5.1 This test method rates materials intended for use as protective clothing against exposure to hot surfaces for their thermal insulating properties and their reaction to the test conditions.

5.2 The thermal protection time, as determined by this test method, relates to the actual end-use performance only to the degree that the end-use exposure is identical to the exposure used in this test method; that is, the hot surface test temperature is the same as the actual end-use temperature and the test pressure is the same as the end-use pressure.

5.2.1 Higher pressures beyond the 3-kPa (0.5-psi) pressure provided by the calorimeter assembly in this test method shall be permitted to be used in this test method to simulate the conditions of protective clothing use.

5.3 The procedure maintains the specimen in a static, horizontal position under a standard pressure and does not involve movement.

5.4 One of the intended applications for this test method is comparing the relative performance of different materials.

5.5 This test method is limited to short exposure because the model used to predict burn injury is limited to predictions of time-to-burn for up to 30 s, and predictions of time-to-pain for up to 50 s. The use of this test method for longer hot surface exposures requires a different model for determining burn injury or a different basis for reporting test results.

1.1 This test method is used to measure the thermal-protective properties of materials that provide thermal insulation when contact is made with hot surfaces during a limited exposure up to 1 min.

1.1.1 During this limited time exposure, the temperature can reach a threshold approaching 600 °F (316 °C).

1.2 Because there is significant potential for injury, the thermal-insulative properties of the materials used in the construction of protective clothing including, but not limited to, woven fabrics, knit fabrics, battings, sheet structures, and any composites, need to demonstrate they are capable of reaching a heat threshold that is sufficient to allow prediction of either a pain sensation or a second-degree burn injury to human tissue.

1.3 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat under controlled laboratory conditions and should not be used to describe or appraise the thermal hazard or fire risk of materials, products, or assemblies under actual exposure conditions.

1.4 The values as stated in SI units are to be regarded as the standard. The values in parentheses are given for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.