Hemp Pesticide Use

Ever since the 2018 Farm Bill legalized commercial production of hemp, state and federal regulators have found themselves playing catch up with production practices. That dynamic was on display when state and EPA officials gathered for the State FIFRA Issues Research and Evaluation Group (SFIREG) in Arlington, Virginia, on June 3-4.

Officially, hemp production is legal in most states now. Practically, producers have very few answers on how they can safely grow the crop, particularly in the absence of many fungicides, herbicides and insecticides labeled for use in hemp.

«We’re in a situation where production is already happening,» said Liza Fleeson Trossbach, a Virginia pesticide regulator who spoke at the meeting. «The cart is way ahead of the horse with the Farm Bill and all these other issues coming up. We’ve got a lot of angry people in Virginia right now.»

At the meeting, EPA officials admitted they are scrambling to take the initial steps to make pesticides legal and safe to use on hemp crops. In the meantime, state regulators and Extension offices are in a holding pattern, unable to identify or recommend many pesticides to farmers eager to move forward with a new cropping opportunity.


In order for hemp to be added to a pesticide label, companies must submit tests to the EPA showing that, at labeled rates, the chemicals will not leave residues beyond a level that EPA has deemed safe.

The problem is that EPA does not have data yet to know exactly what pesticide residue levels are safe on hemp products, particularly those intended for human consumption.

Hemp and marijuana come from the same plant: cannabis. The hemp legalized for production in the Farm Bill is defined as cannabis plants that have THC levels of 0.3% or lower on a dry weight basis. Often called industrial hemp, this type of cannabis is used primarily for seed and fiber production or cannibidiol extract — known as CBD, which can be ingested for medicinal purposes.

Safe levels of pesticide residues on hemp products will vary depending on the end product — seed, fiber or CBD, noted Cary Giguere, a Vermont pesticide regulator who spoke at the SFIREG meeting.

«If you’re extracting CBD, you’re also concentrating whatever pesticide residues are on it,» he explained.

To complicate matters, the EPA is still waiting on other federal agencies to weigh in on hemp regulation, such as the FDA. Last week, that agency held a hearing as part of an ongoing effort to decide how to classify and regulate cannabis-derived products such as CBD.

«There are cascading effects depending on how FDA makes this call that we’re keeping an eye on,» said Ed Messina, deputy office director at the EPA’s Office of Pesticide Programs. «It will impact the extent to which we need to look at how human consumption [studies] are done. If it’s just a medicine or drug, FDA will have bigger role in setting those limits, whereas if it’s a food, we’re going to have a bigger role.»


There are six federally registered pesticide products that currently list hemp on the label, all plant growth regulators or synergists intended for use in seed or fiber production of hemp, noted Fleeson Trossbach. Since they were registered before the 2018 Farm Bill, they do not contain food tolerances for residue levels, however, she added. «We all have human health concerns, obviously, specifically if things are going to be ingested,» she said.

Because some states have been growing cannabis for years, either for industrial hemp or marijuana production, there are other pesticides out there with a history of use on the plant, state regulators noted.

Most of these are chemicals that are exempt from the tolerances that EPA typically sets on pesticides, because they are classified as minimum risk pesticides — for example, hydrogen peroxide, which can be used as a fungicide. See more on minimum-risk pesticides here: https://www.epa.gov/…

States where producers have been growing marijuana have a leg up in this arena. For example, the Washington State Department of Agriculture has posted and is actively updating a list of pesticides that can be used legally on hemp within the state, primarily tolerance-exempt ones that are labeled for use on unspecified garden, herbs and oil-seed crops. See it here: https://cms.agr.wa.gov/…Other states, such as Colorado, have developed state rules on pesticide use specifically for cannabis production. See Colorado’s here: https://www.colorado.gov/…

For legal reasons, however, other state regulators are hesitant to send out lists of pesticides to hemp producers, since they are not supposed to make recommendations of particular products and brands, noted Tim Drake, a South Carolina pesticide regulator.

Producers’ best bet, at this point, is to consult carefully with state Extension offices and departments of agriculture to find out what pesticides are legal and safe in the eyes of their local authorities, Fleeson Trossbach said.

«I don’t think any state wants to set up a grower for misuse,» she said.

Read the original article at Progessive Farmer