Tag Archives: microbial

October 21, 2019

3 Essential Components of Microbial Safety Testing

By Heather Ebling

Microbial contamination on cannabis products represents one of the most significant threats to cannabis consumers, particularly immunocompromised patients who are at risk of developing harmful and potentially fatal infections.

As a result, regulatory bodies in the United States and Canada mandate testing cannabis products for certain microbes. The two most popular methods for microbial safety testing in the cannabis industry are culture-based testing and quantitative polymerase chain reaction (qPCR).

When considering patient safety, labs should choose a method that provides an accurate account of what is living on the sample and can specifically target the most harmful microbes, regardless of the matrix.

1. The Method’s Results Must Accurately Reflect the Microbial Population on the Sample

The main objective of any microbial safety test is to give the operator an indication of the microbial population present on the sample.

Figure 1: MA data collected directly from plant material before and after culture on 3M petrifilm and culture-based platforms.

Culture-based methods measure contamination by observing how many organisms grow in a given medium. However, not all microbial organisms grow at the same rate. In some cases, certain organisms will out-compete others and as a result, the population in a post-culture environment is radically different than what was on the original sample.

One study analyzed fifteen medicinal cannabis samples using two commercially available culture-based methods. To enumerate and differentiate bacteria and fungi present before and after growth on culture-based media, all samples were further subjected to next-generation sequencing (NGS) and metagenomic analyses (MA). Figure 1 illustrates MA data collected directly from plant material before and after culture on 3M petrifilm and culture-based platforms.

The results demonstrate substantial shifts in bacterial and fungal growth after culturing on the 3M petrifilm and culture-based platforms. Thus, the final composition of microbes after culturing is markedly different from the starting sample. Most concerning is the frequent identification of bacterial species in systems designed for the exclusive quantification of yeast and mold, as quantified by elevated total aerobic count (TAC) Cq values after culture in the total yeast and mold (TYM) medium. The presence of bacterial colonies on TYM growth plates or cartridges may falsely increase the rejection rate of cannabis samples for fungal contamination. These observations call into question the specificity claims of these platforms.

The Live Dead Problem

Figure 2: The enzyme is instantaneously inactivated when lysis buffer is added

One of the common objections to using qPCR for microbial safety testing is the fact that the method does not distinguish between live and dead DNA. PCR primers and probes will amplify any DNA in the sample that matches the target sequence, regardless of viability. Critics claim that this can lead to false positives because DNA from non-viable organisms can inflate results. This is often called the Live-Dead problem. However, scientists have developed multiple solutions to this problem. Most recently, Medicinal Genomics developed the Grim Reefer Free DNA Removal Kit, which eliminates free DNA contained in a sample by simply adding an enzyme and buffer and incubating for 10 minutes. The enzyme is instantaneously inactivated when lysis buffer is added, which prevents the Grim Reefer Enzyme from eliminating DNA when the viable cells are lysed (see Figure 2).

2. Method Must Be Able to Detect Specific Harmful Species

Toxic Aspergillus spp., which is responsible for at least one confirmed death of a cannabis patient, grows poorly in culture mediums and is severely underreported by current culture-based platforms. And even when Aspergillus does grow in culture, there is a certain non-pathogenic Aspergillus species that look remarkably similar to their pathogenic cousins, making it difficult to speciate using visual identification alone.

Conversely, qPCR assays, such as the PathoSEEK, are designed to target DNA sequences that are unique to pathogenic Aspergillus species, and they can be run using standard qPCR instruments such as the Agilent AriaMx. The primers are so specific that a single DNA base difference in the sequence can determine whether binding occurs. This specificity reduces the frequency of false positives in pathogen detection, a frequent problem with culture-based cannabis testing methods.

Additionally, Medicinal Genomics has developed a multiplex assay that can detect the four pathogenic species of Aspergillus (A. flavus, A. fumigatus, A. niger, and A. terreus) in a single reaction.

3. The Method Must Work on Multiple Matrices

Figure 4: The team also placed TSB without any E. coli onto a petrifilm to serve as a control.

Marijuana infused products (MIPs) are a very diverse class of matrices that behave very differently than cannabis flowers. Gummy bears, chocolates, oils and tinctures all present different challenges to culture-based techniques as the sugars and carbohydrates can radically alter the carbon sources available for growth. To assess the impact of MIPs on colony-forming units per gram of sample (CFU/g) enumeration, The Medicinal Genomics team spiked a known amount of live E. coli into three different environments: tryptic soy broth (TSB), hemp oil and hard candy. The team then homogenized the samples, pipetted amounts from each onto 3M™ Petrifilm E. coli / Coliform Count (EC) Plates, and incubated for 96 hours. The team also placed TSB without any E. coli onto a petrifilm to serve as a control. Figures 3 and 4 show the results in 24-hour intervals.

Table 1: DNA was spiked into various MIPs

This implies the MIPs are interfering with the reporter assay on the films or that the MIPs are antiseptic in nature.

Many MIPs use citric acid as a flavoring ingredient which may interfere with 3M reporter chemistry. In contrast, the qPCR signal from the Agilent AriaMx was constant, implying there is microbial contamination present on the films, but the colony formation or reporting is inhibited.

Table 3: SenSATIVAx DNA extraction can successfully lyse the cells of the microbes

Table 2: Different numbers of DNA copies spiked into chocolate

This is not an issue with DNA-based methods, so long as the DNA extraction method has been validated on these matrices. For example, the SenSATIVAx DNA extraction method is efficient in different matrices, DNA was spiked into various MIPs as shown in Table 1, and at different numbers of DNA copies into chocolate (Table 2). The SenSATIVAx DNA extraction kit successfully captures the varying levels of DNA, and the PathoSEEK detection assay can successfully detect that range of DNA. Table 3 demonstrates that SenSATIVAx DNA extraction can successfully lyse the cells of the microbes that may be present on cannabis for a variety of organisms spiked onto cannabis flower samples.

October 17, 2019

The Best Way to Remediate Moldy Cannabis is No Remediation at All

By Ingo Mueller

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Consumers are largely unaware that most commercial cannabis grown today undergoes some form of decontamination to treat the industry’s growing problem of mold, yeast and other microbial pathogens. As more cannabis brands fail regulatory testing for contaminants, businesses are increasingly turning to radiation, ozone gas, hydrogen peroxide or other damaging remediation methods to ensure compliance and avoid product recalls. It has made cannabis cultivation and extraction more challenging and more expensive than ever, not to mention inflaming the industry’s ongoing supply problem.

The problem is only going to get worse as states like Nevada and California are beginning to implement more regulations including even tougher microbial contamination limits. The technological and economic burdens are becoming too much for some cultivators, driving some of them out of business. It’s also putting an even greater strain on them to meet product demand.

It’s critical that the industry establishes new product standards to reassure consumers that the cannabis products they buy are safe. But it is even more critical that the industry look beyond traditional agricultural remediation methods to solve the microbial problems.

Compounding Risks

Mold and other microbial pathogens are found everywhere in the environment, including the air, food and water that people consume. While there is no consensus yet on the health consequences of consuming these contaminants through cannabis, risks are certainly emerging. According to a 2015 study by the Cannabis Safety Instituteⁱ, molds are generally harmless in the environment, but some may present a health threat when inhaled, particularly to immunocompromised individuals. Mycotoxins resulting from molds such as Aspergillus can cause illnesses such as allergic bronchopulmonary aspergillosis. Even when killed with treatment, the dead pathogens could trigger allergies or asthma.

Photo credit: Steep Hill- a petri dish of mold growth from tested cannabis

There is an abundance of pathogens that can affect cannabis cultivation, but the most common types are Botrytis (bud rot, sometimes called gray mold) and Powdery Mildew. They are also among the most devastating blights to cannabis crops. Numerous chemical controls are available to help prevent or stem an outbreak, ranging from fungicides and horticultural oils to bicarbonates and biological controls. While these controls may save an otherwise doomed crop, they introduce their own potential health risks through the overexposure and consumption of chemical residues.

The issue is further compounded by the fact that the states in which cannabis is legal can’t agree on which microbial pathogens to test for, nor how to test. Colorado, for instance, requires only three pathogen tests (for salmonella, E. coli, and mycotoxins from mold), while Massachusetts has exceedingly strict testing regulations for clean products. Massachusetts-based testing lab, ProVerde Laboratories, reports that approximately 30% of the cannabis flowers it tests have some kind of mold or yeast contamination.

If a cannabis product fails required microbial testing and can’t be remedied in a compliant way, the grower will inevitably experience a severe – and potentially crippling – financial hit to a lost crop. Willow Industries, a microbial remediation company, says that cannabis microbial contamination is projected to be a $3 billion problem by 2020ⁱⁱ.

Remediation Falls Short
With the financial stakes so high, the cannabis industry has taken cues from the food industry and adopted a variety of ways to remediate cannabis harvests contaminated with pathogens. Ketch DeGabrielle of Qloris Consulting spent two years studying cannabis microbial remediation methods and summarized their pros and consⁱⁱⁱ.

He found that some common sterilization approaches like autoclaves, steam and dry heat are impractical for cannabis due the decarboxylation and harsh damage they inflict on the product. Some growers spray or immerse cannabis flowers in hydrogen peroxide, but the resulting moisture can actually cause more spores to germinate, while the chemical reduces the terpene content in the flowers.

Powdery mildew starts with white/grey spots seen on the upper leaves surface

The more favored, technologically advanced remediation approaches include ozone or similar gas treatment, which is relatively inexpensive and treats the entire plant. However, it’s difficult to gas products on a large scale, and gas results in terpene loss. Microwaves can kill pathogens effectively through cellular rupture, but can burn the product. Ionizing radiation kills microbial life by destroying their DNA, but the process can create carcinogenic chemical compounds and harmful free radicals. Radio frequency (which DeGabrielle considers the best method) effectively kills yeast and mold by oscillating the water in them, but it can result in moisture and terpene loss.

The bottom line: no remediation method is perfect. Prevention of microbial contamination is a better approach. But all three conventional approaches to cannabis cultivation – outdoors, greenhouses and indoor grow operations – make it extremely difficult to control contamination. Mold spores can easily gain a foothold both indoors and out through air, water, food and human contact, quickly spreading into an epidemic.

The industry needs to establish new quality standards for product purity and employ new growing practices to meet them. Advanced technologies can help create near perfect growing ecosystems and microclimates for growing cannabis free of mold contamination. Internet of Things sensors combined with AI-driven robotics and automation can dramatically reduce human intervention in the growing process, along with human-induced contamination. Natural sunlight supplemented with new lighting technologies that provide near full-light and UV spectrum can stimulate robust growth more resistant to disease. Computational fluid dynamic models can help growers achieve optimal temperature, humidity, velocity, filtration and sanitation of air flow. And tissue culture micropropagation of plant stock can eliminate virus and pathogen threats, to name just a few of the latest innovations.

Growing legal cannabis today is a risky business that can cost growers millions of dollars if pathogens contaminate a crop. Remediation methods to remove microbial contamination may work to varying degrees, but they introduce another set of problems that can impact consumer health and comprise product quality.

References

i. Holmes M, Vyas JM, Steinbach W, McPartland J. 2015. Microbiological Safety Testing of Cannabis. Cannabis Safety Institute. http://cannabissafetyinstitute.org/wp-content/uploads/2015/06/Microbiological-Safety-Testing-of-Cannabis.pdf

ii. Jill Ellsworth, June 2019, Eliminating Microbials in Marijuana, Willow Industries, https://willowindustries.com/eliminating-microbials-in-marijuana/#

iii. Ketch DeGabrielle, April 2018, Largest U.S. Cannabis Farm Shares Two Years of Mold Remediation Research, Analytical Cannabis, https://www.analyticalcannabis.com/articles/largest-us-cannabis-farm-shares-two-years-of-mold-remediation-research-299842

October 15, 2019

Soapbox

Searching for the Good Stuff

By Cindy Rice

1 Comment

Someone approached me the other day, wanting to know what was the real story about hemp and CBD.

He said he had “a guy” who gave him a CBD salve as part of a study, supposedly “the good stuff,” to help his knee. He couldn’t understand why he was the only one out of 20 people in the group that felt no relief. He happened to have this CBD salve with him, along with a second brand that he hadn’t yet tried. The “good stuff” had slick, colorful packaging, a beautiful logo and powerful marketing messages about the phytocannabinoids and essential oils in the jar. The other CBD product was in a dull grey tin, an ugly duckling, and not nearly so impressive on the outside- I’ll call it “Homer’s Brew.” My friend dismissed Homer’s Brew outright, as not even worth trying. I told him that not all CBD products are created equal, that you can’t always believe the claims on the package, including the cannabinoid potency displayed on the label.

The structure of cannabidiol (CBD), one of 400 active compounds found in cannabis.

I told him to search for the Certificate of Analysis (COA) for each of the two products, specifically, lab test results validating the CBD dosage per serving, and also the breakdown of pesticides, heavy metals and microbials. He had to do a little digging and emailing, as it wasn’t readily available for either company, but the next day, results were in. The “good stuff” with the slick packaging and bold claims had mere trace amounts of CBD, with some hemp and essential oils- no tests for pesticides or contaminants of any kind. Hmmm, no wonder he was disappointed. Homer’s Brew’s COA came in with flying colors – a reputable lab had confirmed safe levels of pesticides, pathogens and heavy metals, and the CBD level was substantial, with a detailed cannabinoid breakdown in the lab report.

In spite of the varying legality of hemp-derived CBD products from one state to the next, consumers are gobbling up costly CBD salves, tinctures and edibles in markets, gyms and online. Like moths to a flame, they are pulled in by the CBD name and lofty promises, not always understanding what they are getting for their money. They trust that these products are safe, licensed, inspected and regulated by some agency, otherwise, “they wouldn’t be on the shelves, would they?”

In spite of the 2018 Farm Bill, FDA still has not recognized the legality of products containing hemp-derived CBD, but some states have gone ahead and given them a green light anyway- check with your own jurisdiction to be sure. In the meantime, hemp-derived CBD products are slipping through the regulatory cracks, depending on the state. It is confusing, for sure, and buyer beware.

Separate yourself from the pack of snake-oil salesmen. Test your products for safety and accurate cannabinoid potency, and make a Certificate of Analysis readily available to your customers. Boldly portray your transparency and belief in the quality of your products through this COA.

Providing this information to consumers is the best path to success- safe, satisfied customers who will refer to their friends and family, and most likely come back for more of your “good stuff.”

October 9, 2019

From The Lab

Spotlight on Encore Labs: Servicing the Cannabis Market in California

By Kristen Hogerheide

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Encore Labs is a full-service cannabis testing lab in Pasadena, California, providing all testing needs required by California’s Bureau of Cannabis Control (BCC). The BCC requires that cannabis products being sold in licensed dispensaries be tested for cannabinoid potency, heavy metals, microbial impurities, moisture content and water activity, mycotoxins, residual pesticides, residual solvents and processing chemicals, foreign materials and terpenes. It is Encore Labs’ goal to guarantee the quality and potency of all cannabis products while ensuring regulatory guidelines are met in the state of California.

Encore Labs provides quick turnaround times on a consistent basis. They take pride in offering excellent customer service without diminishing the quality of the work that they do. Their team of laboratory analysts/technicians are passionate about the industry and will never compromise their integrity just to make an extra buck.

Co-Founder, Spencer Wong, mentions their personal connection with clients. “Our customers don’t just see us as their testing laboratory, they see Encore Labs as their laboratory partner,” says Wong. “Besides performing analytical testing, we have worked with many customers to help formulate new products and do root cause analysis to pinpoint inefficiencies in their manufacturing operations and cultivation farms.”

ISO/IEC 17025 Accreditation has been extremely valuable to Encore Labs, especially regarding the new cannabis testing industry. “Our experience with Perry Johnson Laboratory Accreditation, Inc. has been great and has allowed for a very smooth and straightforward initial accreditation process. Their staff has been knowledgeable and responsive every step of the way,” says Wong.

Accreditation establishes that steps are being taken regarding quality and that laboratories are meeting and exceeding the highest testing standards. It also provides further assurance and confidence in data results as well as validated methods, staff training procedures, equipment calibration and successful participation in proficiency testing/interlaboratory comparisons.

Starting out with 1500 square feet of laboratory space, within the last year Encore Labs has doubled its work area. In order to meet the growing demand of the cannabis testing industry, they have added plans to once again double in size by the end of 2019, as well as open a second laboratory by the end of 2020.

September 27, 2019

Analytical Instruments You Need to Start a Cannabis Testing Laboratory

By Bob Clifford

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The cannabis industry is growing exponentially, and the use of cannabis for medical purposes is being adopted across the nation. With this boom in cannabis consumers, there has been an increasing need for knowledge about the product.

The role of testing labs has become crucial to the process, which makes owning and operating a lab more lucrative. Scientists testing for potency, heavy metals, pesticides, residual solvents, moisture, terpene profile, microbial and fungal growth, and mycotoxins/aflatoxins are able to make meaningful contributions to the medical industry by making sure products are safe, while simultaneously generating profits and a return on investment.

Here are the key testing instruments you need to conduct these critical analyses. Note that cannabis analytical testing requirements may vary by state, so be sure to check the regulations applicable to the location of your laboratory.

Potency Testing

High-performance liquid chromatograph (HPLC) designed for quantitative determination of cannabinoid content.

The most important component of cannabis testing is the analysis of cannabinoid profiles, also known as potency. Cannabis plants naturally produce cannabinoids that determine the overall effect and strength of the cultivar, which is also referred to as the strain. There are many different cannabinoids that all have distinct medicinal effects. However, most states only require testing and reporting for the dry weight percentages of delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). It should be noted that delta-9-tetrahydrocannabinolic acid (Δ9-THCA) can be converted to THC through oxidation with heat or light.

For potency testing, traditional high-performance liquid chromatography (HPLC) is recommended and has become the gold standard for analyzing cannabinoid profiles. Look for a turnkey HPLC analyzer that delivers a comprehensive package that integrates instrument hardware, software, consumables and proven HPLC methods.

Heavy Metal Testing

ICP-MS instrument for detecting heavy metals in cannabis.

Different types of metals can be found in soils and fertilizers, and as cannabis plants grow, they tend to draw in these metals from the soil. Heavy metals are a group of metals considered to be toxic, and the most common include lead, cadmium, arsenic and mercury. Most labs are required to test and confirm that samples are under the allowable toxic concentration limits for these four hazardous metals.

Heavy metal testing is performed by inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS uses the different masses of each element to determine which elements are present within a sample and at what concentrations. Make sure to include accompanying software that provides assistant functions to simplify analysis by developing analytical methods and automatically diagnosing spectral interference. This will provide easy operation and analytical results with exceptionally high reliability.

To reduce running costs, look for a supporting hardware system that reduces the consumption of argon gas and electricity. For example, use a plasma ignition sequence that is optimized for lower-purity argon gas (i.e., 99.9% argon as opposed to more expensive 99.9999%).

Pesticide Testing

The detection of pesticides in cannabis can be a challenge. There are many pesticides that are used in commercial cannabis grow operations to kill the pests that thrive on the plants and in greenhouses. These chemicals are toxic to humans, so confirming their absence from cannabis products is crucial. The number of pesticides that must be tested for varies from state to state, with Colorado requiring only 13 pesticides, whereas Oregon and California require 59 and 66 respectively. Canada has taken it a step further and must test for 96 pesticides, while AOAC International is developing methods for testing for 104 pesticides. The list of pesticides will continue to evolve as the industry evolves.

Testing for pesticides is one of the more problematic analyses, possibly resulting in the need for two different instruments depending on the state’s requirements. For a majority of pesticides, liquid chromatography mass spectrometry (LCMS) is acceptable and operates much like HPLC but utilizes a different detector and sample preparation.

With excellent sensitivity and ultra-low detection limits, LC-MS/MS is an ideal technique for the analysis of pesticides.

Pesticides that do not ionize well in an LCMS source require the use of a gas chromatography mass spectrometry (GCMS) instrument. The principles of HPLC still apply – you inject a sample, separate it on a column and detect with a detector. However, in this case, a gas (typically helium) is used to carry the sample.

Look for a LC-MS/MS system or HPLC system with a triple quadrupole mass spectrometer that provides ultra-low detection limits, high sensitivity and efficient throughput. Advanced systems can analyze more than 200 pesticides in 12 minutes.

For GCMS analysis, consider an instrument that utilizes a triple quadrupole mass spectrometer to help maximize the capabilities of your laboratory. Select an instrument that is designed with enhanced functionality, analysis software, databases and a sample introduction system. Also include a headspace autosampler, which can also be used for terpene profiles and residual solvent testing.

Residual Solvent Testing

Residual solvents are chemicals left over from the process of extracting cannabinoids and terpenes from the cannabis plant. Common solvents for such extractions include ethanol, butane, propane and hexane. These solvents are evaporated to prepare high-concentration oils and waxes. However, it is sometimes necessary to use large quantities of solvent in order to increase extraction efficiency and to achieve higher levels of purity. Since these solvents are not safe for human consumption, most states require labs to verify that all traces of the substances have been removed.

Testing for residual solvents requires gas chromatography (GC). For this process, a small amount of extract is put into a vial and heated to mimic the natural evaporation process. The amount of solvent that is evaporated from the sample and into the air is referred to as the “headspace.” The headspace is then extracted with a syringe and placed in the injection port of the GC. This technique is called full-evaporated technique (FET) and utilizes the headspace autosampler for the GC.

Look for a GCMS instrument with a headspace autosampler, which can also be used for pesticide and terpene analysis.

Terpene Profile Testing

Terpenes are produced in the trichomes of the cannabis leaves, where THC is created, and are common constituents of the plant’s distinctive flavor and aroma. Terpenes also act as essential medicinal hydrocarbon building blocks, influencing the overall homeopathic and therapeutic effect of the product. The characterization of terpenes and their synergistic effect with cannabinoids are key for identifying the correct cannabis treatment plan for patients with pain, anxiety, epilepsy, depression, cancer and other illnesses. This test is not required by most states, but it is recommended.

The instrumentation that is used for analyzing terpene profiles is a GCMS with headspace autosampler with an appropriate spectral library. Since residual solvent testing is an analysis required by most states, all of the instrumentation required for terpene profiling will already be in your lab.

As with residual solvent testing, look for a GCMS instrument with a headspace autosampler (see above).

Microbe, Fungus and Mycotoxin Testing

Most states mandate that cannabis testing labs analyze samples for any fungal or microbial growth resulting from production or handling, as well as for mycotoxins, which are toxins produced by fungi. With the potential to become lethal, continuous exposure to mycotoxins can lead to a buildup of progressively worse allergic reactions.

LCMS should be used to qualify and identify strains of mycotoxins. However, determining the amount of microorganisms present is another challenge. That testing can be done using enzyme linked immunosorbent assay (ELISA), quantitative polymerase chain reaction (qPCR) or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with each having their advantages and disadvantages.

For mycotoxin analysis, select a high-sensitivity LC-MS/MS instrument. In addition to standard LC, using an MS/MS selective detector enables labs to obtain limits of detection up to 1000 times greater than conventional LC-UV instruments.

For qPCR and its associated needs, look for a real-time PCR amplification system that combines thermal cyclers with optical reaction modules for singleplex and multiplex detection of fluorophores. These real-time PCR detection systems range from economical two-target detection to sophisticated five-target or more detection systems. The real-time detection platform should offer reliable gradient-enabled thermal cyclers for rapid assay optimization. Accompanying software built to work with the system simplifies plate setup, data collection, data analysis and data visualization of real-time PCR results.

Moisture Content and Water Activity Testing

Moisture content testing is required in some states. Moisture can be extremely detrimental to the quality of stored cannabis products. Dried cannabis typically has a moisture content of 5% to 12%. A moisture content above 12% in dried cannabis is prone to fungal growth (mold). As medical users may be immune deficient and vulnerable to the effects of mold, constant monitoring of moisture is needed. Below a 5% moisture content, the cannabis will turn to a dust-like texture.

The best way to analyze the moisture content of any product is using the thermogravimetric method with a moisture balance instrument. This process involves placing the sample of cannabis into the sample chamber and taking an initial reading. Then the moisture balance instrument heats up until all the moisture has been evaporated out of the sample. A final reading is then taken to determine the percent weight of moisture that was contained in the original sample.

A moisture balance can provide accurate determination of moisture content in cannabis.

Look for a moisture balance that offers intuitive operation and quick, accurate determination of moisture content. The pan should be spacious enough to allow large samples to be spread thinly. The halogen heater and reflector plate should combine to enable precise, uniform heating. Advanced features can include preset, modifiable measurement modes like automated ending, timed ending, rapid drying, slow drying and step drying.

Another method for preventing mold is monitoring water activity (a_W). Very simply, moisture content is the total amount of water available, while water activity is the “free water” that could produce mold. Water activityranges from 0 to 1. Pure water would have an a_W of 1.0. ASTM methods D8196-18 and D8297-18 are methods for monitoring water activity in dry cannabis flower. The a_W range recommended for storage is 0.55 to 0.65. Some states recommend moisture content to be monitored, other states monitor water activity, and some states such as California recommend monitoring both.

Final Thoughts

As you can see, cannabis growers benefit tremendously from cannabis testing. Whether meeting state requirements or certifying a product, laboratory testing reduces growers’ risk and ensures delivery of a quality product. As medicinal and recreational cannabis markets continue to grow, analytical testing will ensure that consumers are receiving accurately

labeled products that are free from contamination. That’s why it is important to invest in the future of your cannabis testing lab by selecting the right analytical equipment at the start of your venture.

August 28, 2019

Denver Plans Crackdown on Contaminants

By Aaron G. Biros

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Earlier this month, Colorado cannabis producer Herbal Wellness LLC recalled dozens of batches of cannabis due to positive yeast and mold tests. The Colorado Department of Public Health and Environment (CDPHE) issued a health and safety advisory following the news of microbial contamination.

The Colorado Department of Revenue then identified batches of both medical and recreational cannabis produced by Herbal Wellness that were not even tested for microbial contaminants, which is a requirement for licensed producers in the state. Just a few days later, the Denver Department of Public Health & Environment (DDPHE) issued a bulletin announcing their plans to conduct random tests at dozens of dispensaries.

“In the coming weeks, the Denver Department of Public Health & Environment (DDPHE) will be conducting an assessment in approximately 25 retail marijuana stores to evaluate contaminants in products on store shelves,” reads the bulletin. “DDPHE has worked with epidemiological partners at Denver Public Heath to create the assessment methodology. Participating stores will be randomly identified for inclusion in the assessment.”

“Current METRC inventory lists for each store will be used to randomly identify samples of flower, trim/shake, and pre-rolls. Each sample will be tested for pesticides and total yeast and mold by a state- and ISO-certified marijuana testing facility. Results of their respective testing will be shared with each facility and will also be shared broadly within a write-up of results.”

March 6, 2019

Product Release: PathogenDx Announces New Products, Branding

By Aaron G. Biros

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According to a press release published earlier this week, PathogenDx, Inc., is expanding their product portfolio and doing some rebranding. The DNA-based pathogen detection testing provider, headquartered in Scottsdale, Arizona, produces microarray testing platforms for the cannabis, agriculture and food and beverage industries. Their rapid testing technology can reportedly identify and detect 50+ pathogens all in a single test, including common pathogens such as E. Coli, Salmonella and Aspergillus.

Here is a look at their new product suite, taken from the press release:

DetectX – Tests for the presence of pathogenic microbial organisms down to a single organism, at less than 0.1 CFU/gram for state regulated compliance. Test 96 or more samples a day for multiple state mandated microbial pathogens, with product safety certainty delivered in 6 hours, far more rapid than current industry standards of 72 hours or more.
QuantX – The world’s first quantification microarray test for Cannabis. This test measures the microbial load in a sample, while also providing discrimination of the organism content relative to testing standards. Regulatory agencies will now have the opportunity to improve microbial testing standards to ensure safety.
EnviroX – With a single swab, one can identify 50+ species and classes of microbes, with quick-turn results, by simply swabbing a grower/cultivation facility surfaces and vents. Submit, identify, and remediate. It’s that simple to mitigate risk to high-value crops.
PhytoX – Coming in Summer of 2019, PathogenDx will introduce the ultra-rapid, easy plant pathogen test to detect powdery mildew, gray mold, mites and other microbial bugs that can become destructive threats to one’s crop. Acquire results in 6 hours to intercept and redress infestation that can destroy one’s yield.

According to CEO and Co-Founder Milan Patel, they want their technology to set the standard for product safety testing. “We’re making the accurate testing of cannabis, food and agriculture faster, more definitive and less expensive with trackable results benefitting growers, producers, regulators and consumers worldwide,” says Patel. “Our new brand is inspired by our unique microplex array and is bright, fresh, memorable and expansive, enabling us to move from cannabis only to much larger global consumable markets where we can continue to offer new products and applications for the technology.”

This announcement comes as the company is positioning itself to expand far beyond just the cannabis testing arena, diving into the food and beverage and agriculture industries with a much stronger presence. As recently as late February, the company announced purchases of new real estate, expanding their production capacity, as well as announcing a few key hires, expanding their leadership team.

June 6, 2018

EVIO Labs Expands Ahead of California Testing Deadline

By Aaron G. Biros

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In a few short weeks, the regulations in California’s cannabis market will expand to include more laboratory testing. The previous exemption for selling untested product will be eliminated come July 1^st, meaning that every product on dispensary shelves will have to be tested for a number of contaminants.

EVIO labs photo — Pesticide testing, expanded residual solvent testing and foreign materials testing will be added come July 1st.

According to William Waldrop, chief executive officer and co-founder of EVIO Labs, the state is currently finalizing a revision to the existing emergency rules, which is designed to target the potential supply bottleneck situation. “To help alleviate the bottleneck, the state is eliminating the field duplicate test on every batch of cannabis or cannabis products,” says Waldrop. “This will give the labs additional bandwidth to process more batches for testing.” So one test per batch is the rule now and batch sizes will remain the same. This, of course, is contingent on the state finalizing that revision to the emergency regulations.

William Waldrop, chief executive officer and co-founder of EVIO Labs

In addition to that change, the state will expand the types of testing requirements come July 1^st. New mandatory pesticide testing, expanded residual solvent testing and foreign materials testing are added in addition to the other tests already required.

With July 1^stquickly approaching, many in California fear the rules could lead to a major market disruption, such as the previously mentioned bottleneck. Waldrop sees the elimination of duplicate testing as a preventative measure by the state. “It is a good move for the industry because it allows labs to test more batches, hopefully reducing the bottleneck come July,” says Waldrop. Still though, with only 26 licensed laboratories in the state as of March, testing facilities will have to meet higher demand, performing more tests and working with more clients.

EVIO Labs is preparing for this in a number of ways. They already have a lab in Berkeley and are working to expand their capacity for more analyses. In addition to their lab in Berkeley, the company is working to get three more locations operational as quickly as possible. “Right now, EVIO Labs is expanding through the identification of new market locations,” says Waldrop. “We have announced the acquisition of a facility in Humboldt and we are outfitting it for state-mandated testing. We have secured a location in LA, and licensing for LA just began as of June 1^stso we are going through the local licensing process at this time. We are still moving through the licensing process for our facility in Costa Mesa as well.”

“In the meantime, we have expanded capacity of personnel in our Berkeley facility to support our client base until these other locations come online,” says Waldrop. “We are refining our business, bringing on additional equipment and more resources.” While the rules haven’t been implemented yet, Waldrop says he’s seen an uptick in business with licensed operators requesting more testing for the new July 1^ststandards.

While some might feel a bit panicky about how the new standards could disrupt the market, Waldrop says his clients are looking forward to it. “Our clients are very happy with the proposed new rules, because it reduces the cost of testing per batch, which will inherently reduce wholesale costs, making cannabis more affordable for patients and recreational users.”

March 28, 2018

Environmental Controls: The Basics

By Vince Sebald

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The outside environment can vary widely depending on where your facility is located. However, the internal environment around any activity can have an effect on that activity and any personnel performing the activity, whether that’s storage, manufacturing, testing, office work, etc. These effects can, in turn, affect the product of such activities. Environmental control strategies aim to ensure that the environment supports efforts to keep product quality high in a manner that is economical and sensible, regardless of the outside weather conditions.

For this article, let us define the “environment” as characteristics related to the room air in which an activity is performed, setting aside construction and procedural conditions that may also affect the activity. Also, let us leave the issue of managing toxins or potent compounds for another time (as well as lighting, noise, vibration, air flow, differential pressures, etc). The intent here is to focus on the basics: temperature, humidity and a little bit on particulate counts.

Temperature and humidity are key because a non-suitable environment can result in the following problems:

Operator discomfort
Increased operator error
Difficulty in managing products (e.g. powders, capsules, etc)
Particulate generation
Degradation of raw materials
Product contamination
Product degradation
Microbial and mold growth
Excessive static

USP <659> “Packaging and Storage Requirements” identifies room temperature as 20-25°C (68-77 °F) and is often used as a guideline for operations. If gowning is required, the temperature may be reduced to improve operator comfort. This is a good guide for human working areas. For areas that require other specific temperatures (e.g. refrigerated storage for raw materials), the temperature of the area should be set to those requirements.

Humidity can affect activities at the high end by allowing mold growth and at the low end by increasing static. Some products (or packaging materials) are hydroscopic, and will take on water from a humid environment. Working with particular products (e.g. powders) can also drive the requirement for better humidity control, since some powders become difficult to manage in either high or low humidity environments. For human operations without other constraints, a typical range for desirable humidity is in the range of 20 to 70% RH in manufacturing areas, allowing for occasional excursions above. As in the case of temperature, other requirements may dictate a different range.

In a typical work environment, it is often sufficient to control the temperature, while allowing the relative humidity to vary. If the humidity does not exceed the limits for the activity, then this approach is preferred, because controlling humidity adds a level of complexity (and cost) to the air handling. If humidity control is required, it can be managed by adding moisture via various humidification systems, or cooling/reheating air to remove moisture. When very low humidity is required, special equipment such as a desiccant system may be required. It should be noted that although you can save money by not implementing humidity control at the beginning, retrofitting your system for humidity control at a later time can be expensive and require a shutdown of the facility.

Good engineering practice can help prevent issues that may be caused by activities performed in inappropriately controlled environments. The following steps can help manage the process:

Plan your operations throughout your facility, taking into account the requirements for the temperature and humidity in each area and know what activities are most sensitive to the environment. Plans can change, so plan for contingencies whenever possible.
Write down your requirements in a User Requirement Specification (URS) to a level of detail that is sufficient for you to test against once the system is built. This should include specific temperature and RH ranges. You may have additional requirements. Don’t forget to include requirements for instrumentation that will allow you to monitor the temperature and RH of critical areas. This instrumentation should be calibrated.
Solicit and select proposals for work based on the URS that you have generated. The contractor will understand the weather in the area and can ensure that the system can meet your requirements. A good contractor can also further assist with other topics that are not within the scope of this article (particulates, differential pressures, managing heating or humidity generating equipment effects, etc).
Once work is completed, verify correct operation using the calibrated instrumentation provided, and make sure you add periodic calibration of critical equipment, as well as maintenance of your mechanical system(s), to your calibration and maintenance schedules, to keep everything running smoothly.

The main point is if you plan your facility and know your requirements, then you can avoid significant problems down the road as your company grows and activity in various areas increases. Chances are that a typical facility may not meet your particular requirements, and finding that out after you are operational can take away from your vacation time and peace of mind. Consider the environment, its good business!

February 20, 2018

An Insider’s View: How Labs Conduct Cannabis Mold Testing

By Swetha Kaul, PhD

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As both recreational and medical cannabis legalization continues to progress across the country, each state is tasked with developing regulatory requirements to ensure that customers and patients receive clean cannabis for consumption. This requires cannabis to undergo laboratory testing that analyzes the presence of microbial impurities including yeast and mold.

Some states, such as Colorado, Nevada, Maine, Illinois and Massachusetts use total yeast and mold count testing (TYMC) and set a maximum yeast and mold count threshold that cultivators must fall below. Other states, such as California, require the detection of species-specific strains of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which requires analyzing the DNA of a cannabis sample through polymerase chain reaction testing, also known as PCR.

Differences in state regulations can lead to different microbiological techniques implemented for testing.Before diving in further, it is important to understand the scientific approach. Laboratory testing requirements for cannabis can be separated into two categories: analytical chemistry methods and microbiological methods.

Analytical chemistry is the science of qualitatively and quantitatively determining the chemical components of a substance, and usually consists of some kind of separation followed by detection. Analytical methods are used to uncover the potency of cannabis, analyze the terpene profile and to detect the presence of pesticides, chemical residues, residuals solvents, heavy metals and mycotoxins. Analytical testing methods are performed first before proceeding to microbiological methods.

Petri dish containing the fungus Aspergillus flavus. It produces carcinogenic aflatoxins, which can contaminate certain foods and cause aspergillosis, an invasive fungal disease.
Photo courtesy of USDA ARS & Peggy Greb.

Microbiological methods dive deeper into cannabis at a cellular level to uncover microbial impurities such as yeast, mold and bacteria. The techniques utilized in microbiological methods are very different from traditional analytical chemistry methods in both the way they are performed and target of the analysis. Differences in state regulations can lead to different microbiological techniques implemented for testing. There are a variety of cell and molecular biology techniques that can be used for detecting microbial impurities, but most can be separated into two categories:

Methods to determine total microbial cell numbers, which typically utilizes cell culture, which involves growing cells in favorable conditions and plating, spreading the sample evenly in a container like a petri dish. The total yeast and mold count (TYMC) test follows this method.
Molecular methods intended to detect specific species of mold, such as harmful aspergillus mold strains, which typically involves testing for the presence of unique DNA sequences such as Polymerase Chain Reaction (PCR).

Among states that have legalized some form of cannabis use and put forth regulations, there appears to be a broad consensus that the laboratories should test for potency (cannabinoids concentration), pesticides (or chemical residues) and residual solvents at a minimum. On the other hand, microbial testing requirements, particularly for mold, appear to vary greatly from state to state. Oregon requires random testing for mold and mildew without any details on test type. In Colorado, Nevada, Maine, Illinois and Massachusetts, regulations explicitly state the use of TYMC for the detection of mold. In California, the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which are difficult to differentiate on a plate and would require a DNA-based approach. Since there are differences in costs associated and data produced by these methods, this issue will impact product costs for cultivators, which will affect cannabis prices for consumers.