Audit finds flaws with Colorado’s marijuana testing framework

Colorado’s regulatory framework to test marijuana for contamination and warn consumers about risks has significant gaps, a state audit found.

The recently-released audit focused on problems with product testing and inconsistent monitoring from the Marijuana Enforcement Division. Auditors did not find evidence of widespread health and safety risks, but the framework is not airtight.

Colorado voters approved recreational marijuana in 2012. MED, within the state’s Department of Revenue, licenses businesses and oversees compliance with marijuana rules and laws.

“It’s really a combination of factors that impacts MED’s ability to identify public safety risks and to ensure that businesses comply with safety requirements,” audit supervisor Catherine Friday told members of the Legislative Audit Committee on Monday. “As a result, there’s an increased risk that marijuana products sold in Colorado may have contaminants or may inaccurately list potency.”

Businesses select their own samples, for example, and send them to private labs for potency and contaminant testing. Twenty-four other states with legalized marijuana do not allow self-selected samples and instead rely on a third party.

“Is that something that’s going to be addressed?” Sen. Rod Pelton, a Cheyenne Wells Republican, asked. “Because if I’m a shady character, I know which products I’m going to sample and which ones I’m not. That’s a pretty gray area to me.”

Kyle Lambert, deputy director of the marijuana division, said it’s a topic the division has researched extensively but ultimately decided against changing this year. One of the reasons is the logistics and cost challenge of getting to rural businesses around the state, he said. Third-party collections also do not guarantee samples are representative of a business’s entire batch.

The division also does not have the resources to conduct on-site inspections for every business every year, though it has improved the percentage of inspected businesses in the past three years. The division’s own goal is to inspect every two years.

The audit also found that the division sometimes does not issue timely safety advisories for products that could cause health concerns, and affected products could remain on shelves for months. Auditors found that between 2023 and 2025, potentially harmful marijuana products were on the market for over seven months on average before the division issued an advisory. The average timeline improved in 2025 when regulators revised advisory guidelines.

Auditors recommended that the division work to make sure consumers and businesses know how to report safety concerns and continue streamlining the advisory process.

The division agreed with all of the audit’s recommendations.

“We recognize there are clear opportunities to improve through the audit’s recommendations, and we also appreciate the state auditor’s acknowledgment that it found no evidence to support claims of widespread health and safety issues with regulated marijuana products,” Dominique Mendiola, the division’s senior director, said. “The state auditor’s office recommendations will inform a constructive roadmap to further enhance how we build on these initiatives that we’ve taken and continue to carry out our mission.”

The audit included one legislative recommendation to strengthen the state’s reference lab’s role to support marijuana enforcement operations. The lab, operated by the Colorado Department of Public Health and Environment, cannot test for pesticides, residual solvents and mycotoxins, and lab officials estimate they’d need about $13 million to increase its capacity.

Lawmakers on the audit committee could vote on whether to introduce a bill related to the issue next legislative session.