Just a note, with water I would be prudent when selecting Kabadi Danner as mixing rule and verify the limits for this model, Huron Vidal, Cubic Plus Association or Wong Sandler when available should offer a more extendend range of application.
I agree, "standard conditions" which differ in every country can originate problems, in some cases a client may accept to use mass flows (which are equivalent units without the "standard" ambiguity) but in general there is no space for discussion.