Is there a new type of freon that is compatible with an old R-12 system?

Nothing new since 2010 from what I can find in google.

my understanding is what someone said to me
old freon harmful to health
new freon is ok…
as he was replacing some freon
in an older machine.

Old Freon (R-12) was really bad for the ozone layer. New Freon (R-134a) is not as bad. Both are non-poisonous so won’t kill you right away, but there is asphyxiation danger if they displace enough air. There might be problems if you breathe low concentrations long term, but I would want to review current studies to verify.

As a former auto tech, I am familiar with the dangers R-12 poses to the ozone layer. However, I have an 1991 vehicle that has a R-12 system and may need topping off with Freon. I had heard that there was a new Freon type that was compatible for this purpose.

As part of the R-12 production ban, systems with R-12 had to get disposed of at certified facilities where it got is sucked out and filtered. The idea was to make R-12 available for still-running systems that could only use R-12, despite the stoppage of production. If you are resourceful, you can find some to top off your system.