Buyers of illicit cannabis are getting both less than they paid for and more than they bargained for, according to the Ontario Provincial Police.

Most of the samples didn’t have a THC level claimed on the label but half a dozen purporting to have more than 90 per cent THC actually contained 45 to 60 per cent.

“High levels” of pesticides were detected in all the samples, the OPP said, with myclobutanil the most common, ranging from 0.3 parts-per-million (ppm) to over 500 ppm, which is several thousand times higher than Health Canada’s detection limits.

When heated, myclobutanil can generate hydrogen cyanide when heated, the OPP said. The toxic compound is linked to cardiovascular, respiratory and neurological effects.

Myclobutanil was also found in several dried cannabis samples seized by the OPP, again at concentrations greater than the Health Canada limit.

The pesticides used in illicit cannabis production also pose an environmental risk, the OPP said, noting that police team up with the Ministry of the Environment, Conservation and Parks on tackling illicit cannabis production operations.

During one takedown a year ago, ministry officials and police found large open holding tanks filled with liquid fertilizer connected to a storm water pond discharging into a municipal drain. Several hazardous pesticides that require special management were also identified at the site.

The OPP-led provincial joint forces cannabis enforcement team aims to take down illegal storefronts, cannabis grow operations and online illicit cannabis sites.

“We will continue work with our various partners to expose the health and public safety risks related to the illegal market,” said Rachel Huggins, deputy director of the OPP and the executive lead on cannabis legislation.

“The test results are clear evidence that consumers don’t know what they’re getting when they purchase illegal cannabis products and how important it is to know the facts.”