IEC 60335-2-40:2018 deals with the safety of electric heat pumps, including sanitary hot water heat pumps, air conditioners, and dehumidifiers incorporating motor-compressors and hydronic fan coils units, their maximum rated voltages being not more than 250 V for single phase appliances and 600 V for all other appliances. Partial units are within the scope of this International Standard. Appliances not intended for normal household use but which nevertheless may be a source of danger to the public, such as appliances intended to be used by laymen in shops, in light industry and on farms, are within the scope of this standard. The appliances referenced above may consist of one or more factory-made assemblies. If provided in more than one assembly, the separate assemblies are to be used together, and the requirements are based on the use of matched assemblies. This standard does not take into account refrigerants other than group A1, A2L, A2 and A3 as defined by ISO 817 classification, A2L refrigerants are limited to those of a molar mass of more than or equal to 42 kg/kmol based on WCF ? Worst Case Formulation as specified in ISO 817. This standard specifies particular requirements for the use of flammable refrigerants. Unless specifications are covered by this standard, including the annexes, requirements for refrigerating safety are covered by ISO 5149. Supplementary heaters, or a provision for their separate installation, are within the scope of this standard, but only heaters which are designed as a part of the appliance package, the controls being incorporated in the appliance. For appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be necessary; for appliances subjected to pressure, additional requirements may be necessary; This standard does not apply to: humidifiers intended for use with heating and cooling equipment (IEC 60335-2-88); appliances designed exclusively for industrial processing or appliances intended to be used in locations where special conditions prevail, such as the presence of a corrosive or explosive atmosphere (dust, vapour or gas). This sixth edition cancels and replaces the fifth edition published in 2013 and its Amendment 1:2016. This edition constitutes a technical revision.