All,
I developed a cleaning method for our production vessels. Our production staff did a cleaning of one of our vessels via the method, a 2000 gallon pressure vessel. I collected an initial rinse sample, then the vessel was cleaned per the method with an alkali cleaner, then a final rinseate sample collected. I had the samples tested for HPC, Total coliform, and E. Coli. The initial rinseate sample came back positive for Total coliform (little scary), and was > 5,700 cfu for HPC. The final rinseate sample came back negative for E. coli and Total coliforms and 28 cfu for HPC. I would have done a swab (think this would have been better than rinseate), but to get into the kettle to do a proper one would require a Confined Space training and permit, which none of us have. Also, the rinseate was collected after use of the alkali cleaner but before use if the sanitizer.
Questions:
1) Is the testing I'm doing valid? Is there another way that's better?
2) Should the final rinseate sample been collected after the sanitizer? The method does call for a sanitizer to be applied after use of the cleaner.
3) Am I using the right test to validate?
4) How many cleanings do I need to do and samples I need to collect to prove I have validated?
5) Is the final rinseate reading OK? Do I need a final reading of 0 cfu?
Any input would be greatly appreciated.
Thanks,
Gary