2 November 2017

Surface Run-Off Contamination ​

Another water contamination source is surface run-off. Severely compacted and hydric, meaning waterlogged, soils are more prone to surface run-off because the potential for infiltration has been drastically reduced. As heavy rains fall, the rate of infiltration is slower than the rate of rainfall and the result is surface run-off. Once a soil has reached its water-holding capacity, infiltration ceases and all falling water reverts to surface run-off. Instead of dissolved chemicals moving through the soil and into the groundwater, soluble chemicals are moved away over the surface and may be carried directly into natural water sources like rivers and lakes.

New research on surface run-off by Jan Vymazal and Tereza Březinová (2015) shows promise in how cultivators might prevent and limit water run-off while using plants to clean contaminated surface run-off water.

Attempts to prevent run-off from farms using vegetated ditches and fabricated wetlands alongside fields have been more popularized due to the increasing knowledge and awareness of the hazards of contamination. Wetland vegetation had been used sporadically in the past to remove excess fertilizers, but has only become more accepted in the last ten years or so for removing pesticides. Because surface run-off almost immediately enters waterways, the risk of pesticide contamination is much higher than the slower, albeit irreversible, contamination through a soil profile once it meets the groundwater.

Methods involving permanently installed vegetation have been successful in removing pesticides from water. Ditches surrounding fields filled with riparian vegetation act as a buffer between the field and natural water sources. These constructed wetlands act as water treatment systems, engineered and built to engage the natural processes of wetland vegetation, soils, and their associated microbial populations. These fabricated wetlands assist in treating contaminated surface run-off through physical, chemical and biological mechanisms. Results of this research indicate that pesticide removal is variable for singular pesticides, but that they can be categorized according to their chemical composition. Although some types of pesticides are better removed than others, future research opportunities comparing the various constructed wetlands in a single location offer promise for determining the most effective systems for treating different pesticide types.

Preventing Water Contamination and Secondary Contamination of Cannabis

Greater awareness of the types and characteristics of chemicals, soil and water sources used when cultivating Cannabis, and any other crop for that matter, will help prevent further contamination of the waterways we all share. Water can be tested for pesticides to ensure against secondary contamination of Cannabis through pesticide tainted water.

Understanding varying pesticide solubility and degradation rates will help growers better understand how to apply such chemicals without adding the unnecessary stress of contamination to local water sources. Integrating manufactured wetlands and other bioremediation tools in the cultivation area can also help enhance the quality of our water. Utilizing integrated pest management plans can help reduce the need for chemical interventions during cultivation, thus limiting future water contamination.

Limiting or eradicating the usage of pesticides in agriculture may have adverse results on crop yield, but on the other end of the spectrum, increasing pesticide use to further increase yield may present disastrous consequences for our environment. The balance lies in arming oneself with the knowledge about these compounds and how they affect other systems to allow for the use of such products in a responsible manner.

Soil and water are not endless resources, and ancient civilizations that have destroyed the soil and water sources in which they relied upon should serve as a reminder that no amount of technology can resolve the issue of using a resource quicker than it can be replenished or purified

Kaylynne Marquez
Laboratory Manager and Quality Officer
EVIO Labs Eugene


Brady NC, Weil RR (2010) “Soil and the Hydrologic Cycle.” Elements of the Nature and Properties of Soils. Third ed. Upper Saddle River, NJ: Pearson Prentice Hall. Print.

Grube A, Donaldson D, Kiely T, Wu L (2011) Pesticides industry sales and usage: 2006 and 2007 market estimates. EPA 733-R-11-001. U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention.

Hwang JI, Lee SE, Kim JE (2015) Plant uptake and distribution of endosulfan and its sulfate metabolite persisted in soil. PLoS ONE 10(11): e0141728. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141728#pone.0141728.ref010

Toccalino PL, Giolliom RJ, Lindsey BD, Rupert MG (2014) Pesticides in groundwater of the United States: decadal-scale changes, 1993-2011. Groundwater 52(1): 112-125 http://dx.doi.org.libproxy.uoregon.edu/10.1111/gwat.12176

Vymazal J, Březinová T (2015) The use of constructed wetlands for removal of pesticides from agricultural runoff and drainage: A review. Environment International 75: 11-20 www.sciencedirect.com/science/article/pii/S0160412014003201


Ms. Marquez began working as a Cannabis testing laboratory technician for Oregon Analytical Services in 2014. In 2016 she became responsible for the management of back-office operations of the laboratory, including quality assurance, compliance, and procurement. She also provides microbiological testing services for the lab.

Prior to joining OAS and the EVIO Labs group, she worked with Dr. Alan Shanks at The Shanks Lab at the Oregon Institute of Marine Biology on a variety of research projects. She also worked as a Naturalist where she provided educational tours elucidating the ecology of the Pacific Northwest through Whale Research EcoExursions. She was selected to work as intern in the highly competitive Centers for Ocean Sciences Education Experience (COSEE) where she stayed on as a lab technician. Her work included deployment of oceanographic instruments and microscopy work at sea.

Ms. Marquez has prior experience working for a financial investment firm where she worked as assistant to the President performing documentation and staffing tasks. A member of the Phi Theta Kappa Honor Society, Kaylynne Marquez is currently completing her degree in Biology at the University of Oregon.

2 November 2017

Are You Contaminating Your Cannabis With Tainted Water?

Understanding Water Source Contamination and Secondary Contamination of Crops in Cannabis Cultivation
by Kaylynne Marquez, EVIO Labs Eugene

A Look at the Problem

“In 2007 alone, approximately 390 million kilograms of pesticides, including herbicides, insecticides and fungicides, were used in the United States…”

Pesticides play a large role in the modern day agricultural industry, and the need for larger yields, free of unwanted pest organisms, has led to large-scale applications of such products. What happens to those products when heavy rains saturate the soil and run-off into local waterways, or enter the groundwater supply by means of soil infiltration? Chemical contamination from things like pesticides can cause a number of threats to non-target systems. The use of contaminated water in cultivation can cause secondary contamination of crops and pass on to consumers.

The legalization of Cannabis in states like Oregon, Washington and Colorado have led to large scale grow operations, both indoor and outdoor. And just as with any other form of agriculture, the demand for higher yields is ever-growing. Inappropriate management and irrigation technology, in all forms of agriculture, can lead to chemical run-off from cultivation sites to nearby natural water sources, contaminating rivers, lakes and streams. Water with dissolved pesticides entering the soil can also leach contaminates deep into the groundwater supply through the vertical descending displacement of materials through the soil profile. These contaminated water sources can then cause secondary contamination of crops.

Groundwater Contamination

“The degree to which applied pesticides reach the groundwater is determined by factors like land-management practices, chemical and biological degradation rates and hydrogeological conditions like the thickness of the unsaturated zone of the soil profile, which can vary between different soil types…

There are several forms of water source contamination. This post will focus primarily on groundwater and surface run-off contamination. Within a typical soil profile, there are five layers called master horizons. Not all five horizons are present in every soil type, but every soil type displays at least one horizon. Below those five horizons lies bedrock, which is usually the parent material for the soil that lies above. Groundwater is the subsurface water that fills in the cracks of the bedrock and the spaces between individual soil particles throughout the soil horizons. These spaces are referred to as pore spaces.

Groundwater can move freely under the influence of gravity, and often will move horizontally towards stream channels. The degree to which applied pesticides reach the groundwater is determined by factors like land-management practices, chemical and biological degradation rates and hydrogeological conditions like the thickness of the unsaturated zone of the soil profile, which can vary between different soil types (Toccalino et al. 2014).

Variations in soil types can influences water contamination. Some soils may be more susceptible to the leaching of pesticides as water infiltrates the surface horizons. Infiltration is the process in which water falling onto the ground enters the soil through absorption. The rate of infiltration decreases as the soil becomes more saturated, and once the soil is fully saturated, infiltration can no longer proceed and the water is transported across the top of the soil as surface run-off.

A study by the U.S. Geological Survey’s (USGS) National Water-Quality Assessment (NAWQA) Program tracked changes in pesticide concentrations in U.S. groundwater over the course of nearly two decades, from 1993 through 2011. The assessment by Toccalino and her team revealed that pesticide concentrations infrequently surpassed human-health standards. However, there may still be a concern for secondary contamination of crops like Cannabis, which could potentially lead to detections of pesticides in flower samples submitted for regulatory analytical testing.

The measure of a pesticide’s capacity to dissolve in water is known as pesticide solubility, or pesticide mobility.As water moves through the soil, dissolved pesticides are drawn into the soil profile during infiltration. As of 2015, information on the plant uptake of soil-persistent pesticides was largely deficient, and the research that is currently available targets the detection of residues in edible plants like cucumbers, leafy greens and potatoes (Hwang et al. 2015). Recent studies have been initiated based on the alarms of reported pesticides in organic agricultural products, which seem to be an increasingly problematic issue for organic farms that do not directly apply pesticides to their crops.

As soil is eroded, soil particles also known as sediment are more easily transferred by water and wind. Chemicals attached to those eroded soil particles and dissolved in water are also transferred. Soil types that are sandier than clay, for example, have a greater rate of infiltration and water loss. Sand has a larger particle size than silt or clay, creating relatively bigger pore spaces between the particles of sand, leading to a greater rate of infiltration of water through the soil. As soils become more eroded, finer particles like silt and clay are moved away while larger particles like sand remain. Eroded soils are therefore more prone to infiltration and water loss and move water and dissolved chemicals in and out of the soil profile more rapidly (Brady and Weil, 2010).

Drawing water from wells for use in agriculture without proper filtration could be problematic. Wells draw water from deep below the soil surface where groundwater moves freely. Using contaminated groundwater to supply water through an incorrectly maintained delivery system could potentially cause secondary contamination. The cleanup of contaminated groundwater is nearly impossible and contamination can proceed for many years.

2 November 2017

The Tradition of Mold Count Testing for Herbal Products

Here at EVIO Labs, we field a lot of questions from Cannabis producers and retailers about mold and mold counts. Total mold count testing is a fundamental part of basic quality assurance for most herbal medicine commodities. Whether we’re looking at Russian Rhodiola, North American Echinacia or Kava paste from Vanuatu, you can bet that the commodity buyer will expect a mold count result (among other things) from and independent laboratory. At one time, mold count testing was required by rule, in Oregon, for all Cannabis being transferred to dispensaries. Despite that up to 15% of batches of Cannabis ‘flower’ failed mold count testing, mold count testing disappeared from the requirements sometime early in 2016. Despite this, some Oregon Cannabis wholesalers and retailers still required a mold count test for their own Quality Assurance purposes.

Basic mold count testing in bulk herbs, Cannabis included, is relatively simple and typically cost less than $50. The principle of mold count testing with herbs and herbal preparations is to shake a quantity of the sample with a buffered water solution and then ‘plate’ some of that liquid on a petri dish containing a general-purpose agar media that will germinate molds and mold spores. You can plate the liquid on either a petri dish or, more commonly, on a disposable petri-like device called 3M PetriFilm®. PetriFilm is like a dehydrated petri dish formed on a card. When a watery extract of the herb or herbal preparation is plated onto the PetriFilm card, the water rehydrates the agar which germinates the spores. After 48 hours incubation, any germinated fungi or fungal spores appear as a colored colony spot which can be counted. Data is reported in Colony Forming Units per gram of sample (CFU/g). Basic mold count assays are typically non-specific—meaning that it is a metric of all active molds and spores, both harmful and harmless. In truth, almost no herbal commodities will have NO mold count. In general, acceptable limits for mold counts in raw medicinal plant material intended for processing and raw herbal material intended for internal use are 10,000 CFU/g and 1000 CFU/g, respectively.

The World Health Organization states the following, with respect to the need to test herbal medicines for microbiological contamination:

“Herbs and herbal materials normally carry a large number of bacteria and molds, often originating in soil or derived from manure. While a large range of bacteria and fungi form the naturally occurring microflora of medicinal plants, aerobic spore-forming bacteria frequently predominate. Current practices of harvesting, production, transportation and storage may cause additional contamination and microbial growth. Proliferation of microorganisms may result from failure to control the moisture levels of herbal medicines during transportation and storage, as well as from failure to control the temperatures of liquid forms and finished herbal products. The presence of Escherichia coli, Salmonella spp. and molds may indicate poor quality of production and harvesting practices”(1)

Mold counts are one basic measure of herbal Cannabis and Cannabis products. While many molds typically found in cured cannabis are not regarded as being pathogenic, too much natural mold content can spoil the organoleptic quality of the herb (appearance and aroma). More seriously, high mold count can be a sign of too much time at a high moisture content, e.g., improper curing. In some cases, toxic molds can also be present. Toxic mold species such as Aspergillus can cause potentially fatal respiratory infections in immunocompromised patients and it can also produce significant quantities of aflatoxin, ochratoxin and other mycotoxins that are persistent and seriously toxic–even after processing or even sterilization.

Despite once being a required quality assurance test in Oregon, mold count testing is no longer required. In other legal Cannabis states, mold counts and other microbiological contaminant checks are required testing (California, Colorado, Massachusetts, Nevada, etc.). If you think basic mold testing is important, you should ask your Cannabis producer, wholesaler or retailer about it and let them know you value it as a metric of quality and safety.


WHO Guidelines for Assessing Quality of Herbal Medicines with Reference to Contaminants and Residues. ISBN 978 92 4 159444 8. World Health Organization 2007

2 November 2017

Why You Should Rethink Shopping Based on THC Content

“…many consumers tend to just buy…the highest THC number. And as a result, high THC numbers fetch more money.”​

Imagine you’d like a nice alcoholic beverage or two to help you wind down after a stressful week, or just to have fun with friends. Do you set out to purchase the drink with the highest alcohol content because you will get the most bang for your buck?

Probably not. People typically make alcohol buying decisions based on flavor profile, presentation, quality of the beverage, and what they happen to be in the mood for at that moment. Precise alcohol content measurements rarely come into play in the purchasing decisions.

Paradoxically, this is exactly what happens in cannabis dispensaries every day. Absent much information about the dizzying array of strains and products available in a dispensary, many consumers tend to just buy the cannabis with the highest THC number. And as a result,high THC numbers fetch more money.

“Choosing flower based on THC alone…is bad for the industry.”

Choosing flower based on THC alone is not helpful for the consumer, and frankly, is bad for the industry.

Here’s some reasons to look beyond the THC value when making purchasing decisions:

  • THCa (which converts to THC when cooked or burned) is just one of over a hundred cannabinoids that exist in the cannabis plant. Cannabis plants also have CBDa, CBN, CBG and numerous other cannabinoids that work together to produce different effects. Further cannabis features hundreds of terpenes, a class of compounds that provides a variety of aromas and effects, that add to the overall “entourage effect” responsible for any effects experienced by the consumer. Cannabis and its effects can be quite complex, and you may find that a low THC strain might bring you exactly the effects that you want.
  • If you live in a state where testing labs aren’t regulated, the THC number on the package might be inaccurate. In California, for instance, lab tests are not yet highly controlled, so there is a lot of room, and incentive, for putting a THC value on the package that is higher than an actual representative sampling of the batch would provide. Growers may bring in a sample from a flower that they believe is high in THC, but put that test result on lower THC strains. (This is likely to change next year with upcoming changes to testing and labeling regulations.)
  • THC values are not as precise as they might seem. Even among the most well-intentioned growers and the best labs, there is a potential variance in results by as much as 5% either way. So a cannabis flower labeled 18% could be anywhere from 16% – 20%. To further complicate things, the cannabis plant exhibits phytochemical polymorphism, meaning it does not produce the same concentrations or variety of chemical compounds uniformly throughout the plant. So when looking at samples side by side, keep in mind that a few points difference between them is effectively no difference.
  • On average, cannabis flower RARELY tests over 25% THC. If you walk into a dispensary and see several strains on the menu with very high test results, there is a good possibility the numbers have been inflated. And the dispensary probably isn’t supporting a lot of the growers that are producing a wider variety of lower THC strains, some of which might be quite appealing to consumers.

Why is all this THC emphasis bad for the industry?

Since consumers have little else to go on, they are putting their money in the high THC strains. Some dispensaries are catching on to this and keep test results behind the counter so consumers don’t immediately gravitate towards this number. However, it still happens.

As a result, high THC strains fetch a higher price in the market. And that causes unintended consequences including causing growers to “shop around” for labs that will provide the highest results, which in turn provides incentive for labs to compromise their scientific integrity to find ways of inflating THC numbers in the hopes of keeping their client’s business.

While legitimate labs will not fudge results, they do come under pressure, often indirectly, but sometimes directly with threats of non-payment and certainly lost business if a low test result is reported. It is possible that a nefarious lab employee could cheat the system behind the scenes. Regulators in Oregon and other states have put controls and routine auditing in place to minimize this practice, however it still could happen – particularly in states that do not yet have testing regulations in place, such as in California.

So the next time you visit your favorite dispensary, consider avoiding buying cannabis on THC content alone, and instead find the products that have the flavors, aromas, and other features you enjoy. You might just find in your experience that a 14% flower may come off as feeling stronger than that 30% flower that would have cost more money. And if the 14% flower doesn’t seem strong enough with two hits, take a third, and enjoy.

2 November 2017

Edibles Testing – Why are the results so variable?

EVIO Labs tests a wide range of products that go far beyond cannabis flower and oils. We get products as varied as elaborately decorated chocolate truffles to ice cream sandwiches and even granola. Tests results on these products have come back with widely varying potency results. This summer, EVIO Labs Regional Lab Director Ellen Parkin and Chemical Engineer Jeremy Campbell set out to identify the cause of these variations. Their results were presented to the at the Institute of Cannabis Research Conference in Pueblo, CO. Their presentation Sources of Uncertainty in Cannabinoid-Infused Products highlighted the many factors involved in analyzing different types of edibles, and identifying what could cause variability in test results. They found that testing uncertainty is less than 0.1%. However, variations that occur during the processing and manufacturing process can be much higher – thus it is important for producers to ensure they are making a highly homogeneous product prior to sending their edibles to test. A synopsis of their study is included here.​

Sources of Uncertainty in Cannabinoid-Infused Products
by Ellen Parkin, MS and Jeremy Campbell, MS

As states across the United States legalize recreational cannabis use, cannabinoid-infused edibles have increased in popularity. For many consumers, this is the first impression and experience of the cannabis industry. Edibles, however, have gained a reputation for being notoriously variable in their potency (think Joe Rogan’s story about gummy bears in his recent Netflix special). This situation has left edibles processors and analytical laboratories scrambling to find and address the sources of variability in edibles potency.

EVIO Labs is accredited by the state of Oregon to perform potency testing and we pride ourselves on providing consistent results of the highest quality. To address the mentioned edibles potency concerns, we started asking questions. Questions like: What are the sources of variability in edibles potency? Are these tales of edibles disasters an indicator of product variability or consumer inexperience? Can we, as laboratories, successfully measure all the active THC from an edible? Can we improve our testing techniques?

We know that the concentration of active THC in edibles is extremely low. In Oregon, the recreational limit for cannabinoid infused ingestibles is 5 mg of THC per package. Therefore, if the total weight of the ingestible is 15g (pretty standard for gummies and chocolates), the target THC concentration of THC within the product is 0.33 mg of THC per gram of product. We suggested that this low dosage may be in part to blame for variability in at provides the analytical lab with a very low tolerance for variability of results. To put this in perspective, a 15mg piece dosed with concentrate of average 70% THC would need 0.47 mg (0.00047 g) of concentrate for a dosage of 5 mg.

In the life cycle of testing, the plant material is tested for potency, which determines if it will be processed into cannabinoid extract. Once extracted, the concentrated cannabinoids can be processed into a format to introduce it to the edible process. Finally, the edible itself is tested. At each step, errors and non-homogeneity of the samples will affect the final product.


EVIO Labs examined 2 sets of sample variation: between units and within units. This allowed us to dive into the analytical uncertainty and sources of variability around edible extractions. To determine these sources of variability, we utilized 6 different edible systems (3 model, 3 commercial) and 4 solid-liquid extraction techniques. We determined the most appropriate extraction for each sample type and examined the inter and intra variability within the commercial sample sets.

We analyzed chocolate, gummies, and baked goods (cookies and brownies) as our commercial products. From sample to sample, the gummies were the most variable. The cookie was the least variable. We then examined each sample type in fractions. Overall, increasing the sample fraction (i.e. decreasing the sample size) increased the %RSD (Relative Standard Deviation) between the samples. All samples were analyzed in triplicate.


We developed model systems to specifically replicate fat, protein, and sugar systems that one might see in an edible matrix. Each was dosed in a controlled lab environment and expected recovery was calculated. The model systems were extracted using 4 different extraction methods (MeOH, Quechers, 1:3 H2O:MeOH, n-hexane) and analyzed with our validated EVIO cannabinoids method. Sugar showed great recovery across all 4 extraction types. Protein did well with all extraction types expect hexane. Fat had adequate recovery with MeOH and Quechers extractions, had excellent recovery with the hexane extraction and had terrible recovery with the 3:1 MeOH:H2O extraction.


Finally, we move on to our examination of uncertainty. Initially, variability within the unit was included – however laboratories can take steps to decrease that through homogenizing the sample or extracting it entirely. Recovery values from the extraction process are < 10% in each calculation, and analytical uncertainty is < 0.1%. Overall, the biggest contributors to sources of uncertainty in edibles are the production methods and the variability unit to unit.

2 November 2017

New Testing Rules Coming in California!

EVIO Labs is already testing cannabis at our laboratory in Yuba City, CA in accordance with the current requirements, which means we’re analyzing for a list of pesticides, solvents, microbiologicals and cannabinoids. When recreational marijuana becomes legal in California as of January 1, 2018, most experts agree that testing is going to be a different thing entirely.

Exactly what the new regulations will entail is still up in the air, but we do have some indications about changes that will be implemented based upon the current draft rules. The draft includes, amongst other things, a list of 66 pesticides, 22 solvents and heavy metals that we will test for. Regulators have also provided some color on the proposed California process which happens to be similar to what we are currently doing in Oregon.

We are also aware that new pesticide rules will be released in November, which will provide some additional clarity on the upcoming regulatory environment. It is anticipated that the next iteration of pesticide rules when they arrive next month will increase the action levels (the levels at which pesticides result in a test failure). In Oregon, approximately 25% of extracts and concentrates failed during the first months of new, stringent pesticide testing rules, and the action levels in Oregon are higher than what California is proposing.

This is particularly important for growers to recognize and address as quickly as possible because failed tests obviously eat into the bottom line. The good thing is that there is a decrease in the failure rate throughout the year as growers learn what not to do with their plants with regards to pesticides and manufacturers become more discerning about their source of product.

Although it’s a lengthy list of solvents that we will test for, we don’t run into too many failures from qualified manufacturers, provided they make sure that their product is finished well. In Oregon, ethanol was finally taken off the list because it is impossible to have a tincture without it.

We also will be testing for the heavy metals Lead, Arsenic, Mercury and Cadmium; microbiologicals (i.e. salmonella, aspergillus, e. coli); mycotoxins; water activity and flower moisture content; and filth and foreign material to ensure a consistently safe consumer product. When it comes to plant matter, testing for water activity is done first. If the water content is too high, the sample fails and we won’t test again until the flower is sufficiently dry.

In general, we suspect the process is likely going to be similar to other states today. A typical scenario goes something like this. A distributor contacts us to request testing. The distributor is responsible for chain of custody and thus indicates in METRC that samples are properly prepared for testing. They will complete documentation indicating requisite testing.

Our personnel prepare a sampling plan based upon the provided testing information and then go pull samples from batches at the distribution point. The temporary rules in CA provide guidance on the sampling process, such as pulling product at specific increments randomly throughout each batch. Again, the distributor is responsible METRC input, with our team tagging and labeling product.

At the lab, the comprehensive testing process begins, with each test requiring its own methods and equipment. We duplicate each test and look for variances to ensure the results are consistent, without large deviation. Lastly, we analyze the data, run it through a long list of quality checks, prepare and deliver certificates of analysis to the customer electronically and submit notification of test results in the METRC tracking system.

We use an online portal (www.confidentcannabis.com), where customers can see all the test results, as well as utilize other services, such as viewing testing statistics from across the U.S. and a wholesale price module that allows for market price comparisons of similar products.

Once the data is uploaded in METRC, the batch is officially able to be released for sale and transfers of tested product are allowed through METRC.

That’s the condensed version and we’ve drawn some conclusions based upon our expertise of laws in states that we already conduct business, our best practice policies and draft proposals already brought forth in California. One thing is certain; it’s going to be a dynamic, vibrant marketplace, the biggest in the world in fact, and we foresee very regimented regulatory oversight with respect to all aspects of the market, including the testing arena.