Pure water that is used within the pharmaceutical industry is classified into 3 types: Type 1, Type 2 and Type 3. Out of the three types, Type 3 is the least pure in quality and is used in applications such as producing cleaning agents and diluting ingredients down to the required strength. Even though the purest water is not required, it is still important for Type 3 water to be thoroughly cleaned to stop bacterial contamination within labs and when used as a component within medicines.
To purify the water to this level and ensure no scale build up, particulates and organics need to be removed from the water before the reverse osmosis stage. This will further the filtration by removing ~99% of bacteria, ions and dissolved solids from the water. A polishing stage removes all remaining salts and ions using deionisation resin, before going through final ultraviolet sterilisation to control the future growth of bacteria and microorganisms within the water when it is stored.