Firestopping seals and protects openings and joints in fire rated wall, floor and ceiling assemblies.  It is a term used in the construction industry that includes several different components.  These components make up what is known as a Passive Fire Protection (PFP) system.  PFP are one of three systems that make up building fire safety;  Active Fire Protection (AFP) and Fire Prevention are the other two systems.  When there is an unprotected opening in a fire rated wall, floor, and/or ceiling assembly, the PFP system becomes compromised, allowing smoke, poisonous gases and fire to spread.  Due to the fact that any number of building materials can penetrate a fire rated assembly, including electrical, telecommunications, mechanical, plumbing and structural elements, there are a variety of firestopping materials specifically designed for each application.