Ross - the magical number is 40 degrees. Not for all, as the range is between 40 and 60 degrees, but 40 is the starting point.
As for Nash, nm - they have just (relatively recently) spent £350'ish thousand on coming in to line with EU guidelines. Somewhere in amongst the vast amount of money will be a pressure cooker or a vacuum bath that doesn't quite get to 40 degrees, I imagine.