Fire in a Room

In a in ar rooma fire's transition between true m a series of very, a well known states. So you start with a small fire that then the heat that's derived from it then starts to heat up materials around and they start to gas off. It comes to a point where everything becomes so heated up that it's evolving all its these thermal decomposition products toll a fire burning away. But i'm not sure that you could have fire in absolutely zero oxygen. Or what's the minimum oxygen level? Say it's in a well, in a room. Amso you can have fires and zero gravity, and fires and zero gravities don't look like the kind of flames we