The purpose of plumbing traps is to:

Plumbing traps are specifically designed to control odors in drainage systems. They achieve this by holding a small amount of water, which creates a barrier between the sewer gases present in the drainage system and the living spaces within a building. This water seal prevents unpleasant and potentially harmful gases from escaping into the home or building environment.

The effectiveness of a plumbing trap relies on its design, which ensures that even as water and waste pass through the plumbing system, the water remains in the trap to provide a constant seal. This feature is crucial for maintaining indoor air quality and preventing foul smells from permeating spaces where people live and work.

While other functions are important within a plumbing system, such as ensuring that waste flows properly or facilitating maintenance access, these are not the primary purpose of traps. Therefore, the ability of traps to control odors is essential for creating a hygienic and comfortable environment in any structure equipped with plumbing.