Fentanyl is dangerous dangerous stuff. Not when correctly and carefully used - then it is a miracle of modern medicine. We carry it in the drug box on the ambulance, and use it when appropriate. (And it, and other such things in that box, are handled and accounted for with some fairly over-the-top inventory control procedures that rival those for nuclear launch keys...).
However, our first-responder nightmare comes from accidental exposure to the substance. We'd had extensive retraining this year because of incidents where responders overdosed from inadvertent contact with a patient's illicit substances. It's to the point where I carry a bag with a hazmat suit...
http://www.cnn.com/2017/06/08/health...ids/index.html
https://www.dea.gov/druginfo/Fentany...s_June2017.pdf