This clause of Part 1 is replaced by the following. The following extraction systems are covered as well: back draft ventilation systems; downdraft ventilation systems; fume extraction modules. This International Standard deals with the safety of electrically operated commercial hoods intended for installation above commercial cooking appliances such as ranges, griddles, griddle grills and deep fat fryers, and not intended for household and similar use, their rated voltage being not more than 250 V for single phase hoods connected between one phase and neutral, and 480 V for other hoods. Only single complete units and hoods supplied as separate parts which when assembled form a complete working hood, incorporating a fan, are within the scope of the standard. NOTE 101 Hoods are used, for example in kitchens of restaurants, canteens, hospitals and in commercial enterprises such as bakeries, butcheries, etc. The hood may be used above one or more appliance of the same or different types. So far as is practicable, this standard deals with the common hazards presented by these types of appliances. NOTE 102 Attention is drawn to the fact that; for hoods intended to be used in vehicles or on board ships or aircraft, additional requirements may be necessary; in many countries additional requirements including ventilation requirements are specified by the national health authorities, the national authorities responsible for the protection of labour and similar authorities; for hoods incorporating a filter system with means for ionizing the air, IEC 60335-2-65 also applies. NOTE 103 This standard does not apply to; domestic range hoods (IEC 60335-2-31); purpose-built hoods, although this standard can be used as a guide (a purpose-built hood is either constructed on-site or specially constructed in the factory and is not mass produced); hoods not incorporating a fan; hoods designed exclusively for industrial purposes; hoods intended to be used in locations where special conditions prevail, such as the presence of a corrosive or explosive atmosphere (dust, vapour or gas). NOTE 104 Requirements for hoods with externally mounted fans are under consideration.