Treatment of cyanide exposure

The first aid for cyanide exposure USED to be amyl nitrite. This is the stuff the Army issues as a blood agent antidote - cyanide is a blood agent. Unfortunately for the civilian population, this stuff is a controlled substance because you can get really high on it. They have found that Vitamin B12a, of all things, is REALLY good at cleaning cyanide out of your system. It is therefore the preferred treatment for cyanide poisoning.