Which of the following materials is NOT commonly accepted for plumbing installations in Massachusetts?

Lead is not commonly accepted for plumbing installations in Massachusetts due to the health risks associated with lead exposure. Lead has been proven to contribute to various health problems, particularly in children, making it a hazardous choice for drinking water plumbing systems. As a result, many states, including Massachusetts, have enacted regulations that prohibit the use of lead in plumbing materials.

In contrast, copper, PVC (polyvinyl chloride), and PEX (cross-linked polyethylene) are widely accepted and utilized materials for plumbing installations. Copper is durable and resistant to corrosion, PVC is lightweight and easy to install for drainage and venting, and PEX offers flexibility and resistance to scale and chlorine, making it a popular choice for potable water systems. Therefore, the choice of lead as a plumbing material is considered unsafe and is effectively banned in modern practices within Massachusetts plumbing regulations.