My contractor removed about 20 feet of pipes used for radiator heating when he moved some walls. He replaced those radiator pipes with PEX. A heater salesman (giving me an estimate on another project) saw these red PEX tubes and said the contractor used non-oxygen barrier pex, man for hot water runs not radiator heating, and therefore could damage the heating system if not treated with an additive in water. The original contractor (since fired) claims he used industry standard PEX, but I can't tell if this PEX is oxygen-barrier or not.

a) Can you guys tell if this was the right PEX to be used for radiator heating?
b) If not, what should I do now? Rip out the red pex or just apply the additive every winter?

Thanks!