This part of ISO 11990 specifies a method of testing the continuous wave (cw) resistance of the shaft of a tracheal tube designed to resist ignition by a laser. It is not applicable to other components of the system, such as the inflation system and cuff, which are defined in ISO 11990-2 (see Note 1).NOTE 1 ISO 11990-2 specifies the method for testing the laser resistance of the tracheal tube cuff.This part of ISO 11990 can be used to measure and describe the properties of materials, products or assemblies in response to heat and flame under controlled laboratory conditions. It does not describe or appraise the fire hazard or fire risk of materials, product