2.12 Pesticide Use in Colorado Cannabis Production

2.12 Pesticide Use in Colorado Cannabis Production

A rule that exists because federal law is silent. Cannabis cultivation is legal and regulated under Colorado law but remains unlawful federally, so no pesticide label authorizes use on cannabis and EPA has set no residue tolerance for it. Rather than leave growers without any lawful pest control, Colorado adopted 8 CCR 1203-2 Part 17, which builds a permission test out of the federal tolerance-exemption rules. This is one of the few genuinely Colorado-only topics in the entire body of pesticide law.

The General Assembly anticipated the problem in C.R.S. § 35-10-112.5(1)(d), finding that although cultivating marijuana is illegal under federal law and therefore not specifically allowed by any pesticide label, cultivation is specifically allowed and regulated by Colorado law, and pesticide use in cultivation should be regulated under Article 10 and its rules rather than under local laws. Section 35-10-112.5(2)(b)(II) confirms that the preemption of local pesticide use and application rules applies to cannabis cultivation as well.

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1. Definitions That Do the Work (Part 17.01)

The definition of human consumption is deliberately broad. Because cannabis may be smoked or vaporized, a product that would be acceptable on a food crop is not automatically acceptable here — the inhalation route is expressly inside the definition.

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2. The Baseline Position (Part 17.02–17.03)

Part 17.02 states the situation plainly: as of the effective date of the Rules, there are no pesticides that are specifically labeled or have pesticide residue tolerances established for use on cannabis by the federal government or by Colorado. CDA does not recommend the use of any pesticide not specifically tested, labeled, and assigned a tolerance for cannabis, because the health effects on consumers are unknown. To assist growers, the Department publishes a list of pesticides it has determined meet the Part 17 criteria.

Part 17.03 adds a registration requirement: any pesticide used in the cultivation of cannabis must be registered with the Colorado Department of Agriculture, except for research and demonstration conducted in accordance with 40 CFR Part 172. A product on the published list that was registered when purchased but not renewed in the following registration year may be used within that subsequent registration year until gone, unless the Department has prohibited its use under Part 17.05.

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3. The Four-Part Test for a Section 3 Product (Part 17.04(a))

┌─────────────────────────────────────────────────────────────────────────────┐
│    MAY THIS EPA SECTION 3 PRODUCT BE USED IN CANNABIS CULTIVATION?          │
├─────────────────────────────────────────────────────────────────────────────┤
│  1. Are ALL active ingredients EXEMPT from the requirement of a tolerance   │
│     under 40 CFR Part 180, Subparts D and E?              ──► must be YES   │
│                                                                             │
│  2. Does the label ALLOW USE ON THE INTENDED SITE of application?           │
│     ("Site" includes any location or crop to which the                      │
│      application is made.)                                ──► must be YES   │
│                                                                             │
│  3. Does the label EXPRESSLY ALLOW USE ON CROPS OR PLANTS                   │
│     INTENDED FOR HUMAN CONSUMPTION?                       ──► must be YES   │
│                                                                             │
│  4. Are the active ingredients ALLOWED FOR USE ON TOBACCO                   │
│     by EPA?                                               ──► must be YES   │
│                                                                             │
│  ALL FOUR must be satisfied. One "no" ends the analysis.                    │
└─────────────────────────────────────────────────────────────────────────────┘

The tobacco condition is the one candidates forget, and it is doing specific work: tobacco is the closest registered analogue to a combusted, inhaled crop, so an active ingredient cleared for tobacco has been evaluated for a route of exposure that food-crop clearances do not address.

The narrow Commissioner exception (Part 17.04(b))

Notwithstanding condition 3, the Commissioner has authority to permit a product whose label does not expressly allow use on crops intended for human consumption if:

1. the active and inert ingredients are exempt under 40 CFR Part 180, Subparts D and E;
2. the label allows use on the intended site of application; and
3. the active ingredients are allowed for use on tobacco.

Note that this exception tightens condition 1 — it reaches inert ingredients as well as actives.

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4. The Other Three Pathways

[!IMPORTANT] A 25(b) exemption is not a free pass. Section 25(b) minimum-risk products are exempt from federal registration, but Colorado still requires state registration for distribution, and Part 17.04(d) still requires the label to authorize both the site and use on crops intended for human consumption. "It's just an essential-oil product" is not a compliance argument.

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5. The Commissioner's Override (Part 17.05)

The Commissioner may prohibit the use of any pesticide product for the cultivation of cannabis upon determining that such use poses a significant threat to public health and safety or the environment. This authority sits on top of the four pathways: a product that satisfies every criterion may still be removed from the permitted list.

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6. Practical Consequences for the Applicator

• Check the published list first. CDA maintains it precisely so growers and applicators do not have to run the four-part analysis product by product.
• Site language still governs. Condition 2 means the label must permit the site — greenhouse, indoor grow, outdoor field — you are actually treating, in addition to satisfying the consumption and tobacco tests.
• Commercial work still needs the right credential. Part 17 answers which product may be used, not who may use it. A person applying pesticides for hire in a licensed grow still needs a QS or CO license in an appropriate category, still keeps Part 6.03 records, and still owes any applicable WPS duties, since enclosed commercial greenhouse production of an agricultural plant is within the scope of 40 CFR Part 170.
• Local governments cannot add rules. Section 35-10-112.5(2)(b)(II) puts pesticide use in cannabis cultivation squarely inside statewide preemption.