Buna mihaellaaa,
On what basis were the current limits set? There is a recommendation from the equipment supplier; It seems to me very low values ...
Are the sanitation tests performed on surfaces or in rinsing water?
During the flow I do not think that the determination is relevant because the product residues interfere with the determination and the value is not exclusively microbiological contamination.
Conversion to cfu / cm2, I don't know if it is regulated somewhere.
In principle, some established maximum limits, if they are not legal provisions, must be validated. It is taken at the same time as the rapid tests, specific tests (eg yeasts and molds, enterobacteriaceae). In order to be relevant, approximately 10 determinations must be made in parallel, possibly from different areas. The results are analyzed and thus the limits are established (eg at values of: 100 RLU, 150 RLU, 170 RLU THE RESULTS OF MICRO DETERMINATIONS ARE IN LIMITS, while for the value of 200 RLU, THE RESULTS OF MICRO DETERMINATIONS ARE OUT OF LIMITS, the max limit should be to be 170 RLU, possibly for a greater precaution we put the limit 150 RLU.
In our company, these validations were performed several years ago. The limits are 150 RLU for CIP washed surfaces (both water and surface determinations) and 500 RLU for manually sanitized surfaces. The values are applicable after sanitization; I explained above that flow determinations are not relevant. The equipment and consumables are 3M brand. We tested other equipment but I did not have repeatability for measurements.
