Hi Trev,

You are GOOD!

You wrote my post for me just exactly the way I think I would have.
R-1234YF (Yell Fire) was apparently approved by the EPA before Mercedes told them about the flammability issue. I don’t know if that has been resolved either?

Only thing I can add is that the old R-12 would produce Mustard gas when burnt through the original, sniffing, propane leak detectors. It used a copper plate, stuck out in the tiny flame. The burning gases would combine and turn to a yellowish green colored flame in a slotted cylinder. The slot was the window to see into as the burning gases exited.
A whiff of that stuff and you knew that it was not good. I was told,
If you kept persistent at it, you would vomit!
I think Mustard gas was used in WW One as a disabling agent by the Germans or both sides for all I know.
That was a little before my time! ):-)

Phil
PS.
I write a lot in NOTES before posting over time but that doesn’t exclude me from being a maniac.