You shouldn’t use the mdpe blue pipe above ground if you can help it because it isn’t UV stable. Instead you should use the black HDPE pipe and compression fittings.Someone on a camper forum who said he worked for hoze lock said there is no legal requirements controlling what hosepipe is made from.
This mentions legionella may be a risk too.
I have a hoze lock pipe with a timer on it feeding my polytunnel drip system every morning, plus another connecting two waterbutts, but I'm looking to change to mains water blue 25mm or food grade hose pipe soon. I have no idea if plastic from the hose can end up in my tomatoes?
Are water butts food grade anyway? These might be an alternative?