California's legal weed is going to have a huge pesticide problem

State rules could leave California’s first batch of recreational marijuana riddled with unknown amounts of pesticides, threatening the launch of the state’s projected $5 billion legal pot market on January 1.

State officials are racing to craft new legal weed policies, covering everything from licensing to banking to delivery drones, which don’t even exist yet. But pesticides are getting a pass, the Associated Press reports — at least for the first six months.

Under the state’s rules, growers and sellers, including the more than 1,300 legal medical dispensaries already operating in the state, have six months to sell their existing inventories before they have to start testing their stock for pesticides. It will be a year before stricter standards kick in, but any pot harvested after Jan. 1 still has to be tested.

That has some experts advising caution about the first wave of sales, which usually attract droves of first-time consumers.

“Buyer beware,” Donald Land, a chemistry professor at the University of California, Davis,, told the AP.

Land, who advises Steep Hill Labs, a company that analyzes legal marijuana samples in several states, warned that consumers shouldn’t expect their weed on the shelves to be safe just because it’s now legal.

All untested weed will be labeled as such, according to the California Bureau of Cannabis Control. In the meantime, according to Land, under California’s more lax medical regulations, less than five percent of the state’s medical inventory has been tested for pesticides and other contaminants, which can include powerful fungicides and rodent-killers that haven’t been tested for their health effects when smoked and inhaled.

Much of that tainted product could end up on store shelves, as businesses race to take advantage of the regulatory grace period before the mandatory testing kicks in.

This isn’t the first time California's consumers have been warned about pesticide-laced pot. A Steep Hill study of the state’s grass in September found that 86 percent of plants were contaminated with pesticide residue.