I've used much R12 from Mexico. It's actually manufactured by DuPont in Mexico and it works the same. And I smell no funny gasses or contaminants. So it you can get it, go for it. The last time I was there, a few months ago, they sell small cans, large cans, and 30 lb tanks. If only I could smuggle it back on the cruise ship I was on. Did I mention they are manufactured and labeled by DuPont?
Most all R12 substitutes sold these days are a cocktail consisting of mostly propane. These companies just camouflage their mix by calling it a hydrocarbon replacement. Hello - that's what propane and isobutane is. I use a $2 tank of torch propane mixed with 20% isobutane (camping fuel) in my ac systems, and it works absolutely *****in. In my truck, it was practically blowing ice cubes.
