28/29 April 2021
In the middle of 2019, the WHO published the draft of the guideline entitled "Production of water for injection by means other than distillation" for the production of WFI by non-distillative methods. This finalised guideline has now been published as Annex 3 in the WHO Technical Report Series (TRS) 1025.
The five-page document (with unchanged seven chapters) has thus gone through two discussion cycles, with most of the comments ultimately aimed at Quality Risk Management, the introduction of warning and action limits and the deletion of the pH test point. However, the document does not provide any precise specifications in this regard, nor does it provide any precise specifications for warning or action limits. Overall, the document remains unspecific and thus close to the draft. A new feature is the specific mention of TOC and conductivity, which are to be monitored by means of online measurements. The pH value has been meaningfully deleted as a test point in monitoring. The requirement for zero risk of contamination of the produced WFI was also deleted and replaced by the demand for controls to minimize this risk. The use of rapid microbiological methods is recommended.