Police want to make sure you know your source before you use recreational drugs.

The Ontario Association of Chiefs of Police is running the campaign as part of its annual crime prevention campaign. Director of Government Relations and Communications Joe Cuto says this year they’re focusing on street drug dangers and the timing for the legalization of marijuana sales lines up well with this opioid awareness strategy.

Cuto says illegally sold marijuana is extremely dangerous because it can come into contact with opioids. He says having a controlled legal market to buy this product in will definitely help cut down that risk to recreational drug users.

Medial officials say even small doses of opioids like fentanyl and carfentanil can be deadly. You can learn more about the Know Your Source campaign here.