A/C Charge by Myself
Well even traditional refrigerants are "flammable" because they have oil aspirated throughout the system. And the older refrigerants, ammonia, methyl chloride, and sulfur dioxide were certainly not "human friendly." LOL
All the traditional Dupont refrigerants, R11/12/22/500/502 etc, produce deadly phosgene gas when run through a flame, so they are not exactly inert.