This standard specifies the dimensions and the allocation of noninterchangeable screw-threaded (NIST) connectors intended to be used with medical gases. Medical gases are for example provided in gas cylinders or produced on site. They are supplied to the patient via interconnected devices (such as pressure regulators, hose assemblies, lung ventilators, anaesthetic workstations). At each interface gas-specific connectors are needed to ensure that the intended medical gas is administered to the patient. The specifications given in this standard are based on DIN EN 15908:2011-01 "Anaesthetic and respiratory equipment - Non-interchangeable screw-threaded (NIST) low-pressure connectors for medical gases", German version EN 15908:2010, which has been adopted as an International Standard. The standard has been prepared by CEN/TC 215 "Respiratory and anaesthetic equipment" (secretariat: BSI, United Kingdom) in collaboration with ISO/TC 121/SC 1 "Breathing attachments and anaesthetic machines" (secretariat: DIN, Germany) under participation of German experts. The responsible committee at DIN is Working Committee NA 053-03-06 AA "Zentrale Gasversorgungsanlagen" ("Central gas supply systems") of the Rescue Services and Hospital Standards Committee (NARK).