Don’t Convert to R134a

As have I. Including carbon tetrachloride for several years. I'm surprised my hands haven't rotted off.
If I remember correctly, carbon tetrachloride was used for fire extinguishers decades ago. My neighbor bought one at an antique shop about 5 years ago. A sealed glass ball mostly full on liquid. The idea was to toss it at the base of the fire to break the glass and then get out real fast as the gas given off is highly toxic.