This document specifies requirements for the basic safety and essential performance of an oxygen concentrator in combination with its accessories, hereafter referred to as ME equipment, intended to increase the oxygen concentration of gas intended to be delivered to a single patient. Such oxygen concentrators are typically intended for use in the home healthcare environment by a single patient in various environments including any private and public transportation as well as in commercial aircraft.NOTE 1 Such oxygen concentrators can also be used in professional healthcare facilities.This document is applicable to a transit-operable and non-transit-operable oxygen concentrator. This document is applicable to an oxygen concentrator integrated into or used with other medical devices, ME equipment or ME systems.EXAMPLE 1 An oxygen concentrator with integrated oxygen conserving equipment function or humidifier function.EXAMPLE 2 An oxygen concentrator used with a flowmeter stand.EXAMPLE 3 An oxygen concentrator as part of an anaesthetic system for use in areas with limited logistical supplies of electricity and anaesthetic gases[2].EXAMPLE 4 An oxygen concentrator with an integrated liquid reservoir function or gas cylinder filling system function.This document is also applicable to those accessories intended by their manufacturer to be connected to an oxygen concentrator, where the characteristics of those accessories can affect the basic safety or essential performance of the oxygen concentrator. NOTE 2 Such accessories can include, but are not limited to, masks, cannulae, extension tubing, humidifiers, carts, carrying cases, external power sources and oxygen conserving equipment.This document does not specify requirements for oxygen concentrators for use with a medical gas pipeline system.If a clause or subclause is specifically intended to be applicable to ME equipment only, or to ME systems only, the title and content of that clause or subclause will say so. If that is not the case, the clause or subclause applies both to ME equipment and to ME systems, as relevant.Hazards inherent in the intended physiological function of ME equipment or ME systems within the scope of this document are not covered by specific requirements in this document except in 7.2.13 and 8.4.1 of the general standard.NOTE 3 See also 4.2 of the general standard.