Which of the following materials is NOT approved for potable water piping under the UPC?

The correct answer is PVC, which is not approved for potable water piping under the Uniform Plumbing Code (UPC). Polyvinyl chloride (PVC) is commonly used for drainage, waste, and vent applications due to its excellent corrosion resistance and lightweight nature. However, it is not typically suitable for potable water delivery systems because concerns regarding the leaching of chemicals into the water can arise, particularly with the ingestion of certain compounds that may affect water quality.

In contrast, materials like copper and CPVC are specifically appropriate for potable water applications. Copper has a long history of use in plumbing systems due to its durability, antimicrobial properties, and resistance to corrosion. CPVC, or chlorinated polyvinyl chloride, is also approved for hot and cold potable water distribution as it does not release harmful compounds into the water supply and can withstand higher temperatures than standard PVC.

Galvanized steel is generally acceptable for potable water, although it can corrode over time and may require more maintenance compared to some other materials. Its use has declined in modern plumbing due to these maintenance issues and the availability of better alternatives. Understanding these material distinctions is vital for plumbing professionals to ensure compliance with the UPC and to maintain safe water quality standards.