IATA (International Air Transport Association) Dangerous goods regulations (43rd edition effective Januay 2002)...Section 2.3.4 'Goods acceptable with operator approval as baggage'.
184.108.40.206 - Non-flammable Gas cylinder fitted into a life jacket.
Not more than two small cylinders, containing carbon dioxide or other suitable gas in Division 2.2 per person fitted into a self-inflating life jacket for inflation purposes plus not more than two spare cartridges.
Bottom line - Check the airline involved as they have final say but they are approved for carriage as baggage unless the individual airline says no. Use the above reference when you call, as you undoubtedly will get some poor lad or lass who won't have a clue!
Well I wanted to take two of those from Helsinki to Mallorca, via Zuerich and Barcelona. Helsinki was ok, Zuerich was ok BUT in Barcelona a very unhelpful security guard refused to discuss the matter. I referred to the IATA regulations but her only comment was "not in Spain". I then asked for her senior officer but unfortunately she claimed to be the most senior on site, so I ended up leving the cartridges with her.
Not impressive. As I am sure you know the airlines themselves (mainly thru IATA) determine what DG's are
permitted for carriage; It isn't up to the security guard UNLESS the carrier involved had notified
them specifically but then she would surely have said. Odd.