrieved 03 March 2017.
- Thomas, J.R. (07 February 2017). "Big pot of money waiting if CT legalizes marijuana, analysts say". The CT Mirror. The Connecticut News Project. http://ctmirror.org/2017/02/07/big-pot-of-money-waiting-if-ct-legalizes-marijuana-analysts-say/. Retrieved 03 March 2017.
- Houghton, S. (14 February 2017). "Town Manager: Marijuana Shops Could Boost Tax Revenue". The Mashpee Enterprise. Enterprise Newspapers. http://www.capenews.net/mashpee/news/town-manager-marijuana-shops-could-boost-tax-revenue/article_c27b9b71-fb63-52de-bc24-fda320f38a32.html. Retrieved 03 March 2017.
- Wallace, A. (22 February 2017). "Report: America’s marijuana industry headed for $24 billion by 2025". The Cannabist. The Denver Post. http://www.thecannabist.co/2017/02/22/report-united-states-marijuana-sales-projections-2025/74059/. Retrieved 03 March 2017.
- Wallace, A. (22 December 2016). "What legal states need to know about sketchy pot tax predictions". The Cannabist. The Denver Post. http://www.thecannabist.co/2016/12/22/marijuana-sales-pot-taxes-colorado-estimates-projections/69831/. Retrieved 03 March 2017.
- Potter, K. (12 August 2016). "Big losses for Minn. medical marijuana providers". MPR News. Minnesota Public Radio. http://www.mprnews.org/story/2016/08/12/big-losses-for-minn-medical-marijuana-providers. Retrieved 03 March 2017.
- Bradford, A.S.; Abraham, A.; Adams, G.B. (2018). "Opioid Death Rate Acceleration in Jurisdictions Legalizing Marijuana Use—Reply". JAMA Internal Medicine 178 (9): 1281–2. doi:10.1001/jamainternmed.2018.3891.
- Goldman, H. (13 July 2018). "New York Health Officials See Marijuana as an Alternative to Opioids". Bloomberg. https://www.bloomberg.com/news/articles/2018-07-13/n-y-health-officials-see-marijuana-as-an-alternative-to-opioids. Retrieved 15 November 2018.
- Sukel, K. (01 May 2018). "Could Cannabis Legalization Help Ease the Opioid Crisis?". Pain Research Forum. International Association for the Study of Pain. https://www.painresearchforum.org/news/95694-could-cannabis-legalization-help-ease-opioid-crisis. Retrieved 15 November 2018.
- Gabbard, T. (24 July 2018). "H.R.6495 - Marijuana Data Collection Act". Congress.gov. https://www.congress.gov/bill/115th-congress/house-bill/6495/text. Retrieved 15 November 2018.
- Angell, T. (24 July 2018). "Federal Report On Marijuana Legalization Required Under New Bill". Forbes. https://www.forbes.com/sites/tomangell/2018/07/24/federal-report-on-marijuana-legalization-required-under-new-bill/#41b953e73532. Retrieved 15 November 2018.
- "DigiPath, Inc.: A Unique Investment Vehicle in Laboratory Testing" (PDF). DigiPath, Inc. November 2016. pp. 28. http://digipath.com/wp-content/uploads/2016/11/DigiPath-Investor-Presentation-11.3.pdf. Retrieved 03 March 2017.
- "Signal Bay Makes Strategic Acquisition in the $850M Cannabis Testing Market". Signal Bay, Inc. 24 September 2015. https://signalbay.com/company-news/signal-bay-makes-strategic-acquisition-in-the-850m-cannabis-testing-market/. Retrieved 03 March 2017.
- "Marijuana lab testing: An in depth analysis of investing in one of the industry’s most attractive plays". GreeenWave Advisors, LLC. June 2015. https://www.greenwaveadvisors.com/research/marijuana-lab-testing-an-in-depth-analysis-of-investing-in-one-of-the-industrys-most-attractive-plays/. Retrieved 03 March 2017.
- "Cannabis Testing Market to Reach $1.4 Billion by 2021 - Driven by Growing Number of Cannabis Testing Laboratories - Research and Markets". PR Newswire. Research and Markets. 31 March 2017. https://www.prnewswire.com/news-releases/cannabis-testing-market-to-reach-14-billion-by-2021---driven-by-growing-number-of-cannabis-testing-laboratories---research-and-markets-300432416.html. Retrieved 16 November 2018.
- "Cannabis Testing Market Estimated to be Worth US$ 1.5 Billion by 2026". Coherent Market Insights. 09 July 2018. https://www.coherentmarketinsights.com/press-release/cannabis-testing-market-estimated-to-be-worth-us-15-billion-by-2026-64. Retrieved 16 November 2018.
- Nelson, S. (03 August 2016). "Has Lab Testing Turned A Corner?". Cannabis Business Times. GIE Media, Inc. http://www.cannabisbusinesstimes.com/article/has-lab-testing-turned-a-corner/. Retrieved 03 March 2017.
- "New Certification Program Brings Quality Assurance to the Medical Marijuana Industry". Information Forecast, Inc. 2016. http://infocastinc.com/industries/new-certification-program-brings-quality-assurance-to-the-medical-marijuana-industry/. Retrieved 02 February 2017.
- Cannabis Committee, AHPA (02 February 2016). "Recommendations for Regulators – Cannabis Operations" (PDF). American Herbal Products Association. http://www.ahpa.org/Portals/0/pdfs/AHPA_Recommendations_for_Regulators_Cannabis_Operations.pdf.
- Upton, R.; Craker, L.; ElSohly, M. et al., ed. (2014). Cannabis Inflorescence: Cannabis spp.. American Herbal Pharmacopoeia. ISBN 1929425333. http://www.herbal-ahp.org/order_online.htm.
- Project CBD; Marcu, J. (16 March 2016). "Jahan Marcu: Cannabis Lab Testing & Safety Protocols". Project CBD. Project CBD. https://www.projectcbd.org/article/jahan-marcu-cannabis-lab-testing-safety-protocols. Retrieved 03 February 2017.
- Erickson, B.E. (13 November 2017). "Cleaning up cannabis". Chemical & Engineering News. American Chemical Society. https://cen.acs.org/articles/95/i45/Cleaning-cannabis.html. Retrieved 15 November 2018.
- "The Emerald Test". Emerald Scientific, LLC. http://www.theemeraldtest.com/. Retrieved 03 March 2017.
- Lampach, D. (20 November 2013). "Q&A With CEO of Steep Hill Halent: US Cannabis Testing Market Could Hit $40M by 2016". Marijuana Business Daily. Anne Holland Ventures, Inc. https://mjbizdaily.com/qa-with-steep-hill-lab-ceo-david-lampach-cannabis-testing-market-could-hit-40m-in-2-years/. Retrieved 25 January 2017.
- CannabisFN (16 July 2015). "DigiPath (DIGP) Well Positioned To Take Advantage of $850M Cannabis Testing Market". The Marijuana Index. MJIC, Inc. http://marijuanaindex.com/digipath-digp-well-positioned-to-take-advantage-of-850m-cannabis-testing-market/. Retrieved 07 March 2017.
- Schroyer, J. (January 2016). "Industry Snapshot: Testing Labs". Marijuana Business Magazine. Anne Holland Ventures, Inc. https://mjbizmagazine.com/industry-snapshot-testing-labs/. Retrieved 07 March 2017.
- "5 Key Things to Know About the Cannabis Testing Laboratory Business in California". Insights. Kramer Holcomb Sheik LLP. July 2018. https://www.khslaw.com/insights/cannabis-testing-lab-laws-in-california/. Retrieved 16 November 2018.