Medical apparatuses and instruments for extracorporeal blood treatment; medical apparatuses and instruments for the treatment of kidney failure; apparatuses and instruments for the preparation of liquids for medical use, namely hemodialysis liquids, substitution liquids for hemofiltration and hemodiafiltration; hemodialysis machines; hemofiltration machines; hemodiafiltration machines; hemodialyzers; hemofilters; filters for hemodialysis liquid; filters for substitution liquid for hemofiltration and hemodiafiltration; membranes for hemodialyzers; membranes for hemofilters; membranes for filters for hemodialysis liquid; membranes for filters for liquids for medical use, namely hemodialysis liquids, substitution liquids for hemofiltration and hemodiafiltration