Yes, my apologies as well, I also did not intend to hijack your thread Caz.
I got the fundamental differnece between validation/verification (validate = make sure it happens, verify = make sure it is effective) - I possibly had a moment of not sober that influced that error post It's pretty embaressing cuz that's like QA 101, so I feel sufficeintly like an untrustworthy, overzealous moron now.
I do take EMP E Bac swabs of food contact surfaces, considered salmonella & e coli but decided it was too risky on negative release...My problem there is that E bac levels don't correspond to any other levels, so they aren't the best indicator organisim.
So for a validation study, the steps in general would be :
1. Clean the equipment
2. Take an ATP swab
3. Take a sample with a method that tests for .. specific pathogens / microbes / "little guys" (Total coliforms, listeria, APC)? Or just the thing you are trying to clean off (Chocolate test! I guess for Caz in a dairy casein test?)
4. Ideally, once you started seeing positive results that breach limits for your second test, the ATP test would be also above a certain level
(For ex - Your spec limit is 5 horsepowers in Finished goods. You know if the surface has less than 5 horse powers, your FG will be in spec. During your study, every time your 2nd test shows 5 horsepowers present on the surface, your ATP is always higher than 30, but when there are 4 horse powers present on the surface, ATP is only 25)
5. You set your limit at the ATP level highest that corresponds to the 2nd test still passing spec.
6. Caveat - Turns out ATP levels don't actually correspond to anything, so if you do end up with results that make sense, take that lucky streak right on down to the bar and fill out a march madness bracket, then buy fancy $10 scratcher tickets.
"I take an ATP swab and a EMP swab every start up, and every time I've had a hit on my EMP swab, ATP levels have been above #, so that number is my limit for pass/fail"
Back to off topic though - I understand that if you put sanitizer over something dirty it's only going to sanitize the surface of the dirt/bio film, which will be dispruted by turbulence during the process and be useless, so I can totally see the value of swabbing pre sanitizer to avoid false negatives or soaking your swab in a part that's still wet with sanitizer would give you false negatives. What I don't understand is what the sanitizing step does afterward. Do you clean, swab, sanitize, swab? Like post clean and post sanitize are different limits because you're doing CIP, and they are totally separate steps in your process? (I do not envy the vigorus CIP cycles and tank holding limits of dairies)