How Colorado Maintains Its List of Approved Pesticides for Cannabis Crops
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How Colorado Maintains Its List of Approved Pesticides for Cannabis Crops

John Scott, pesticides program manager and section chief at the Colorado Department of Agriculture, provides insight into the criteria regulators use to review products.

March 4, 2020

While the 2018 Farm Bill’s legalization of industrial hemp opened the door for federal guidance regarding pesticide use on the plant, only a handful of products have been approved by the Environmental Protection Agency (EPA), according to John Scott, pesticides program manager and section chief at the Colorado Department of Agriculture (CDA).

Colorado has taken matters into its own hands, and maintains a list of approved pesticides that can be used on cannabis under the state’s Pesticide Applicators’ Act.

“When we knew that recreational marijuana was going to be legalized, we knew we had to identify tools that the industry could use,” Scott tells Cannabis Business Times. “[During] initial discussions with the EPA, we started to identify what type of criteria those products would need to meet so products could legally be applied to cannabis. … We wanted to be able to use known science. The EPA has gone through and done the risk assessments on these products and identified which ones were of lower toxicity, and therefore they were tolerance exempt—the risk assessments have been done and they can be applied to commodities that would be ingested, like food crops. If they were going to be smoked, … through the risk assessment process, [the EPA] had pyrolysis studies done.”

Colorado derived its Pesticide Applicators’ Act from the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to regulate pesticide use in the state across all crops. If applicators misuse pesticide products, the Pesticide Applicators’ Act allows the CDA to issue a $1,000 fine for each violation it identifies. For second offenses, that fine can be doubled.

“We do have the authority to revoke licenses [and] issue injunctions, so it can increase past the point of a civil penalty,” Scott says.

The CDA developed a rule, which was finalized in 2017, to establish primary criteria to review pesticide products and approve them for its list of approved pesticides for cannabis.

First and foremost, any approved product must be tolerance exempt under FIFRA, since no approved tolerances have been established for cannabis yet, Scott said.

Approved pesticides must also be approved for use on crops intended for human consumption, and the CDA often checks its databases to see whether the active ingredient has been approved for use on tobacco.

“That way, we know that the active ingredient has at some point gone through a pyrolysis study or a risk assessment for it to be heated up in the process of smoking,” Scott says.

A product must also have broad label language in order to be approved by the CDA, he adds. “We’re looking for language that says it can be used on tomatoes and grapes and other crops—that broad language doesn’t limit it for use just on the crops listed on the label.”

Cannabis cultivators often bring products to the CDA for review, and if the department determines that the products meet its criteria, it adds them to its master list of approved pesticides and sends out an email announcement to notify the industry of the changes.

One to six new products are generally added to the list every 30 to 60 days, Scott says.

The CDA has built a catch-all clause into its rule that allows it to reject a pesticide that meets all the department’s criteria if regulators find that it can cause a public health threat, he adds, although no such products have been identified to date.

Now that hemp is federally legal, the EPA is starting to approve pesticide products for use on the crop, which helps the CDA in its decision making.

“A lot of them are actually already on our list, but now we’re able to specify [that they’re for] hemp and give very specific directions for how to apply those products on hemp,” he says. “But there are just a handful at this point—they just started [approving them].”

RELATED: EPA: Hemp Pesticide Approvals Pending

The IR-4 Project, an organization that performs risk assessment on specialty crops to help develop pesticide tolerances, is also working to develop federal criteria to approve pesticides for use on hemp, Scott adds.

“There’s definitely some movement heading in the right direction, identifying new tools that have previously been limited,” he says.