Last week, CBC reported that police in Ontario seized a substance described as an opioid-based drug that resembled cannabis. While the substance might have looked similar to ground up cannabis flower, police reported that it was in fact the dangerous opioid drug carfentanil.

Following the seizure of the drug, police have begun warning people to exercise caution when purchasing cannabis outside of the legal system. However, Cynthia Olsen of the Ontario Harm Reduction Network (OHRN) said cannabis consumers aren't likely to be fooled by the imitators. Most people should be able to tell the difference if they see the stuff up close.

"It actually had no resemblance to cannabis...by its weight, or by its scent, or by its texture," Olsen told CBC. "There was no indication that that substance was being marketed or sold as cannabis."

People shouldn't be too concerned about buying cannabis mixed with carfentanil or other opioids either, she said, as Canada has not seen a single documented case of cannabis being intentionally laced with opioids. And we probably won't see that happen in the near future. The high price of opioids and the relatively low cost of cannabis mean that "it makes no sense" financially for dealers to cut their marijuana with drugs like carfentanil.

"It's not being deliberately changed or laced or cut with fentanyl or carfentanil," Olsen said. "That, I think, is some of the important messaging."

However, Olsen does say there is a possibility that illicit cannabis may be unintentionally cross-contaminated with opioids—though not likely to dangerous levels. Still, she advises cannabis consumers look to legal retailers to ensure they're getting the safest product possible.