Go to the web sites of the main players of plastic pipe fittings in the
UK.

I hadn't realised that Hep20 was PB. A quick browse shows:

Hep20 = PB
Speedfit = PEX
Marley Equator = PEX
Polyplumb = PB

I wonder if the PB using manufacturers know about the US liability issues?
I'll certainly be keeping to the PEX versions, myself.

Christian.