This is all I found, Martin:
Most oxygen-barrier PEX does not have the appropriate approval codes for use with potable water and should not be installed in domestic plumbing applications. Uponor’s hePEX recently received NSF approval, making it one of the few types of oxygen-barrier PEX on the market that can also handle domestic water.
from:
http://blog.supplyhouse.com/dual-approved-hepex-from-uponor/