Police in Stratford, Ont. are concerned about a drug called ‘shatter,’ a form of concentrated marijuana extract that was recently recovered in a drug bust in the small southwestern Ontario community.

According to police, shatter is made by extracting the high-inducing tetrahydrocannabinol chemical from marijuana plants, then purifying it through a chemical process involving butane fuel.

The result is a caramel-like substance with 70 to 80 per cent THC levels, much higher than the five- to eight-per cent THC content in a marijuana cigarette.

“You don’t need a lot of quantity to get high on this drug,” Insp. Sam Theocharis told CTV Kitchener.

Stratford police are now on the lookout for the drug after two men were arrested for possession earlier this week. The two suspects in their 40s have been charged with possession for the purpose of trafficking.

Police are moving to educate parents and students in the area about the dangers of the drug, which sells for about $100 a gram on the street.

Online instructions for making shatter warn that the butane fuel involved can create explosions or fires.

With files from CTV Kitchener