Dealers don't clean their scales. That's why it shows up in other drugs that are or were powders. That's it. Fentanyl and carfentanyl are just that lethal. Those benzos and other pills begin as powder before being pressed. Also, pretty much all black market oxys or Percocets are pressed fent these days from what I've heard. Unfortunately, it takes very little fentanyl to cause an overdose, especially in those who don't have any previous history with opioids (i.e. kids taking mdma at a music festival not expecting to stop breathing) . Cannabis laced with fentanyl is nonsense.