This International Standard specifies requirements for suction catheters, including closed suction catheters, made of flexible materials and intended for use in suctioning of the respiratory tract. Angled-tip suction catheters (e.g. Coudé catheters) and suction catheters with aspirator collectors are not considered to be specialized and are therefore included in the scope of this International Standard. Suction catheters intended for use with flammable anaesthetic gases or agents, lasers or electrosurgical equipment are not covered by this International Standard. NOTE See ISO/TR 11991 for guidance on airway management during laser surgery of the upper airway.