In fire protection terminology, what does the term "intumescent" refer to?

The term "intumescent" specifically refers to a type of firestop material that expands when exposed to heat. Upon reaching high temperatures, typically during a fire, intumescent materials undergo a chemical reaction that causes them to swell significantly, resulting in a protective char. This expansion helps to seal gaps and prevent the spread of fire and smoke, thereby playing a crucial role in fire safety and protection in buildings.

Intumescent materials are commonly used in various applications, such as sealing penetrations and joints in fire-rated walls and floors, and they are an essential component of many fire protection systems. This characteristic makes them integral to maintaining the integrity of fire-resistive assemblies and ensuring compliance with fire safety codes.