California’s first crop of cannabis was grown without safety regulations in place. As a result, the state’s inaugural batch of fully legal cannabis may have greater levels of pesticide, mold, or contaminants than cannabis grown in more strictly regulated states like Colorado or Oregon.

Earlier this spring, cannabis testing firm Steep Hill Laboratories investigated 44 samples of medical cannabis products from various dispensaries in California and discovered that 93 percent of them contained levels of pesticides that exceeded the safety limits set by other legal cannabis states.

Medical cannabis has been available in California since 1996, but state officials never imposed regulations on how medical cannabis products should be tested or what levels of potential contaminants should be permissible for public consumption.

“Buyer beware,” said Donald Land — University of California chemistry professor and chief scientific consultant for Steep Hill said. Land added that those buying weed in California “wrongly assume [cannabis products] have been tested for safety,” but “unfortunately, that’s not true.”

California is now implementing regulations for quality testing and contaminant levels. Growers and retailers have six months to sell off any products that was grown prior to the implementation of the new regulations, as long as they label them as untested.

“That’s one of the biggest reasons for regulation: to establish rules that protect public safety and improve the quality of the product,” said Alex Traverso, Bureau of Cannabis Control spokesman. “When people see a sticker that says ‘Not tested,’ at least they know and they can choose whether they want to purchase that or not.”