Take a few minutes to find and read through the safety warnings for using compressed oxygen especially, and a cutting torch as well. The thing that sticks in my mind, looking at a nice set of older regulators, is the advice to always back the pressure out on the regulator, then crack the valve open very slowly, and with the regulator facing away from you and your face facing away from the regulator. Before that, crack the oxygen valve to blow any dirt out. Reduce the chances of the oxygen regulator blowing up in your face. Then there are a whole nuther set of warnings for once you get the torch started and how not to blow yourself up doing it. Most guys don't back out the regulator pressure, but at least look away when you open.