This sub-class includes the manufacture of industrial gases. Units in this sub-class are primarily engaged in the manufacture of liquefied or compressed inorganic industrial or medical gases: elemental gases, liquid or compressed air, refrigerant gases, mixed industrial gases, inert gases such as carbon dioxide and/or isolating gases. This sub-class also includes: •carbon dioxide conditioning activities, which are usually part of carbon dioxide aggregation activities. •manufacture of industrial gases through a permanent supply network •manufacture of methane, not for the provision as a gaseous fuel through a permanent supply network