24 replies to this topic

[Mariann]

Hi

 

If the metal detector alarms for a product, how do you mark the product, and do you place it somewhere specific to wait for further investigation?

[MDaleDDF]

We write "METAL" on the bag and take it immediately to the lab for sifting/investigation.

[kconf]

Yes, write the lot #, date & time, line. Then like MDaleDDF said, take it immediately for further investigation. In my experience, there has been 50-50 chance of finding something. 

[GMO]

It has depended on the site but in some sites the person doing the detector check does the investigation themselves, in others it's QA but it's immediate because it could signal an issue further upstream.

If you don't find anything it's worth considering if it was just too small or multiple tiny pieces and still potentially an issue if you suddenly start getting lots of "false" rejects.  (Bitter experience...)

[TimG]

I'm not sure about BRC but when I ran an SQF program that had a metal detector we were sure to put the procedure in the metal detector document, which referenced the NCP doc. Those products got placed on NCP; we had a laminated NCP placard, and any hits went right to its own NCP pallet to then be re-ran by the shift supervisor. It had to make 2 clean passes by the shift supervisor who would do it immediately after his accuracy checks. If it flagged again, he/she would rip it open and fill out disposition paperwork that I would then review when I was back in that plant.

You want to make sure any product you set aside is clearly separated/sequestered and has no chance or going through as passed product.

[kconf]

So you just separate what was rejected, right? The line that is running the lot keeps running?

[GMO]

So you just separate what was rejected, right? The line that is running the lot keeps running?

 

For one reject, keep running and investigate.  For two rejects, stop the line and assess.  For two rejects of the same type, stop the factory...

Or at least that was the M&S protocol back in the day and you can see the sense in it but it probably is site dependent.  You shouldn't have metal routinely cropping up in your product.

[kconf]

Stop the line and stop the factory even if they are discovered to be false positive later? 

[Tony-C]

Hi Mariann,

 

Ideally you will be rejecting into a locked cage and then QA will collect the product, mark it as rejected with date/time, check the rejected product by running it through the detector again and then opening and inspection/sieving as appropriate.

 

Kind regards,

 

Tony

[GMO]

Stop the line and stop the factory even if they are discovered to be false positive later? 

 

No, only if metal is found which is one of the reasons why we always did it immediately but also it's the right food safety thing to do.  If you have two rejects that look similar, e.g. pieces of metal swarf, you need to find out what is going on to cause it as you're probably missing some in your metal detector (they're not 100% effective.)

 

But that was M&S protocol, not saying you have to adhere to that but it's a good indicator of what some people think is the right way.

 

If you're having loads of false rejects, what I'd suggest you do is:

 

• Check if you've recently had any settings changed.
• See if the false rejects have increased suddenly.
• If they have, do a thorough check of your line in key areas where metal on metal contact is possible, grinding and mixing (are there any points of grinding or fresh scratches?)  Also ask key employees (e.g. ops, hygiene and maintenance) for ideas on where it might be from and what has recently changed.
• If the line is clear check ingredients.  it might even be worth metal detecting some.
• If both are clear, look at reducing your sensitivity (but only as a last resort).  Loads of false positives is a sign that you might be trying to detect at a level which is too close to your product signal.

[Mariann]

Thank you all for response. In our plant when metal detector alarms the operators investigate the product. Usually they investigate the product immediately. They write non conformance form and attached there also the metal findings and bring it to the quality. 

                                                                                                           

We had recently audit and the auditor mentioned that the product should be marked somehow, or it should go to some locked box or specific area etc. I am interested to know what kind of solutions other have. 

[GMO]

Thank you all for response. In our plant when metal detector alarms the operators investigate the product. Usually they investigate the product immediately. They write non conformance form and attached there also the metal findings and bring it to the quality. 

                                                                                                           

We had recently audit and the auditor mentioned that the product should be marked somehow, or it should go to some locked box or specific area etc. I am interested to know what kind of solutions other have. 

 

It would be interesting (or would have been) to interrogate the auditor's concerns.  The pack will immediately be rejected into a locked bin so if the operator doesn't for some reason get to it immediately then there's no risk, albeit that shouldn't be left there long so it can be investigated.  If it's removed and left for some reason, why?  Why not investigate straight away?  Lastly if you're putting that pack through the same metal detector, not an off line one, then their concerns are valid.  You want to make sure it's not going to go back into normal production.  Some retailer standards in the UK allow a pack to be put back in if it's been re metal detected 3 times in 3 different orientations and not set off the detector but I'd never advocate this as good practice personally.

 

So I guess if you do have that concern, just get some labels near your metal detector, e.g. labels marked with "metal reject" in red and stick them on anything taken out of the bin.  That's one solution if the above concerns are what they had?

[SHQuality]

Yes, write the lot #, date & time, line. Then like MDaleDDF said, take it immediately for further investigation. In my experience, there has been 50-50 chance of finding something. 

 

Hi Mariann,

 

Ideally you will be rejecting into a locked cage and then QA will collect the product, mark it as rejected with date/time, check the rejected product by running it through the detector again and then opening and inspection/sieving as appropriate.

 

Kind regards,

 

Tony

Surely the lot and time codes are already on the package?

[Tony-C]

Surely the lot and time codes are already on the package?

 

Possibly, but this is a pack of strawberries, it should have a lot code that corresponds to the date, but not always, and it is easier to record the date at the time.

 

The time packed isn't always recorded and that might not even be the time it went through the metal detector.

 

Kind regards,

 

Tony

[jfrey123]

Hi

 

If the metal detector alarms for a product, how do you mark the product, and do you place it somewhere specific to wait for further investigation?

 

Anything flagged by MD needs to be isolated, period.  If it's a case detector, my plants have alarms/lights and the operator has to isolate the case onto a "reject" labeled pallet or area for evaluation.  If it's an inline MD of unpackaged product (belt or gravity feed) you'll have a diverting system that rejects the steam into an isolation area that is also labeled.

 

Everywhere I've worked had policies about continuing processing when MD is triggered depending on frequency: they can continue at maybe 1-3 rejects in say maybe an hour, with the caveat that all MD rejections are evaluated prior to positive product release for shipping.  But even with that, when the MD start going bananas, it should trigger shutdown and investigation mid-processing.  All scenarios of how you will react to MD rejections should be covered in the SOP.

[Tony-C]

Anything flagged by MD needs to be isolated, period.  If it's a case detector, my plants have alarms/lights and the operator has to isolate the case onto a "reject" labeled pallet or area for evaluation.  If it's an inline MD of unpackaged product (belt or gravity feed) you'll have a diverting system that rejects the steam into an isolation area that is also labeled.

 

Everywhere I've worked had policies about continuing processing when MD is triggered depending on frequency: they can continue at maybe 1-3 rejects in say maybe an hour, with the caveat that all MD rejections are evaluated prior to positive product release for shipping.  But even with that, when the MD start going bananas, it should trigger shutdown and investigation mid-processing.  All scenarios of how you will react to MD rejections should be covered in the SOP.

 

  3 rejects an hour would indicate something was seriously wrong jfrey123?

 

Kind regards,

 

Tony

[jfrey123]

  3 rejects an hour would indicate something was seriously wrong jfrey123?

 

I'd say it depends on the product and process types.  At my original spice plant it was 10 per hour to trigger a stop and investigate, and even then we got pushback from customers and auditors that we weren't being attentive enough.  But dried veggies ground into spices have an inherently high risk of metal to where it's almost 'expected' to be in the product.  We would routinely find metal, which we'd investigate to ensure wasn't part of our machinery, then inform the clients who owned the product of the findings and ask what they wanted to do with it (as we were just a 3PL processor/packer).

 

In my fresh fruit and veg facilities I work for now, we have enough staff to immediately start reviewing the rejected trays and I think they do so at 3 in an hour.  They'll continue running while QC evaluates, but depending on what they find it can trigger a shutdown because we really don't expect metal to be found in fresh fruit and vegetables, and our cutting is pretty manual with only a handful of automated peeling/slicers being used.

[GMO]

I used to work with root veggies and had nothing like that level of rejection.  Just saying...

[jfrey123]

I used to work with root veggies and had nothing like that level of rejection.  Just saying...

 

Root veggies as in fresh?  We rarely have any metal rejections at my 9 fresh veggie handling sites, so I agree.

 

But diced/shredded dehydrated veg is heavily machined, then often laid out for open air drying in the lesser developed countries or even China.  Then it gets milled in those same countries or sent to places like my old spice plant for milling into granulated or fine powders.  Metal embedded in those dried hunks from processing equipment (transfer augers, slicers, grinders, automatic graters, etc.) was pretty frequent.  The spice industry seems to rely heavily on the old 7-25mm guidance the FDA had put out ages ago, and they install lots of inline magnets post powder grinding if you care to infer a reason as to why...

[GMO]

Root veggies as in fresh?  We rarely have any metal rejections at my 9 fresh veggie handling sites, so I agree.

 

But diced/shredded dehydrated veg is heavily machined, then often laid out for open air drying in the lesser developed countries or even China.  Then it gets milled in those same countries or sent to places like my old spice plant for milling into granulated or fine powders.  Metal embedded in those dried hunks from processing equipment (transfer augers, slicers, grinders, automatic graters, etc.) was pretty frequent.  The spice industry seems to rely heavily on the old 7-25mm guidance the FDA had put out ages ago, and they install lots of inline magnets post powder grinding if you care to infer a reason as to why...

 

Fresh both whole and diced.  Never those issues.  I've also used loads of dried herbs, spices and veggies too in various industries from seasoning mixes to ready meals, soups and other products and again, never had those levels of issues.

Isn't it worth sorting it with your suppliers?  Sorry to be simplistic about it.  Why are you using suppliers where bits of their machinery are ending up in your products?  Or who are using really large test piece sizes where that's uncalled for?

Edited by GMO, 02 December 2025 - 09:40 PM.

[Tony-C]

Isn't it worth sorting it with your suppliers?  Sorry to be simplistic about it.  Why are you using suppliers where bits of their machinery are ending up in your products?

 

No need to apologise GMO, there is no way up to 10 rejects an hour should be acceptable.

 

The suppliers would need to be tackled and action taken to reduce this 'expected' level of contamination. In the meantime I would be looking for a new supplier.

 

Kind regards,

 

Tony

[GMO]

No need to apologise GMO, there is no way up to 10 rejects an hour should be acceptable.

 

The suppliers would need to be tackled and action taken to reduce this 'expected' level of contamination. In the meantime I would be looking for a new supplier.

 

 

I suppose I'm apologising because I'm not wanting to be rude because I do understand how things can become "a norm" in an organisation and that's nobody's fault but that's why ifsqn is good because it can bring together people with a lot of experience who can bring that to discussions in a "hang on... that doesn't sound quite right" kind of way.  I've certainly done a lot of my learning "on the job" and so sometimes the ability to know when things feel "off" isn't there if it's a category I don't have a lot of experience in.  Just to me, this feels a little "off" from the experience I do have.  I just want to share without trying to make the OP feel bad because we've all been there and had those "Huh.  Really?" moments.

[jfrey123]

Fresh both whole and diced.  Never those issues.  I've also used loads of dried herbs, spices and veggies too in various industries from seasoning mixes to ready meals, soups and other products and again, never had those levels of issues.

Isn't it worth sorting it with your suppliers?  Sorry to be simplistic about it.  Why are you using suppliers where bits of their machinery are ending up in your products?  Or who are using really large test piece sizes where that's uncalled for?

 

It's been just over 10 years since I worked for that company, and we were a 3PL toller/packager:  we didn't control the suppliers, the owners of the product we processed did.  All we could do is report what we were seeing and ask them what they wanted to do with the product.  I speculate the product we were receiving was always "intended for further processing" and hadn't been subject to a screening prior to coming to us, which could explain the discrepancies in our experiences.  Example:  we were getting most materials direct from farms or the dicing/drying operations, whereas you were likely getting your finished spices and herbs from a processor like us who had better controls in place.  And I do want to point out there's a difference in using cut root veg, spice, or herbs in a finished retail dish versus processing 100,000lbs of granulate/powders a day.  A dedicated spice processor is going to find more contaminants in the material than a company packing retail and adding a few grams to their dishes.

 

Maybe I'm giving the wrong impression when I mention the frequency.  It wasn't as if every day there would be 10 rejects an hour, that was merely our critical limit to trigger a shutdown of either a mill or a packaging line where open stream detectors were being used prior to final packaging.  Most runs day to day had far fewer rejections that would be evaluated at the end of the lot run to determine whether it was a widespread issue or not.

 

Our final CCP was a case MD.  Even then, our process was to isolate a rejected full case and continue unless we reached that limit (which never happened at that level).  It didn't make sense to the owners, customer clients, nor even our auditors to full stop a packaging line for a case rejection when we had a positive release system that required us to investigate rejections prior to releasing products.

[GMO]

I don't doubt you're right that your processing of large volumes will make a difference but even so.  Sounds high.  Especially if it was sourced back to the processing of the ingredient and damage.  We bought from herb and spice processors who would also supply retailers and some of those in the UK ask you to stop the line when you have two rejects or stop the factory if there's two of the same type.  Then contact them before you restart.

[jfrey123]

I'm just sharing my experience.  If we shut down the factory and called these large name spice retailers for every 2 md hits (names Americans would know), they would've screamed bloody murder.  After our process, the finished material we sent them passed their own MD standards when they either resold in bulk or bottled for retail sale.  So maybe that's another disconnect as we were a mid-step processor not serving the retail public, we were doing all B2B 3PL in bulk.  Say what you want, even the one FDA inspection that occurred while I worked there didn't find a fault in how they did it.  Perfect?  Probably not.  Reality in the spice industry?  Probably.

 

Past that, no factory I've worked in or consulted to would shut down the entire factory for 2 md hits.  That's why locked reject bins exist on md's and why positive release programs exist.  In my current plants they'll evaluate the rejects in real time, but we won't shut down unless something is discovered and other corrective actions are written into SOP.  In my current biz we won't stop cutting watermelons in processing just because the cut mangos on the packaging line had a md hit.  Different story if they find pieces of an auto chopper or bits of a broken knife, but we have numerous other controls to catch that before it even gets to packaging.

 

Anyway, I've detracted from the OP's original post enough.  My original point was many facilities I've worked in/with will segregate MD rejections to evaluate after the run is complete unless some critical limit is reached to trigger a stop and investigate.

Edited by jfrey123, 11 minutes ago.