What Is Polybutylene Pipe?

The North Carolina Real Estate Commission says polybutylene piping is made from a plastic resin and was commonly used for a couple of decades in place of copper piping for water supply. A 2003 federal appeals court opinion describes polybutylene as a by-product of oil refining, and says Shell, the exclusive seller of the resin in the late 1970s, developed flexible polybutylene pipes that other companies like DuPont and Hoechst manufactured.

Leaks were the complaint. The commission says consumers complained about leaky pipes, especially where pipes met an insert type fitting. The Fifth Circuit says that in 1995 a Tennessee state court approved a national class settlement in the Cox case requiring Shell and Hoechst to contribute $950 million to replace eligible consumers' leaking polybutylene plumbing systems and to reimburse them for property damage the leaks caused. A Texas appeals court says a separate December 1995 aggregate settlement with two polybutylene manufacturers in individual Texas lawsuits called for cash payments totaling $170 million, plus provisions for replacing the plumbing in each plaintiff's property.

Not every system fails. The commission says that despite the Tennessee class action settlement, its own study more than a decade ago found that not all, or even most, polybutylene piping with insert fittings commonly fail.