A new Colorado state audit examines how the state oversees cannabis testing, business inspections and public warnings about health risks. Its findings point to weaknesses across those responsibilities and renew questions about how quickly regulators can identify and address unsafe products.
The audit found that gaps in oversight could expose consumers to unsafe marijuana products, according to Axios. Products sold between 2023 and 2025 were tested inconsistently for contaminants and potency, the outlet reported. In one case in 2025, potentially harmful products remained available for purchase before the Marijuana Enforcement Division issued a public health advisory.
One issue is how testing samples are selected: marijuana businesses choose the private labs that test their products, a practice the audit says raises the risk that unsafe products will not be properly flagged. Audit manager Kate Shiroff said the Marijuana Enforcement Division’s inspections are inconsistent, leaving key details unavailable for review, Axios reported.
Who Selects the Samples?
The audit’s concerns arise amid longstanding questions about Colorado’s testing controls. In reporting on the system, ProPublica found that businesses select the samples sent for testing. In 2024, state officials identified 24 cases of marijuana businesses violating testing rules, often by submitting samples that differed from products sold in stores or by using unauthorized chemical treatments, the investigation reported.
ProPublica has also reported that Colorado lacks several safeguards adopted in other legal marijuana markets to help keep contaminated products off shelves. The state’s approach to sample collection has been under discussion, but a proposed change has not been adopted.
The delays in catching problems carry real consequences for consumers. Colorado marijuana regulators have taken more than seven months on average to warn the public after a complaint was filed or an investigation began into a risky cannabis product, and more than seven months from the date a contaminated product first went on sale, according to ProPublica's reporting.
Recalls and Overstated Potency
The track record on contamination is substantial. The Marijuana Enforcement Division has issued 63 recalls since 2019 for cannabis products contaminated with bacteria, fungus, pesticides, heavy metals or other chemicals exceeding legal limits, according to the Daily Camera. Independent testing of 15 cannabis products found that 12 had significantly overstated potency labels, while four exceeded the state's limit for yeast and mold, the paper reported.
Some of the rise in flagged violations traces to expanding requirements rather than a sudden surge of bad actors. Colorado began requiring aspergillus testing in 2022, a change that contributed to an increase in testing-related violations as rules and enforcement broadened, per the Daily Camera. Even so, the state's enforcement capacity remains thin: just 27 investigators are responsible for monitoring roughly 2,200 marijuana businesses statewide, and they conducted 160 product-safety investigations in 2024, the outlet noted.
A Pattern Dating Back Years
Colorado auditors have previously documented problems with marijuana oversight. A 2023 performance review found that 36% of newly licensed retail marijuana stores examined had not been inspected within a year of approval, and that 182 stores identified as inspection priorities never received inspections during the period reviewed, according to The Marijuana Herald. The review also found regulators did not pursue disciplinary action in 23 of 44 examined violations tied to public safety.
The newly released audit covers both the Marijuana Enforcement Division, housed within the Department of Revenue, and the Colorado State Public Health Laboratory, which assists with testing cannabis products, The Marijuana Herald reported. The division is responsible for licensing marijuana businesses and monitoring product safety statewide. Separately, state rules require marijuana testing facilities to complete a self or internal audit using official checklists and to correct any non-conformances identified, according to the Colorado Department of Public Health and Environment.
What Changed After Earlier Reviews?
In a January 15, 2025, follow-up to the 2023 Marijuana Enforcement Division audit, the Colorado Office of the State Auditor said supporting documents substantiated the Department’s reported implementation status for recommendations it considered implemented or partially implemented. Sample collection is handled differently in many other markets: 26 states and the District of Columbia require lab personnel, rather than businesses, to collect testing samples, according to ProPublica. In a separate policy discussion on Feb. 6, 2026, Colorado regulators considered replacing manufacturer-selected samples; ProPublica described that change as a proposal, not an adopted rule.
Fourteen Recommendations, One Deadline
Auditors issued 14 recommendations to strengthen oversight of testing, inspections and public notifications. The Marijuana Enforcement Division agreed to partially implement a recommendation to improve its safety framework by December 2027. The audit was scheduled for legislative review this week, giving lawmakers another opportunity to consider gaps in sampling, inspections and public warnings.
