Mike Erickson wheels his power chair around a Toronto supervised consumption site, waiting for his friend to show up.

He has tested his fentanyl there and the results showed it did not have any of the "garbage" — animal tranquillizer or benzodiazepines — that is increasingly mixed with the deadly opioid sold in the city.

He skipped testing his drugs one day about a month ago and some of that garbage nearly killed him.

He remembers injecting what he thought was pure fentanyl into a vein and immedia…