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.

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.

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

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

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 seconds, and predictions of time-to-pain for up to 50 seconds. 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 insulation of materials used in protective clothing when exposed for a short period of time to a hot surface with a temperature up to 600°F (316°C).

1.2 This test method is applicable to materials used in the construction of protective clothing, including, but not limited to: woven fabrics, knit fabrics, battings, sheet structures, and material composites, intended for use as clothing for protection against exposure to hot surfaces.

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 and health practices and determine the applicability of regulatory limitations prior to use.