Since about the mid 1950s there has been an increasing demand for these environmentally acceptable gases to meet the rapidly increasing requirements in all industrialised countries, as well as in the economically advanced developing countries.
Phakathi ko 1950 kwabakho imfuneko emandla ngokwendawo ezamkela irhasi ukunxulumanisa olukhawulezileyo oluyimfuneko kulwando lwamazwe oshishino ngokunjalo kwezoqoqosho lwamazwe asele ekhulile.