The Blind Spot in Denver’s Pesticide Recalls [Updated]

On Friday, Denver’s 19th recall of cannabis, extracts, or cannabis-infused products occurred. The Denver Post – which has done a valuable public service with its very informative reporting on the matter – is maintaining a running list of all the recalls.

An individual perusing the above list might notice that the recalls consist primarily of cannabis extractions and infused products. In fact, only 4 of the 19 recalls have included actual cannabis plant material – or the flowers that people typically smoke – in its raw, unprocessed form. Regarding the 15 recalls that consist of edibles, concentrates, and other infused products, the Denver Department of Environmental Health’s (DEH) notices will generally consist of language to the effect of, “[Marijuana Infused Product Manufacturer] is recalling marijuana-infused products that were derived from potentially contaminated plant material purchased from [Cultivation Facility].”

This is all well and good, and many have expressed the sentiment that the recalls mean that Colorado’s regulated system is working as it should by identifying quality control issues and removing contaminated products from circulation. This is true, but only to an extent. The whole truth is that Denver’s pesticide recalls have a very big blind spot.

In this post, I will leave aside issues such as the fact that the required pesticide testing written in law is not being performed due to the lack of qualified labs, that medical cannabis products are not required to be tested for pesticides at all, and that – even if required testing of products were taking place prior to their reaching market – producers select and provide their own samples. Believe it or not, none of those issues – which I’ve discussed in previous posts – are the blind spot of which I’m speaking.

To get to my point, I must first note for those unfamiliar with cannabis-infused product manufacturing and extraction that both of those processes primarily use “trim,” or the small leaves sheared away from buds to prepare flowers for sale, as their raw material.

A “trimmer” trimming cannabis flowers to prepare them for sale. The “trim” is captured in the tray in the bottom of the photo and is destined to be processed into concentrates or other infused products. Image Credit: Brennan Linsley, Associated Press

So, trim is the “contaminated plant material” being referred to in the DEH’s recall notices.

Think about that for a moment. If trim has been contaminated with pesticides, then logic dictates that the flowers from which the trim was sheared away are also contaminated.

Where, then, are the recalls of the flower associated with all of these contaminated batches of trim?

To those unfamiliar with the inner workings of Colorado’s legal cannabis system, this might seem to be an unreasonable question. After all, there are hundreds of companies that make concentrates, edibles, and other infused products. Those companies buy trim from the hundreds of cultivators in the state. Extractors and infused product manufacturers sometimes also grow their own raw material, but even those that do generally process trim from the open market as well. As such, it would be difficult to track packages of plant material being shuttled between all of those different points. It’s no wonder that the dots between contaminated trim and flower cannot be connected, right?


One of the most frequently boasted-about features of Colorado’s system is its “seed-to-sale” tracking system, called METRC (though it was called MITS upon its inception), developed by the company Franwell. This system involves tagging every baby plant with a label that contains an RFID chip, which stays with it until harvest. Once harvested, the plants taken down together are reported in the system by weight as a “harvest batch.” The plants are then dried and trimmed, with the weights of the dried flowers and trim subsequently reported into the system. Those final weights then remain in a “batch” in the system, where their totals are drawn down whenever a quantity of product from that batch is transferred to an associated dispensary for sale or to an infused product manufacturer for further processing. The important point for our discussion here is that both dried flowers and trim sheared away from those flowers should remain part of the same harvest batch, or should at least be able to be associated due to the nearly identical dates and times at which they were entered into the system (operations are required by law to reconcile all inventory in METRC daily by the close of business).

Franwell’s METRC system was designed to prevent diversion of cannabis produced by legal companies into illicit channels and to establish a record of the supply chain for instances such as pesticide or contaminant recalls, similar to the manner in which bar codes can be used to track contaminated food products that need to be pulled from shelves. In the words of METRC’s own website, the second feature of the system listed is that it “promotes public safety and patient product safety with traceability.” For whatever reason, neither Colorado’s Marijuana Enforcement Division (MED), which oversees and enforces the use of METRC by cannabis businesses, nor Franwell itself, is taking the step of connecting the dots between the contaminated trim that went into contaminated infused products, and the associated tainted flower, which presumably went onto dispensary shelves for sale to patients and consumers.

In short, a system for which the state is paying millions; from which businesses are required to purchase thousands upon thousands of non-reusable plant tags; to which businesses are compelled to devote significant labor hours; and which was designed specifically by Franwell to not integrate with any other software programs that were already in use by cultivation facilities and dispensaries, making running a cannabis business even more difficult than it is already; that system is not doing one of the two main things that it is intended to do. Or, perhaps it is, and the MED is not monitoring and employing it appropriately. The MED has been conspicuously absent in the pesticide recall process, which was initiated almost entirely by Denver city departments, and to my knowledge has yet to hand down any discipline or penalties for illegal pesticide usage by the dozens of business that have been caught using such potentially dangerous materials.

In any case, due to the public health risk created by off-label pesticide usage on cannabis and the significant amounts of public and private money being paid to Franwell for a system that every Colorado cannabis business is required to use, the inability of the state and said system to perform the task of identifying additional contaminated product (flowers) that originated from the same harvest as already-known contaminated products (the trim processed into recalled edibles and concentrates) is worrying and perplexing.

Cannabis consumers and patients should be confident that products produced in an unsafe manner are not making their way onto dispensary shelves. That was one of the promises of Franwell’s METRC – and of legalization overall – that is not currently being kept. It is hoped that, by shedding light on this large and dangerous blind spot in Denver’s pesticide recalls, the necessary reforms or adjustments in enforcement are made to ensure that any tainted cannabis associated with already-recalled product can be removed from circulation.

There are already far too many gaps in the state’s quality-control system; in the very near future we need intelligently-formulated, universal testing standards to be required of all labs, in addition to proper sampling protocols to ensure that producers cannot simply sidestep any regulations put in place, and other measures to guarantee that contaminated product does not make it to market in the first place.

Right now, though, shedding light on and addressing the blind spot by which contaminated flowers are slipping through the cracks to potentially poison unwitting consumers would be an achievable first step based on the currently available tools, resources, and systems now in place.

Update (2/8/16): A message yesterday from the Denver Department of Environmental Health provided the following information: “The reason we did not name the cultivator in the Caregivers recall was because they mixed trim from four cultivators, and we are still working on this part of the investigation. It wouldn’t have been fair to publish the names of four cultivators when we do yet know which cultivator(s) were the culprit. Getting a timely notice out to consumers about the recalled products was the first priority.” Thanks for that clarification and for the DEH’s work overall to protect public health. I have removed the statement above that previously identified the source(s) of the trim as unknown in the most recent recall relating to Caregivers for Life.


5 thoughts on “The Blind Spot in Denver’s Pesticide Recalls [Updated]

  1. Anatoly Chlenov

    The question is of limit or tolerance for pesticides which also relates to the sensitivity of the test method used to determine the concentration of pesticide(s) in the sample in question. Extraction magnifies the concentration of pesticide(s) as it removes all of it from the large volume (weight) of the trim relative to the volume (weight) of the flower this failing the concentrate doesn’t automatically mean failing the flower – the question is in the tolerance of the method. In a typical agricultural product the allowed limit is 10 PPB. What is the allowed limit in the concentrate? Flower?


    1. Hi Anatoly, thank you for your comment. You make very intelligent observations regarding the concentration of pesticides during the extraction process and, in regard to tolerance levels on the raw plant material, I would take your point in regard to most conventional crops. To address your ultimate questions, due to the lack of research on cannabis, no scientifically-based tolerance levels have been established; we just don’t know what is safe and what is not. My position – which you can read in full in a newer post, “Pesticide Position Statement” – is that until we have that concrete research, it is better to be safe than sorry and not tolerate any level of residue from restricted use pesticides on cannabis. As I’ve stated before, with proper planning and procedures, it is absolutely possible to consistently bring in high-quality, pest-free crops without chemical pesticides of the types being found in recalled products. It might take a little more conscientiousness and effort, but I think it is worth it to make sure that no one is needlessly exposed to potentially harmful materials.


      1. Anatoly Chlenov

        I agree 100%. Any chemical pesticide detected must make the product unsellable. The question is who and how is going to police it.


  2. METRIC is a bad joke. It does not accurately track seed to harvest, nor does it provide an audit trail for contaminated cannabis. Better solutions were presented to DEH three years ago and rejected. They wanted METRIC.


    1. Hi Peter, thanks for your comment. Just one question for you: Do you mean the MED, rather than DEH? I was not aware that DEH played a role in selecting Franwell to provide tracking services, but I could be wrong as I was not in on those discussions; I was still pretty focused on my previous facility at that time and had not yet gone to too many industry meetings.

      Anyway, I understand the frustration. But, to be clear from my end, I’m not saying that METRC cannot work – it absolutely can – but that certain modifications in approaches to its administration and enforcement are necessary for it to serve the purposes for which it was intended. Honestly, no software can do it all by itself, and we shouldn’t expect it to; there must be people behind the scenes monitoring the data and checking up on anomalies. I understand that Franwell recently hired a consultant from the cannabis industry (not my group), which I think is a good sign that they are trying to work out some of the kinks that have arisen. Productive collaboration between the industry and regulators is essential for success, and that’s what I’m trying to get going by calling attention to some of these issues.


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