And in current WHO Annex 6 the following is stated:
"3. Sanitation
3.1 The sanitation of clean areas is particularly important.
Appropriate cleaning validation should be carried out to ensure disinfectant residuals can be detected and are removed by thecleaning process ." End quote
So the interpretation of these statements can be as follows:
“Generally aftereach application of diluted disinfectant on clean room surfaces for the valid wet contact time , the disinfectant residues remaining on clean room surfaces should be removed by cleaning (rinsing) the clean room surfaces (with for example Water or IPA 70% then dried)”
My questions are: 1- Is the mentioned interpretation accurate ? 2- If this interpretation is not accurate what is the accurate interpretation ? 3- If this interpretation is accurate:
what are the dangers of not removing disinfectant residues from clean room surfaces by cleaning (rinsing) after each application of diluted disinfectant ?
I want to say that my little understanding of the issue is that:
If the routine daily cleaning process is composed of first wet cleaning (without disinfectant) followed by disinfection with “diluted” disinfectant which is then dried leaving no visually obvious residues on room surfaces , there will be no chance for build up of disinfectant residues (since the first step of every subsequent routine cleaning process is wet cleaning (without disinfectant) which will remove any non visually obvious disinfectant residues remaining from the previous routine cleaning process) and always there will be no need at all for cleaning (rinsing) room surfaces after any application of diluted disinfectant for the purpose of removing disinfectant residues.
There are currently no approved or validated methods for assessing the amount of residue on non-product contact surfaces. Many or even most facilities will conduct a visual test for residues on non-product contact surfaces only. A product such as IPA 70% or Hydrogen peroxide that leaves a non-volatile residue of less than 25 ppm can be classed as no residue so don’t need to a validation study. For other commercial products, a lab-based residue on evaporation test will give a quantitative result of how much residue left behind, and if it is above 25 ppm per 100 ml, further validation work would be required.