This document specifies minimum performance and safety requirements for air entrainment devices used for delivery of designated oxygen concentrations to patients and includes a test method to check the accuracy of the oxygen concentration in the air/oxygen mixture generated by the air entrainment devices. Air entrainment devices can be a fixed to deliver a single oxygen concentration or adjustable, to deliver a range of oxygen concentration outputs. It also specifies marking requirements and recommends an optional system of colour coding to assist the user in identifying the designated oxygen concentration. This document does not cover air entrainment devices which are integral with medical devices specified in other standards e.g. emergency lung ventilators, humidifiers, nebulizers, etc.