There are growing suggestions that many samples of street drugs, including heroin, cocaine, MDMA and others are frequently contaminated with fentanyl – a potent opioid that can cause death rapidly when inadvertently ingested. Fentanyl is now implicated as a rapidly growing cause of deaths amongst illicit drug  users. Testing at one safe injection facility in Vancouver revealed that during one month in 2016 86% of samples tested were positive for fentanyl, whether pills or powder. A harm-reduction approach that appears to be gaining traction in North America is the use of test-strips to identify contamination – read more at the website of the Harm Reduction Coalition.