As Los Angeles moves toward allowing the sale of recreational marijuana, joining cities across the state in the newly legal enterprise, the Los Angeles Police Department offered a stern word of caution.

Yes, recreational pot will be legal to sell (and buy, and consume, and cultivate). But there are limits. And the LAPD will help enforce them.

“Let me be clear,” Assistant Chief Michel Moore said Tuesday. “The use of marijuana needs to be done in a responsible manner that’s consistent with the law.”

Moore’s comments came a day after the sale of recreational marijuana became legal in California, a voter-approved endeavor that has presented challenges for police and city leaders across the state as they decide how to handle the hotly anticipated retail sector.

What isn’t allowed? Driving under the influence of marijuana. Consuming pot in public. Purchasing or consuming recreational cannabis by someone under the age of 21, the Los Angeles Times reports.

The LAPD is working to educate officers through written bulletins and during roll-call meetings. The department is also working with the county’s Health Department and other agencies to determine the “intended and unintended consequences” the legal use of recreational marijuana might have on public safety, Moore said.