Master Plumber Practice Exam 2025 – Complete Prep Guide

Flushing non-biodegradable items should be avoided in a plumbing system because these materials do not break down naturally and can lead to significant clogs within the pipes. Non-biodegradable items, such as plastics, hygiene products, and certain types of packaging, can accumulate and create blockages over time, which may require expensive repairs or the need for plumbing services to clear the obstruction.

In residential plumbing, a key principle is to ensure that only materials that can be easily processed by the wastewater system are disposed of via the toilet or drains. Non-biodegradable items disrupt this process and can also cause damage to the municipal sewage treatment plants, further exacerbating plumbing issues.

While other options might also lead to problems, such as grease solidifying or certain chemicals corroding pipes, the immediate concern with non-biodegradable items is their tendency to build up and block flow, leading to system failures.