This part of this European Standard specifies requirements for ventilators, driven by a power source and intended for emergency and transport use. This covers a range of devices, from relatively simple ventilators intended, primarily, for use with a face mask and for limited periods (e.g. gas powered ventilators) through to devices for pre-planned longer term use. This includes gas-powered resuscitators, which are generally used by first responders.This part does not cover operator-powered ventilators (i.e. manual resuscitators). Ventilators aboard aircraft are likely to be subject to additional requirements and national/international regulations. Additional parts, e.g. concerning lung ventilators for critical care (see EN 794-1), home care ventilators (see EN 794-2), operator powered resuscitators and recent developments such as jet and very high frequency ventilation and oscillation are published or under consideration.