ISO 22734-1:2008 defines the construction, safety and performance requirements of packaged or factory matched hydrogen gas generation appliances, herein referred to as hydrogen generators, using electrochemical reactions to electrolyse water to produce hydrogen and oxygen gas.It is applicable to hydrogen generators that use the following types of ion transport medium:Group of aqueous bases;Solid polymeric materials with acidic function group additions such as acid proton exchange membrane (PEM).ISO 22734-1:2008 is applicable to hydrogen generators intended for indoor and outdoor commercial and industrial use (non-residential use). Hydrogen generators that can also be used to generate electricity such as reversible fuel cells are excluded from the scope of this International Standard.ISO 22734-1:2008 is intended to be used for certification purposes.