Which material is commonly used in the construction of the outer shell of a structural firefighting protective coat?

The outer shell of a structural firefighting protective coat is commonly made from PBI (polybenzimidazole). This material is particularly valued in firefighting gear due to its excellent heat and flame resistance properties. PBI has a high resistance to thermal degradation and does not burn, melt, or drip when exposed to high temperatures, making it an ideal choice for protecting firefighters in hazardous environments.

Additionally, PBI materials maintain their protective characteristics even after repeated washings and exposure to extreme conditions, which helps ensure the longevity and reliability of the gear. Its lightweight nature also contributes to the comfort of the firefighter, allowing ease of movement while providing necessary protection.

Other materials, while used in various capacities within firefighting gear, do not provide the same level of thermal protection or durability as PBI for the outer shell of a firefighting coat.