What type of plumbing supply line piping material, still in use today, has been reported to lead around the joints?

The type of plumbing supply line piping material that has been reported to lead around the joints is Polybutylene, commonly referred to as PB. This synthetic plastic material was widely used in residential plumbing from the late 1970s until the mid-1990s, primarily due to its low cost and ease of installation.

However, PB piping has become infamous for its issues with joint failures. Over time, PB can become brittle and allow water to leak at the joints, which may lead to significant water damage in homes. This prominence of joint leaks has caused many homeowners to seek replacement with more reliable materials.

The other materials listed, such as CPVC, ABS, and PVC, do not have the same historical issues with joint integrity that PB has and are considered more stable and reliable in plumbing applications. Therefore, understanding the specific problems associated with PB is crucial for anyone studying plumbing systems and regulations related to real estate.