Thermal Protective Performance Testing
topic
TPP testing exposes fabric specimens to combined radiant and convective heat flux at 84 kilowatts per square metre per ASTM F1939 and ISO 17492, measuring heat transmitted through the specimen to copper calorimeters or skin simulant sensors, calculating the time to second-degree burn prediction and the TPP value expressed as the product of incident heat flux and time to pain threshold in calories per square centimetre, with minimum TPP values of 35 cal per square centimetre specified for structural firefighting clothing.
Role
Provides the primary standardised laboratory measurement enabling objective comparison of clothing thermal protection against specification requirements, with TPP being the single most important performance descriptor for structural firefighting clothing that appears in all major standards and guides material selection and composite construction optimisation for maximum protection at minimum weight and bulk.