DuPont™ Nomex® and the Thermo-Man® Test
In industrial applications, the main thermal hazards against which workers need to be protected are heat and flame, fire, heat of an electric arc and molten metal splashes.
DuPont™ Thermo-Man® was invented by DuPont and has been a basis for the development of test method standard ISO 13506.
Thermo-Man® is a life-size mannequin equipped with 122 heat sensors, which is dressed in test garments and then totally engulfed into flames generated by propane gas burners.
This test simulates the exposure of a garment to a typical excess fuel fire with temperatures rising up to 1,000°C. It predicts the garment’s protective performance and integrity against heat, flame and fire during such a typical fire incident.
The heat sensors record the temperature rise on the surface of the mannequin while a computer simulation programme calculates:
- The predicted percentage of second- and third-degree burns a person might suffer on his or her body under similar conditions
- The position of the burns, and the percentage of burns compared to the total of the body
- The burn evolution over the measuring time, resulting in the person’s chance to survive the incident (in %) in conjunction with the victim’s age
EN ISO 11612 stipulates an optional test for the whole garment according to ISO 13506 at 84kW/m2 (2cal/cm2/sec.) and recommends 4 seconds flash fire exposure time for the following reason:
“Experience has shown that test conditions of at least 4 seconds at 84 kW/m2 give the most complete information about the protective performance of single and multilayer clothing assemblies. For multilayer garments or for clothing assemblies, test conditions of up to 8 seconds might be necessary.” (source: EN ISO 11612)
Garments made of Nomex® were compared to cotton and cotton-blend garments which had been treated with flame-retardant chemicals:
- Wearing protective clothing made of Nomex® results in the lowest percentage of total body burns, increasing the survival chances of a heat and flame victim considerably.
- The consequences of the flash fire exposure after the 4 seconds’ Thermo-Man® test on the FR cotton blends are devastating compared to those on garments made of Nomex®.