Editor's note: This article was originally published during the 2018 wildfire season. Read "California Wildfires Continue to Ravage State Agriculture, Including Cannabis Farms," published in September 2020, here.
As more than a dozen wildfires continue to burn across California, cannabis cultivators affected by the blaze face challenges ranging from the health and safety of their employees to the potential destruction of their facilities and crops. Consumer safety and lab testing will also become significant concerns as cannabis grown in affected areas hits the market.
“When you start getting into how [it’s] going to affect product and manufacturing and production, this is the big variable,” Jon Vaught, CEO of Front Range Biosciences, a Colorado-based agricultural biotech company, told Cannabis Business Times. “It depends on where the wind’s blowing, what your situation is, where you’re located. You could be right next to a fire and have no issues at all, or you could be ten miles from it and have your building filled with smoke. It really just depends on the weather.”
Smoke can stress or even kill the plants—especially those in outdoor or greenhouse operations—and the residue left behind can pose problems for lab testing and consumer health.
“Smoke taint is the most obvious and the most apparent threat to cannabis as [it’s] exposed to these forest fires, and that’s something you’re going to be able to readily tell from just qualitatively examining the cannabis,” said Josh Wurzer, president of SC Labs, which has operations in both California and Oregon. “So, that’s certainly a concern—just ruining the flavor of the cannabis.”
Smoke from municipal fires that burn buildings and other man-made structures can be more harmful than forest fires that burn trees and foliage, Wurzer added. “[When] cannabis [is] growing indoors in city limits or near other buildings and the fire comes into the city like it is in Redding or like it did last year in Santa Rosa, you have concern that when you have buildings on fire, the smoke … has a lot more potential to contaminate the cannabis with toxic chemicals.”
Pressure-treated wood, for example, contains chemicals like chromium and arsenic, which can settle on cannabis crops in the soot and ash from fires.
Fire retardant can also pose threats to cannabis crops and their water sources, said Lydia Abernethy, director of cultivation science for Steep Hill Labs, which has a California office in Berkeley. “If your product has been exposed to [a fire retardant], you should not consume it or release it into the cannabis market. If Phos-Chek or other fire retardants were dropped on or near your property, it’s important to monitor your waterways to make sure there’s no persistent problem with chemicals in your water.”
Each lab uses its own validated testing methods, Vaught said, so it is difficult to predict if these chemicals would be detected during testing and how fire damage could impact state-mandated product testing overall. “It depends on how well-aware they are of it,” he said. “Are they testing for potential contaminants that might come in through the smoke, or do they recognize that they need to test for other contaminants, and that’s an additional contaminant that they wouldn’t normally test for? There are so many questions around the specifics of that that it’s hard to give a super clear answer on how it might affect it, but it certainly could, and it’ll have to be taken on a case-by-case basis.”
Testing labs are required by their particular state regulatory agencies to test for a specific list of contaminants. Anything outside of that list—which in California, for example, contains a very specific roster of cannabinoids, mycotoxins, pesticides and more—will not likely show up in laboratory test results.
Beginning on Jan. 1, 2019, California labs will be required to test for heavy metals in cannabis, including arsenic, Wurzer said, and the state labs currently test for other chemicals that could potentially be produced during municipal fires, such as benzine, but only in concentrates. California labs are also currently conducting required foreign material inspections, which would detect soot or ash from fire damage, Wurzer added.
“As far as I know, none of the labs have developed a test that is specialized for indicators of fire,” Wurzer said. “To test for other things, you have to develop and then validate a method for that testing, so … unless there’s a need for … the tests, chances that someone can do the test are pretty unlikely. So, all we have really at our disposal is looking at the test results [and being] on the lookout for those certain indicators—is there an elevated level of arsenic? Is there an elevated level of benzine?”
It also remains unclear whether contaminants from wildfires could cause false positives or false negatives in pesticide testing, Vaught said. “The likelihood that specific pesticide residues could show up and trigger a false positive [is] definitely a realistic possibility. … I think the likelihood of it would depend on what was actually burning.”
For example, if a forest of pine trees that has never been sprayed with pesticides burns, it is unlikely that smoke or soot from that blaze would cause false positives in cannabis pesticide testing, Vaught said. On the other hand, if a field of corn that has been heavily sprayed is burning, by-products and combustions of those pesticides could show up in the test results of nearby cannabis products.
The bigger issue, however, is contamination from these potentially toxic substances and how it might affect consumer safety, Vaught said. “Some of them can be extremely toxic, so getting large amounts of soot and combustion by-products on your plants or on your product would definitely be something you would want to avoid, whether it triggers a regulatory test failure or not. That would just be good manufacturing practice and putting out safe products for your consumers and minimizing your risk and potential liability should something go wrong.”
And even if cannabis affected by the fires is safe for sale into the market, it may not be desirable for consumption or even extraction, Wurzer added.
“Typically, heavy smoke or particulate exposure degrades the product quality to such a degree that most people won’t knowingly purchase it,” Abernethy agreed. “As fires continue to affect cultivators across the state, I’m sure we’ll see products (especially flower) fail regulatory testing—like filth and foreign materials testing due to the presence of ash, cinders, dirt and mold. If people are interested to determine if their product might fail regulatory testing, we encourage them to contact Steep Hill for pre-regulatory analysis. Don't lose hope entirely—if your crop has been affected by fire exposure, there are a few remediation routes to making successful, market-appropriate products.”
If a product does fail testing, California has a remediation policy that allows cultivators two remediation attempts and additional re-tests, she said. Steep Hill warns growers against using chemical products to strip away smoke and ash particulates, however, as these can cause additional product quality and safety issues. “We strongly caution anyone from further contaminating product by stripping it with chemicals to try to wash off the smoke,” she said. “That’s not a sound way to go about remedying this problem.”
To avoid the possibility of ongoing testing failures and consumer safety issues, a cultivation facility needs to be cleaned on some level after being exposed to a wildfire, Vaught said, depending on the amount of damage—how much smoke and soot has been deposited. “It could be everything from a low-level of contamination and cleaning required, where you have to go in and just wipe down your walls and get rid of all your plants and clean out your hydroponic systems … or whatever … different components that could absorb soot and smoke, all the way to heavy contamination which requires pressure washing, replacing dry wall, replacing ceiling tiles—replacing anything that absorbs large amounts of contaminants.”
There are professional fire remediation companies that can be consulted, he added, and operators should not take this responsibility lightly. “As soon as you have something like this happen, … talk with your insurance adjuster, … talk with a local fire remediation company, … [and] get some experts on the scene so that they can help you quickly address the problem, as opposed to trying to say, ‘Well, maybe we don’t need to worry about it.’ It’s always better to err on the side of caution for something like this, and yes, it can cost a little more money, but in the long run, it protects you from creating a liability for your company with your consumers, which is never a good thing.”
Furthermore, there are the consumer-facing issues to consider. A cultivator’s testing lab should be able to have an open and transparent conversation about what it is doing in its business practice to account for the wildfires, Vaught said. “That’s what I would recommend, across the industry—more open dialogue about these important issues for not only for the industry, but for the consumers and the safety of consumers,” he said. “It’s so very critical, whether we’re talking about pesticides or combustion by-products that are toxic from forest fires, or potential food additives that may or may not be approved for human consumption—all of these different issues affect the whole industry.”
Top photo: The Carr Fire in Shasta County on July 27, 2018. Photo courtesy of the California Department of Forestry and Fire Protection.