This part of ISO 11990 specifies a method of testing the continuous wave (cw) resistance of the cuff regions of tracheal tubes designed to resist ignition by a laser. Other components of the system, such as the inflation system and shaft (as defined in ISO 11990-1), are outside the scope of this part of ISO 11990. NOTE 1 The method for testing the laser resistance of the tracheal tube shaft is in the scope of ISO 11990-1. The specified test method 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, products or assemblies under actual clinical use conditions. However, the results of this test method may be used as an element of a fire risk assessment which takes into account all of the factors that are pertinent to an assessment of the hazard of a particular end use. NOTE 2 Caution should be observed in interpreting these results, since the direct applicability of the results of this test method to the clinical situation has not been fully established. NOTE 3 This test method might involve hazardous materials, operations and equipment. This part of ISO 11990 provides advice on minimizing some of the risks associated with its use but does not purport to address all such risks. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.