Standard Test Method for Measuring the Transmitted and Stored Energy of Firefighter Protective Clothing Systems

Importancia y uso:

5.1 Firefighters are routinely exposed to radiant heat in the course of their fireground activities. In some cases, firefighters have reported burn injuries under clothing where there is no evidence of damage to the exterior or interior layers of the firefighter protective clothing.5 Low levels of transmitted radiant energy alone, or a combination of the transmitted radiant energy and stored energy released through compression, can be sufficient to cause these types of injuries. This test method was designed to measure both the transmitted and stored energy in firefighter protective clothing material systems under a specific set of laboratory exposure conditions.

5.2 The intensity of radiant heat exposure used in this test method was chosen to be an approximate midpoint representative of ordinary fireground conditions as defined for structural firefighting (1, 2).6 The specific radiant heat exposure was selected at 8.5 ± 0.5 kW/m² (0.20 ± 0.012 cal/cm²-s), since this level of radiant heat can be maintained by the test equipment and produces little or no damage to most NFPA 1971-compliant protective clothing systems.

5.2.1 Utech (2) defined ordinary fireground conditions as having air temperatures ranging from 60 to 300 °C and having heat flux values ranging from 2.1 to 21.0 kW/m² (0.05 to 0.5 cal/cm²-s).

5.3 Protective clothing systems include the materials used in the composite structure. These include the outer shell, moisture barrier, and thermal barrier. It is possible that they will also include other materials used on firefighter protective clothing such as reinforcement layers, seams, pockets, flaps, hook and loop, straps, or reflective trim.

5.4 The transmission and storage of heat energy in firefighter protective clothing is affected by several factors. These include the effects of wear and use conditions of the protective clothing system. In this test method, conditioning procedures are provided for the laundering of composite samples prior to testing, and also composite sample moisture preconditioning. The amount of moisture added during preconditioning typically falls into a worst-case amount in terms of predicted heat transfer, as suggested by Barker (3).

5.5 Two different procedures for conducting the test are provided in this test method. Procedure A measures only the transmitted energy that passes through the composite, without compression, during the exposure time. In this approach, the length of the radiant exposure is likely to be sufficient in the prediction of a second-degree burn injury. Procedure B involves using a fixed radiant heat exposure time to determine if a second-degree burn injury will or will not be predicted. If a second-degree burn injury is predicted, the time to a second-degree burn injury is reported. If a second-degree burn injury is not predicted, the result is indicated as “no predicted burn.” This procedure includes recommended fixed radiant exposure times.

Subcomité:

F23.80

Volúmen:

11.03

Número ICS:

13.340.10 (Protective clothing)

Palabras clave:

firefighters; material systems; protective clothing; radiant heat; second-degree burn injury; stored energy; transmitted energy;