What exactly is a “nonflammable” refrigerant?

[coolguy4]

So I got bored yesterday, so I decided to do my own flammability test of R134A refrigerant. Yes I know about the dangerous fumes produced. What I did is I set up my butane torch to stay lit, and I sprayed a small amount of R134A vapor on the flame. I was expecting it to blow the flame out, but to my surprise, the stuff burned! It didn’t support combustion, but it burned pretty well when the torch was held to it. So how could that be “non flammable”? I did some research, and I found on a few MSDS sheets that it can burn, but only under certain conditions, like high oxygen concentration or pressures above atmospheric pressure.

So what exactly is the definition of a “non flammable” refrigerant? Does that just mean it won’t support combustion? And after seeing how well R134A burns even though classified as not flammable, it’s a bit scary to think about a “mildly flammable” refrigerant, like R1234YF. Not because I’m afraid of flammable refrigerants, but because it is labeled as “mildly flammable” when it is probably actually “highly flammable”.