4 replies to this topic

[QualityNewbie]

Hi, I am pretty new to the QA field, no degree in food science, HACCP and PCQI trained. I've scoured google to find an answer to this question from my most recent SQF audit. our facility produces masa flour, so dry product, we got hit on 2.4.8.3, due to a presumptive positive for salmonella .spp that was retested and came back negative, our procedure does not have any direction for a presumptive, only a confirmed positive. which is after a confirmed positive, thoroughly clean the area around the positive swab, and then have 3 weekly swabs consecutively negative. The auditor was using an email where we told an employee to go clean the area and retest, to assume we were treating it as a confirmed positive, and based on that assumption, we "did not follow our procedure". I would love some feedback if you thought this was correct or not. I don't know if he is wrong, just trying to find the correct answer.

[MDaleDDF]

I'm confused.   You got a presumptive positive on a surface in your facility, or on finished product?   How did you get a 'presumptive positive'?  For me, there's no such thing as a 'presumptive positive'.   You can't retest your way out of a dirty test, doubly so on finished product.   

 

So if it was on a surface swab, we reclean per the SOP and retest.   If it comes back dirty again it triggers a CAR, SOP review, HACCP team meeting, training of staff and all that fun stuff, because obviously the SOP isn't working correctly, or isn't being followed, etc.

 

If this was a 'presumptive positive' on finished product, gotta know more about what that term means.   If it means you got a positive result, but call it presumptive because another sample came back clean, that's bad juju.   If you're not on a positive release program, I'd switch to that so in the future any issues can be dealt with before product hits the streets.

 

As far as following your procedure, you should have a written procedure stating what exactly it is you do in the event of a positive hit.   You need to follow that to the letter....

Edited by MDaleDDF, 03 April 2026 - 11:22 AM.

[Scampi]

Salmonella presumptive positive is that your swab tested positive for general salmonella, but needed to be typed, and when the lab did that, it was negative for a pathogenic variety (e.g salmonella Enteriditis )

 

What the sample is telling you is that your facility isn't as clean as it ought to be........

 

I don't think your auditor is correct, you should have proceeded as if it were a confirmed positive UNTIL you heard back from the lab

 

what exactly did the auditor think you should have done instead?

 

when we swab our facility, it gets a full reclean post swab so that we can continue regardless of the current outcome (otherwise we'd have to withdraw all the product made post swab )

[GMO]

You can also get presumptive positives which don't confirm for any type. I'm always suspicious on whether they really are then a negative. I've certainly found retests which fail when presumptives didn't confirm.

 

I'm a little confused by the scenario so I'll write it out and see if I understand it. You can correct me OP!

 

• You have a positive swab.
• Your corrective action is to clean and retest.
• But you put this action in place on a presumptive (that's good IMO to treat as a positive till you know otherwise.)
• Are you saying you didn't do the other follow up swabs because it was a presumptive which then didn't confirm?

 

My question is perhaps not what the auditor was getting at. But I always used to do the full retest protocols on presumptives and sometimes one of them did confirm as I said above. So that's a thought.

 

Either way, whether it was a positive or only a presumptive, was the auditor perhaps alluding to even if you did have a positive, recleaning and retesting isn't really a preventive action as a result of an RCA? If it had been positive, should you not be doing more? 

 

Anyway, let me know if I've got the wrong end of the stick.

[liberator]

You should always have a process in place for any presumptive positive pathogen results. If you get a presumptive positive you should enact your process as you detailed:

 

"only a confirmed positive. which is after a confirmed positive, thoroughly clean the area around the positive swab, and then have 3 weekly swabs consecutively negative"

 

Always treat a presumptive pathogen result as if it was a positive pathogen result. 

 

Why do you need to do this? So you get a presumptive positive, and you do nothing, you took the swab four days ago, and get the presumptive now, so you wait another 2-3 days for a confirmation of a positive or negative. It comes back positive, so you now have had a positive pathogen in the environment and your manufacturing facility for 7 days or so.

 

In that time that pathogen could have spread within your facility and there is a risk of it potentially contaminating your product. The pathogen gets spread around by people and process, so that means more pathogen swabs come back positive, more swabbing, cleaning, sanitising and testing, nip it in the bud before it gets too big to control.

 

If it spreads then you could wind up having positive pathogen in your product. You don't want a pathogen in your facility, especially salmonella in a flour plant. Result, line shut down, lost product, time and a full strip down and clean of your plant then a further intensive swab and finished product pathogen testing and many more $$$ to your budget.

 

If the presumptive comes back negative, all that's happened is you lost a bit of time and $  to clean and sanitise and a few extra swabs.

Edited by liberator, 12 April 2026 - 10:18 AM.