"Explosion" doesn't have to involve combustion. I agree the reporting was poor. Only a low pressure refrigerant would be able to exist in an open container (per the article) for any appreciable length of time in September. As far as I know, all flammable refrigerants are high pressure. Perhaps "open" means unsealed, or the seal is broken. Hard to tell from such shoddy reporting. More people would realize how bad the news reporting is these days if they knew anything about the things being reported.
One thing that comes to mind is that some of the drop in refrigerants for 22 are propane based...possible source of combustion.
Works great..I figure by the time the evaporator goes in a house fire you are already done anyway.
Personal usage only ! You dont want to fill someone elses unit with propane whether legal or not for the local IMO