This is the stuff that's got the "Industry" nervous. particularly DuPont who have made a fortune out of having a monopoly on ozone depleting gases for over 50 years, hence the loads of misinformation about it.
http://archive.greenpeace.org/ozone/greenfreeze/
Over here of late, some service centres are converting to it, due to its positives. It doesn't accumulate in the atmosphere, is a drop in for all know refrigerants, (including R134a) hence conversions are much cheaper, it costs only a fraction of other gases (a 4.5 kg bottle will service approx 40 cars and costs A$155) and it gets colder than the others.
Normal LPG as used in a barbeque can be used in moderation, to flush out the system if required at any stage and its operating pressures are lower so it's easier both on the system and the car.
The frightener they use is that it is a derivative of Propane/Butane but I have seen on TV a tset that showed 134a will explode before this stuff will and in fact there's only 30 grams, about the amount in a cigarrette lighter of flammables in an average charge which is offset by other additives.
Latest trick here is for the gullible types who are protecting the multi nationals, to refuse to service any car that has it in it based on this fire risk falacy
and where they have "licenced" anybody supposedly handling 134a, which IMO is the reason the "Industry" is now full of cowboys, they have no reason to licence this stuff, so they threaten to prosecute anybody found putting it into any system because according to them, it means they have evacuated the system of the ozone depleting gases illegally, rather than try to find a false way of getting them licenced. If they licence this stuff, they'll need to licence anybody who owns a gas stove or barbeque.
I mentioned this on another forum as I have it in my 16V and it is by far the best the air/con has ever worked in that car, and I understand if you search around, there are places over there supplying and using it, so a good viable easy option for you to consider.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.