>> reporter: to doething wish td do, analyze the vapor produced by illicit thc oil they tested seven thc cartridges from licensed dispensaries and six from the black market. >> the illicit card has dangerous sin they the particulars and carbon monoxide and cyanide. >> reporter: that's right, cyanide. not one of them was safe for consumption? fair >> that's very fair to say every single one of them had something, some of them had a cocktail of things that were wrong with them. >> reporter: two of the illicit cartridges were counterfeit products seen here next to their legitimate counterparts. how bad were these these knockoffs? >> they had significant levels they had formaldehyde. >> reporter: the kingpin had cyanide.