This part of ISO 22734 defines the construction, safety and performance requirements of packaged hydrogen gas generation appliances, herein referred to as hydrogen generators, using electrochemical reactions to electrolyse water to produce hydrogen. This part of ISO 22734 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). This part of ISO 22734 is applicable to hydrogen generators intended for indoor and outdoor residential use in sheltered areas, such as car-ports, garages, utility rooms and similar areas of a residence. This part of ISO 22734 includes cord-connected equipment for outdoor and garage use only. Portable generators as well as hydrogen generators that can also be used to generate electricity, such as reversible fuel cells, are excluded from the scope of this part of ISO 22734. Hydrogen generators that also supply oxygen as a product are excluded from the scope of this part of ISO 22734. This part of ISO 22734 is intended to be used for certification purposes.