Polybutylene Plumbing Litigation Lawsuit

Polybutylene Plumbing Litigation

The polybutylene plumbing litigation is a body of U.S. consumer product litigation brought by homeowners whose polybutylene water lines — marketed as Poly-B — developed leaks and ruptures that caused water damage to their homes. Owners in Texas and other states sued the pipe's makers, and the claims were consolidated in multidistrict litigation. The lead case, Cox v. Shell Oil, was settled. The case record does not preserve a filing date, a termination date, or a settlement year for the matter.

Product and manufacturer

Polybutylene (PB-1) is a semi-crystalline polyolefin plastic produced by polymerization of 1-butene. In construction it was valued for being flexible, weldable, corrosion-free, and quiet, and it was used widely for hot and cold drinking water distribution in newly built homes across the United States and Canada. Millions of homes built roughly between 1978 and 1997 have polybutylene plumbing installed. In the U.S. litigation, the lead case — Cox v. Shell Oil — named Shell Oil as the defendant, with the homeowners' claims directed at the makers of the pipe.

The defect and the harm

The core problem with polybutylene piping is chemical degradation. Evidence indicates that chlorine and chloramine compounds present in municipal drinking water — substances deliberately added to retard bacterial growth — attack the internal chemical structure of polybutylene pipe and the associated acetal fittings. The reaction is greatly accelerated by tensile stress, so failures are most often observed where the material is under the highest mechanical stress, such as at fittings, sharp bends, and kinks. Localized stress whitening of the material generally accompanies and precedes polymer breakdown. Because the reaction takes place inside the pipe, the extent of deterioration is often difficult to assess, and the system can produce both slow leaks and sudden pipe bursts without prior warning. For homeowners, the consequence was water damage to floors, walls, and contents. The only durable remedy generally cited is replacement of the polybutylene plumbing throughout the building.

Litigation

Homeowners in Texas and other states brought class action claims against the pipe's makers over the leaking and broken lines. The claims were consolidated in multidistrict litigation, and the lead case, Cox v. Shell Oil, was settled. The case record does not document a filing date, the identity of the court, a docket number, or the year of settlement, and no trial or jury determination is recorded for the consolidated action. It is archived as a matter that resolved by settlement.

Aftermath

Following the widespread failures, polybutylene water pipe was dropped from acceptance in U.S. building codes and is no longer sold for that use in North America. In Canada, the National Plumbing Code listed polybutylene as acceptable in its 1995 issue and removed it from the acceptable-for-use list in the 2005 issue. The litigation is one of the better-known examples of a long-service-life building material being reassessed after in-service degradation proved faster than expected.