That was probably polybutylene. PEX has been installed even before that (since the 1950s) and proven longevity, while polybutylene piping was already beset with

That was probably polybutylene. PEX has been installed even before that (since the 1950s) and proven longevity, while polybutylene piping was already beset with lawsuits in the 1980s. As usual, the USA only does the right thing after exhausting all other options. Actually, I'm remembering there were some widespread failures of PEX-C. Hmm.