Recommendations/guidelines regarding the microbiological and chemical quality of fluids in dialysis are increasing in numbers, both nationally and internationally. As dialysis is a worldwide issue, with many elements being similar regardless of geographical area, it is logical to have the same quality requirements on fluids used in dialysis. At present, there are large differences between the different documents. This situation makes studies where several nations participate more difficult to interpret as the fluids used in dialysis are crucial for the dialysis session.
A special situation applies for substitution fluid produced ‘On-Line’ for haemodiafiltration (HDF) and haemofiltration (HF), where some recommendations are questionable from a scientific standpoint.
The International Organisation for Standardisation (ISO) is in the process of finishing a collection of standards including guideline for fluids in dialysis (water, concentrates, dialysis fluid, substitution fluid) and equipment used for water preparation. To have the same quality for reference worldwide will facilitate the interpretation of international studies as well as give dialysis patients treatments based on the same quality baseline.