Which of the following is NOT an approved water supply material?

Lead is not an approved water supply material due to its toxic properties and the health risks associated with lead exposure. Lead can leach into drinking water, particularly in older plumbing systems, which can lead to serious health issues such as developmental impairments in children and various health problems in adults. For this reason, regulations and guidelines discourage or prohibit the use of lead pipes and fixtures in water supply systems.

In contrast, copper, galvanized metal, and PEX (cross-linked polyethylene) are widely accepted materials for water supply lines. Copper is known for its longevity and resistance to corrosion, galvanized pipes have been used for many years and are still found in many existing systems, while PEX offers flexibility, ease of installation, and resistance to scale and chlorine, making it a popular choice in modern plumbing systems.