What does the annular space refer to in firestopping?

The annular space refers specifically to the distance between a penetrant, such as a pipe or cable, and the opening in a wall or floor through which it passes. This space is critical in firestopping because it can allow the passage of smoke, heat, and flames if not properly sealed. When firestopping materials are installed, they must fill this annular space effectively to ensure that the structural integrity and fire-resistance of the barrier are maintained. The correct selection highlights the importance of addressing this gap to enhance fire safety and comply with building codes. Other definitions provided do not accurately capture the specific relationship between the penetrant and the opening, which is central to understanding the functionality of firestopping measures.