Marijuana under cultivation indoors where light, temperature and humidity are controlled.
Marijuana under cultivation indoors where light, temperature and humidity are controlled. Yehyun Kim /

Legislators are dealing with an issue that they might not have imagined just a few years ago: The acceptable amount of mold in marijuana.

But for some patients who use medical marijuana, the question isn’t a novelty but a serious matter of health.

At the end of last year, the state Department of Consumer Protection proposed a change that would set the maximum amount of colony-forming mold and yeast units in medical marijuana at 100,000 per gram and would allow no traceable amounts of a breed of mold called Aspergillus that is known to cause a lung infection.

Previously, the state’s two labs were using different standards. The change would mean an increase in the allowable amount of mold and yeast for one lab and a decrease for the other.

Patients have said they’re worried that the new mold allowances will mean the product isn’t safe, and several asked that the total count be set at 10,000 units per gram.

The state Attorney General’s office approved DCP’s proposed change Tuesday, and the department submitted it to the Legislative Regulation Review Committee for final approval Wednesday.

The committee has 45 days to put it on its agenda.

“The purpose of this regulation is to update microbial testing standards for medical marijuana to better protect public health and safety,” the letter that DCP legal director Julianne Avallone sent to lawmakers read. “This proposed regulatory change will create clarity and consistency for medical marijuana laboratories and medical marijuana patients.”

The public comment period ended in February, and many patient-submitted comments asked that the limit be brought down to 10,000 units per gram.

“This is medicine, it should have strict standards and the companies producing it need to be held to those standards,” one comment read.

In 2020, the state approved a request from AltaSci, one of the state’s two labs that test cannabis, to increase the total limit to 1 million colony-forming units per gram with the additional Aspergillus testing.

The state approved the change via private email and did not alert patients, which sparked further concern about transparency in the program. The decision to officially change the limits came after patient outcry over the 2020 approval.

Northeast Laboratories left its limit at 10,000 colony-forming units. Several patient public comments requested that the standard remain at that level.

Lila McKinley, a DCP staff attorney, said department officials consulted with microbiologists in making the decision to leave the proposed limit at 100,000 colony-forming units. The decision was made because the state didn’t think commenters took all factors into account, including the Aspergillus testing requirement.

While some states have lower requirements, not all require Aspergillus testing. Some don’t have testing regulations, and others have requirements for specific testing outside of Aspergillus.

There’s no national policy on testing regulations because the substance is illegal federally.

Both of Connecticut’s laboratories have expressed support for the state’s proposed mold and yeast standards.

But Mike Esposito, a scientist at MCR Labs in Massachusetts, said that standard leaves room for materials that could be harmful both to patients and to employees who work with cannabis products.

For example, penicillium mold, which many people are allergic to, is often found on cannabis, he said. He also pointed to examples of farmers in other crops developing lung disease from mold exposure.

He’s heard many examples of people in the cannabis industry making standards around Aspergillus rather than other indicators or types of mold. He said he thinks Connecticut’s old standard for total count would be safer.

“I think that [Aspergillus-focused testing] really ignores a huge history of medical issues with yeast and mold,” Esposito said.

Lou Rinaldi, a Connecticut patient and advocate, shares Esposito’s safety concerns. He said Aspergillus is “far from the only safety consideration, particularly for immunocompromised patients.”

“Is Connecticut really comfortable with safety standards 10 times above the limits typically seen in regulated markets, including Massachusetts?” Rinaldi said.

The state also opted to change the required method of testing – from a plating method to a DNA-based method called qPCR. The new method is more specific and accurate, according to state documents.

Labs will have six months to implement the new testing methods if they’re approved, documents show.

Ginny is CT Mirror's children's issues and housing reporter and a Report for America corps member. She covers a variety of topics ranging from child welfare to affordable housing and zoning. Ginny grew up in Arkansas and graduated from the University of Arkansas' Lemke School of Journalism in 2017. She began her career at the Arkansas Democrat-Gazette where she covered housing, homelessness, and juvenile justice on the investigations team. Along the way Ginny was awarded a 2019 Data Fellowship through the Annenberg Center for Health Journalism at the University of Southern California. She moved to Connecticut in 2021.