What is a firestop collar used for?

A firestop collar is specifically designed to protect plastic pipes from fire. When a fire occurs, these collars expand and create a barrier that helps prevent flames and smoke from passing through wall and floor openings where the pipes are installed. This function is crucial because plastic pipes can melt and create openings that allow fire and smoke to spread.

The correct answer highlights the primary role of a firestop collar as a protective measure in maintaining the integrity of fire-rated assemblies. While other options mention potential applications related to fire safety, such as sealing conduits or preventing water damage, they do not accurately capture the specific purpose and functionality of a firestop collar in relation to protecting plastic piping systems in buildings.