Almost 20 percent of marijuana products in California have failed the state’s new safety-testing standards for contamination and labeling accuracy, the Associated Press reports.

While growers argue that the standards are too strict, costly, and inconsistent, some testing experts say the standards don’t go far enough to adequately catch fungal contamination that would otherwise be found in routine drug and food testing.

California now has the country’s largest legal market of marijuana products. Since testing regulations went into full swing there on July 1, labs have examined nearly 11,000 batches of products ranging from buds to oils and edibles. About 2,000 products failed the tests. Of those, about 65 percent of failures were down to labeling and potency issues. The concentration of the psychoactive cannabinoid tetrahydrocannabinol (THC) in any given product must be within 10 percent of what is listed on the label to pass the test, for instance.

The remaining failures were largely linked to unacceptable levels of pesticide residues and the presence of other impurities, such as bacteria and mold.

The California Growers Association, a marijuana industry group, has blown back on the standards, saying they’re too strict and require growers to stick to unreasonably narrow targets for labeling accuracy. The association also complained that the testing was costly, noting that small marijuana farms were getting hit with testing fees of up to $10,000. The California Cannabis Manufacturers Association, meanwhile, complained that lab results could be inaccurate, yet there was no mechanism to correct lab reports.

Lab testing companies still say the rules don’t go far enough for assessing contamination. The chief scientific officer for Santa Ana-based testing company Cannalysis, Swetha Kaul, told regulators last month that the testing rules miss mold and yeast contaminants that standard pharmaceutical and food testing would otherwise catch. Kaul said that the lab had seen cannabis products with mold clearly growing on them that still managed to pass the state’s testing requirements.

Kaul urged the state to “create a bigger net to catch things.”