This stuff is used in your air conditioning (certainly up to 2011) as well as a whole load of other refrigeration and air conditioning.
It seems our enterprising mates in southern China have started to make fake gas mixing R134a with methyl chloride and a load of other s**t.
There have been a few incidents with vehicles and a Greek bus but the majority are within the container industry reporting 4 dead. This stuff has been found in the Far East, Africa, Spain and the USA but reports suggest all markets are at risk. It is mainly in the disposable cylinders favoured by small garages and home repairers and sold through the internet or 'off the back of a lorry'.
Like fake Vodka and Wine the fake cylinders curently have spelling errors and dodgy lables but these SoB's will learn quick.
The fake gas will eat anything aluminium (the evaporator under your dash for example) it will then burst and fill the vehicle with a toxic mix that includes things like phosgene, hydrofluoric etc. It also has a habit of burning on contact with the air so that small leak will go 'nuclear' pretty quickly.
Everyone is trying to save money and these criminals are relying on internet purchases and back street sales. The only protection is to purchase direct from an authorised distributor or use workshops that do that.
A few links...
http://www2.dupont.com/Refrigerants/en_ ... 20125.html
http://www.containerownersassociation.o ... erants.pdf
http://abclocal.go.com/kgo/story?sectio ... id=8413677
Counterfeit R22 and R134a refrigerant puts engineers at risk says DuPont
http://english.vietnamnet.vn/en/busines ... osion.html
http://www.seattlepi.com/local/komo/art ... 249749.php
http://blogs.ft.com/beyond-brics/2011/1 ... z1qsfw9f5D
You been warned