California’s Department of Cannabis Control shut down the testing of cannabis legal products at the majority of its testing labs Jan. 1, due to concerns over labeling scams.

The department shut down the state-certified cannabis testing labs over allegations the labs are artificially increasing the amount of THC in products to raise their market value.

State law requires that all legal cannabis products be tested at state-certified labs for contaminants like pesticides as well as for potency of THC—the main psychoactive compound in cannabis.

Products containing cannabis must display the THC potency as a percentage. On the cannabis market, the higher the THC, the higher the monetary value.

To combat fraud, the department has new testing standards for testing dried cannabis flower—the smokeable form of the drug—including bud and non-infused pre-rolls, according to the department’s webpage.

Labs that don’t meet such standards can still test other cannabis products like edibles and vape pens—but until they meet the new requirements, they will be blocked from testing the dried flower, the most popular version of the drug.

As of Jan. 4, only 13 of the 38 certified testing labs meet the new requirements, according to the department’s webpage.

The new regulations are a result of Senate Bill 544, a law passed by California’s state legislature in 2021, which raised the cannabis testing standards.