For the first time, makers of marijuana-infused cookies, cupcakes and candies were required to submit samples to newly licensed independent labs for testing, starting Thursday.

If an individually packaged product exceeds the legal limit of 100 milligrams of THC — marijuana’s major psychoactive ingredient — it is supposed to be blocked from reaching recreational store shelves. Manufacturers can fix the problem or destroy the batch.

But the debut of mandatory potency testing for edibles did not come without problems.

Only two labs were cleared to start testing Thursday, and even those have yet to be fully certified. The state postponed another test that was supposed to begin, and edibles manufacturers are concerned about a lack of standardization and results that are all over the map.

State officials acknowledge testing will not be perfect at the start.

“For us, it always goes back to public safety,” said Lewis Koski, director of the state Marijuana Enforcement Division, part of the Department of Revenue. “It’s a necessary next step for us to ensure that the product is what it says it is on the labels.”

The new testing comes amid growing scrutiny of edible-marijuana products, with two recent deaths linked to edibles, hospital emergency rooms reporting more patients reacting badly to edibles, and state legislators and regulators considering greater restrictions.

Enforcement division officials say seven testing labs have been licensed and four are being certified — an additional step carried out with the state Department of Public Health and Environment.

To be certified, labs must meet standards that include lab director qualifications, quality control, security and sample tracking.

As of Thursday, however, none had completed the process, state officials said. Two labs received provisional certification, meaning they are in “material compliance” but not through the process.

State officials indefinitely postponed mandatory testing that was to begin Thursday for homogeneity — basically, making sure THC is spread throughout a product and not concentrated in any area. A spokeswoman said the division wants to take one step at a time to “ensure a controlled roll-out process for testing.”

Koski said earlier this week he was confident labs could handle potency testing for the roughly 40 Colorado businesses making edible products for recreational use.

But among labs and edibles companies, there was uncertainty.

“I think everybody is probably in the same situation as me — hanging back, waiting to pull the trigger on adding instrumentation or personnel,” said Joseph Evans, laboratory director of Steep Hill Halent, which says it got the green light to begin the mandatory testing.

Some edibles companies fear a backlog.

“Can the labs handle the volume in a timely fashion?” said Joe Hodas, spokesman for Dixie Elixirs and Edibles of Denver. “If what was a 24- or 48-hour turnaround (for voluntary testing) becomes a two-week turnaround, that significantly impacts our production.”

Hodas said because of inconsistent results in Colorado’s lab testing industry, Dixie is moving to lower the dosage in its 100-milligram products to reduce the risk of failing a test.

Edibles makers say samples from one batch get wildly different results from different labs. Meg Collins, executive director of the Cannabis Business Alliance, said the consistency problem can be addressed with data the state collects from mandatory testing.

“It’s important for the state to begin the program and not delay it,” she said. “If there are wrinkles, they can be worked out.”

Dan Anglin of EdiPure, which infuses food products with THC, disagrees. He supports a delay in mandatory testing. If a company relies on a test result that underestimates the true level of THC, companies could end up putting in too much, he said.

“This is a result of trying to rush something to appease public opinion, and what it’s actually doing is putting harmful public policy in place,” he said.

The state says it is working to contract with a reference lab, a sort of independent check on the process that would be used to verify the results and practices of labs conducting the tests.

Dr. Michael Wempe, director of the Medicinal Chemistry Core Facility at the University of Colorado School of Pharmacy and Pharmaceutical Sciences, said that should have come first.

“It’s extremely important,” he said. “How can you release a product to people and not know whether the label is correct?”

Ron Kammerzell, senior enforcement director for the Marijuana Enforcement Division, acknowledged that a system without a reference lab is not perfect.

“But mandatory testing and regimented testing of the product is better than no testing at all,” he said.

Other testing of recreational marijuana will be introduced in the coming months, including screening for contaminants.

Eric Gorski: 303-954-1971, egorski@denverpost.com or twitter.com/egorski