Polybutylene (PB) pipes were progressively phased out of model plumbing codes during the mid-to-late 1990s following a massive wave of plumbing failures and a landmark class-action settlement finalized around 1995. While manufacturing largely wound down during that period due to the material's vulnerability to chlorine and oxidants present in municipal water supplies, building authorities officially restricted its use in new residential construction by the late 1990s.