Arizona Plumbing Practice Exam

What is the maximum allowable percentage of lead in solder used for potable water?

1. 0.1%

2. 0.2%

3. 0.3%

4. 0.5%

The correct answer is: 0.2%

The maximum allowable percentage of lead in solder used for potable water is 0.2%. This standard is established to ensure the safety and health of drinking water. The reduction of lead content in plumbing materials, particularly solder, is a critical step toward minimizing lead exposure, which can have serious health implications, especially for vulnerable populations such as children and pregnant women. Historically, lead was commonly used in solder and plumbing systems, but legislative changes and growing awareness of its toxicity have led to stricter regulations. The standard of 0.2% aligns with regulatory frameworks like the Safe Drinking Water Act in the United States, which aims to protect public health by limiting lead in drinking water systems to safe levels. This knowledge is essential for plumbers and anyone involved in designing or maintaining systems that deliver potable water.