This document is applicable to the basic safety and essential performance of a nebulizing system, hereafter referred to as ME equipment or ME system, intended to alleviate the symptoms of patients by delivering an inhalational therapy to the respiratory tract of the patient. A Nebulizing system is intended for use in the home healthcare environment by lay operators as well as in professional healthcare facilities. This document includes: – nebulizing systems which can be powered by gas, (e.g., compressors, pipeline systems, cylinders); – electrically powered nebulizing systems [e.g., spinning disc, ultrasonic, vibrating mesh (active and passive), and capillary devices]; and – manually powered nebulizing systems. This document includes nebulizing systems used during spontaneous breathing (e.g., handheld equipment applied via a mouthpiece) as well as systems which are included into a ventilatory breathing system of a ventilatory support equipment or ventilators for ventilator dependent patients. This document includes nebulizing systems intended for use with adults, children, neonates and premature born. This document includes nebulizing systems intended for the supply of drugs within ventilatory breathing systems. This document does not apply to drug-specific nebulizers or their components (e.g., metered dose inhalers, metered liquid inhalers, dry powder inhalers). This document does not specify the requirements for respiratory humidifiers, the requirements for which are given in ISO 80601-2-74. This document is also applicable to those accessories intended by their manufacturer to be connected to nebulizing systems, where the characteristics of those accessories can affect the basic safety or essential performance of the nebulizing systems. 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.