Although the EPA found that use of this refrigerant would contribute to virtually zero damage to the earth's ozone layer, it has scheduled R-123 for phaseout in 2015.
I think it was back in 1990 that I first heard of this refrigerant. I had attended a conference sponsored by the Environmental Protection Agency in Baltimore and R-123 was mentioned as a possible replacement for the soon-to-be-banned CFC, R-11.