Metal Detection - is it a Monitoring Activity or a CCP?

Hey FSSM, I finally worked out why this topic has been so popular.

So clever from you...



It´s amazing how each time somebody post a point of view the result goes the other way, and finally this result in general standards. The prescriptive ones, might only have place for specific products, proccesing situations, etc.

FSSM

Charles

Is this your definition of a CCP or is it a quote from somewhere else?

I think the first question we have to ask, before considering whether metal detection is a critical control point, is what would be the effect of metal within the product, i.e. what harm would occur to the consumer should metal be within the product itself. This must be answered as part of the justifications process within the HACCP study. To answer this question we need facts to base our justifications on. We also need to consider the severity of the harm (should it have occurred) to give a balanced discussion. Following this argument we can apply a "multiplier" score to enable next steps.


Sorry to overdo the discussion but the first question is "what is the likely severity of the hazard that may occur" followed by "what is the likelihood of it occurring" and in most processes the severity of the hazard would be minimal - dental injury possible and the likelihood (if there are control measures in place) is likely to also be minimal. These sweeping statements are made on >30 years in the industry.

It could be argued that metal detection would be a control point and not a critical control point. However to get away with not having the process step as a critical control point you would have to show good controls, measuring and monitoring. 

This is my first post, it may be contentious!

I think the first question we have to ask, before considering whether metal detection is a critical control point, is what would be the effect of metal within the product, i.e. what harm would occur to the consumer should metal be within the product itself. This must be answered as part of the justifications process within the HACCP study. To answer this question we need facts to base our justifications on. We also need to consider the severity of the harm (should it have occurred) to give a balanced discussion. Following this argument we can apply a "multiplier" score to enable next steps.


Sorry to overdo the discussion but the first question is "what is the likely severity of the hazard that may occur" followed by "what is the likelihood of it occurring" and in most processes the severity of the hazard would be minimal - dental injury possible and the likelihood (if there are control measures in place) is likely to also be minimal. These sweeping statements are made on >30 years in the industry.

It could be argued that metal detection would be a control point and not a critical control point. However to get away with not having the process step as a critical control point you would have to show good controls, measuring and monitoring. 

This is my first post, it may be contentious!

Dear Jules,

Nice to hear from you and Welcome to the forum

Contentious is good ! (Well, most of the time anyway

This whole topic has probably generated the maximum number of posts on this forum.
From memory, the US-FDA hv a compliance guideline of longest dimension of max. 7mm based on their own data (I think) / successful prosecutions. Some people hv used this as CCP critical limit, others as you know simply quoted their machine performance. All these proposals seem to be auditorily acceptable as long as supporting docs exist.

Codex hv issued a very nice document on "validation" which includes a metal detector worked-example aligned to CharlesChew's proposal (Link is in another thread). So I guess one can validate it either way.

Rgds / Charles.C

Maybe you can look a metal detecer as a sieve ,but not the same elements.

METAL DETECTOR: A Monitoring Activity or a CCP?
Generally, most companies in the food industries today have Metal Detectors in their process lines designed for the purpose of detecting metal hazards. Often this step of the process is considered significantly risky to be classified as a CCP (Critical Control Point) - most food auditors insist it is anyway.

The issue that I am arguing here is that a Metal Detector does not "change the product or ingredients" in shape, by improvements, in aroma, or product enhancement or alterations of any sorts". Instead, all that it does is to alert any presence of ferrous hazards in the product when detected.

And, when ferrous hazards are detected, it is often at the end of the procees line meaning it is way too late hence, rendering the product not safe for public consumption.

The argument here is if a Metal Detector is deemed a CCP, where and what is the CONTROL POINT that support the process step in making food safe or to be safe?

Unlike a sieve which does change the shape of the product or ingredients, why then should we classify a Metal Detector as a Critical Control Point when itself is NOT a Control Point in the Process at all.

If we agree to this line of argument, shouldn't we correctly classify the Metal Detector as simply a monitoring function and as important as it is, be termed as a "Critical Monitoring Step" instead of a "Critical Contol Point / Step" or as I like to term it "Quality Control Point"

As a "Critical Monitoring Step" it would just be a record keeping procedure whilst categorising it as a CCP would certainly attract the auditor's attention and viewed from a more serious angle. (Mind you, calibration remains a requirement anyay you take it)

What is the general consensus? A "Critical Monitoring Step / Quality Control Point"" or a "Critical Control Point" ?

Cheers

Charles Chew

Don't want to throw a wrench in the works' but in a modern flour mill majority of the mills including mine are a closed system not touched from grain to bag and guess what my ccp is the metal detector at the end of the process before pallitizing. My question to all of you flour millers out there? if we can pull sub-micron size metal, both fe and non-fe from our product "your basic dust", Whats the point of metal detection at the end when its only detecting metal 1.25mm fe and 2.5mm non-fe? and industry standard requires this.

Don't want to throw a wrench in the works' but in a modern flour mill majority of the mills including mine are a closed system not touched from grain to bag and guess what my ccp is the metal detector at the end of the process before pallitizing. My question to all of you flour millers out there? if we can pull sub-micron size metal, both fe and non-fe from our product "your basic dust", Whats the point of metal detection at the end when its only detecting metal 1.25mm fe and 2.5mm non-fe? and industry standard requires this.

Any comments from the flour men and women?

Don't want to throw a wrench in the works' but in a modern flour mill majority of the mills including mine are a closed system not touched from grain to bag and guess what my ccp is the metal detector at the end of the process before pallitizing. My question to all of you flour millers out there? if we can pull sub-micron size metal, both fe and non-fe from our product "your basic dust", Whats the point of metal detection at the end when its only detecting metal 1.25mm fe and 2.5mm non-fe? and industry standard requires this.

If you can prove that this last metal detector can not reduce risk any further than the previous piece of equipment in the process, and there are no further risks after the previous piece of equipment removing metal then I think the metal detector could be argued to be a CP rather than a CCP.

Most flour mills use alot of magnet and sifters in various forms throughout the process and it really depends on the position and size of each piece of equipment.

A few things to consider in understanding the risk

as a general rule magnets will not pick anything that is not magnetic, eg FE only. Although in some cases non magnetic material can pick up a small magnetic charge when "worked", but this is not retained for long.

do you use sifter stacks?, if so is the wire SS?. Often the wire used in sifter stacks is around 300um diameter, consider how you manage breakages and how your process is protected against wires that potentially could up end and go through a sifter with an aperture >300um. The smallest sifter I have seen in a flour mill is 700um.

what material is the pipework post the last magnet/sifter?, how are sections joined?, are welds of good quality and inspected prior to commissioning.

Hope this helps

Couple thoughts based on US meat/poultry experience, which uses regulatory, rather than pure scientific (Codex), HACCP:

• In order to require a metal detection CCP, would you not have to had conducted a risk analysis that resulted in a determination that the presence of metal meeting the definition of a food safety hazard in finished product was 'reasonably likely to occur'? Along the lines of Risk = Severity X Likelihood...
• If we determine screwdrivers, large bolts and other items not meeting the definition of a food safety hazard may be 'reasonably likely to occur', then metal detection would be appropriate, but would not be a CCP under HACCP. What would you call it?

• In order to require a metal detection CCP, would you not have to had conducted a risk analysis that resulted in a determination that the presence of metal meeting the definition of a food safety hazard in finished product was 'reasonably likely to occur'? Along the lines of Risk = Severity X Likelihood...
• If we determine screwdrivers, large bolts and other items not meeting the definition of a food safety hazard may be 'reasonably likely to occur', then metal detection would be appropriate, but would not be a CCP under HACCP. What would you call it?

I have screwdrivers, bolts etc covered by a prerequisite maintenance procedure including toolbox inventories and audits, a parts control system etc which should then remove the 'reasonably likely to occur' conclusion.

The Codex guidelines define a critical control point (CCP) as "a step at which control can be applied and is essential to prevent or eliminate a food safety hazard or reduce it to an acceptable level".

"Essential" is the key word here. Let's say your metal detector is calibrated to detect and reject a 4mm stainless test wand but will not reject a 3mm stainless test wand.
Is a 3mm piece of stainless steel a food safety hazard? Perhaps. In that case the metal detector is not "essential" to prevent or eliminate a food safety hazard. Therefore it is not a CCP.
Science is also key here. Will the metal detector reduce a food safety hazard to "an acceptable level"? HACCP is supposed to be "scientific and systematic". I have not been able to find any scientific study that says ingesting a 3mm piece of stainless steel is either "safe" or "unsafe". That makes setting a Critical Limit for the metal detector rather difficult.

Also, a metal detector is probably not going to reject a product that is contaminated with glass, brittle plastic, etc., Once again the metal detector is not "essential" to prevent or eliminate a food safety hazard".

If a hazard has been identified at a step where control is necessary for safety/and if no control measure exists at that step or at any other, then the product or process should be modified at that step, or at an earlier or later stage, to include a control measure.

If you have documentation that there have been instances of metal contamination in your product, then the metal detector should indeed be a Control Point. I just don't think, based on the above, that it's "Critical".

AFAIK, the distinction between a Control Point and a Critical Point is purely legal. If you say your metal detector will "prevent or eliminate a food safety hazard or reduce it to an acceptable level", and someone is injured by a 3mm piece of stainless steel, you open yourself up legally.

All that being said, in the baking industry here in the USA, metal detection as a CCP is pretty much the industry standard.


Marshall

Always seemed to me its a monitoring activity, but if auditors are expecting to see it as a CCP its often easier to give them what they want than to argue with them. What's fascinating to me is the inconsistency in requiring metal detectors at all - I know of several audits in which companies who process involves considerable metal-on-metal contact had no metal detector, and a consultant was able to convince to auditor to let it slide. Lesson: metal detector - $15,000; a consultant with great BS abilities - Priceless.

Dear All,

A few {FDA quoted) comments -

Ingesting metal fragments can cause injury to the consumer. These injuries may include dental damage, laceration of the mouth or throat, or laceration or perforation of the intestine.
FDA’s Health Hazard Evaluation Board has supported regulatory action against products with metal fragments 0.3 inch (7 mm) to 1 inch (25 mm) in length. The Federal Food, Drug, and Cosmetic Act (the FFD&C Act) prohibits interstate commerce of adulterated foods (21 U.S.C. 331). Under the FFD&C Act, a food containing foreign objects is considered adulterated (21 U.S.C 342). See FDA’s “Compliance Policy Guide,” Sec. 555.425. In addition, foreign objects that are less than 0.3 inch (7 mm) may cause trauma or serious injury to persons in special risk groups, such as infants, surgery patients, and the elderly.
Metal-to-metal contact (e.g., mechanical cutting or blending operations and can openers) and equipment with metal parts that can break loose (e.g., moving wire mesh belts, injection needles, screens and portion control equipment, and metal ties) are likely sources of metal that may enter food during processing.

Control of metal inclusion

Once introduced into a product, metal fragments may be removed from the product by passing it through a screen, magnet, or lotation tank. The effectiveness of these measures depends on the nature of the product. These measures are more likely to be effective in liquids, powders, and similar products in which the metal fragment will not become imbedded.

Alternatively, metal fragments may be detected in the finished food by an electronic metal detector. The use of electronic metal detectors is complex, especially with regard to stainless steel, which is dificult to detect. The orientation of the metal object in the food affects the ability of the equipment to detect it. For example, if a detector is not properly calibrated and is set to detect a sphere 0.08 inch (2 mm) in diameter, it may fail to detect a stainless steel wire that is smaller in diameter but up to 0.9 inch (24 mm) long, depending on the orientation of the wire as it travels through the detector. Processing factors, such as ambient humidity or product acidity, may affect the conductivity of the product and create an interference signal that may mask metal inclusion unless the detector is properly calibrated. You should consider these factors when calibrating and using this equipment.

Finally, the hazard of metal inclusion may also be controlled by periodically examining the processing equipment for damage that can contribute metal fragments to the product. This measure will not necessarily prevent metal fragments from being incorporated into the product, but it will enable you to separate products that may have been exposed to metal fragments. Visually inspecting equipment for damaged or missing parts may only be feasible with relatively simple equipment, such as band saws, small orbital blenders, and wire mesh belts. More complex equipment that contains many parts, some of which may not be readily visible, may not be suitable for visual inspection and may require controls such as metal detection or separation.

DETERMINE WHETHER THE POTENTIAL HAZARD IS SIGNIFICANT.
The following guidance will assist you in determining whether metal inclusion is a significant hazard at a processing step:
1. Is it reasonably likely that metal fragments will be introduced at this processing step (e.g., do they come in with the raw material or will the process introduce them)? For example, under ordinary circumstances, it would be reasonably likely to expect that metal fragments could enter the process from the following sources as a result of worn, damaged, or broken equipment parts:
• Mechanical crabmeat pickers;
• Wire-mesh belts used to convey products;

• Saw blades used to cut portions or steaks;

• Wire from mechanical mixer blades;
• Blades on mechanical chopping, filleting, or blending equipment;

• Rings, washers, nuts, or bolts from breading, batter, sauce cooling, liquid dispensing, and portioning equipment;
• Injection needles;
• Metal ties used to attach tags or close bags;

• Can slivers from opening cans.
Under ordinary circumstances, it would not be reasonably likely to expect that metal fragments could enter the food from the following sources:
• Utensils used for manual blending, cutting, shucking, or gutting;
• Metal processing tables or storage tanks.

http://www.fda.gov/d...e/UCM252440.pdf
(2011)

Rgds / Charles.C

Thank you Charles - some useful stuff and perhaps this is where a "combination of control measures" is applicable to one hazard.

Regards,

Tony

I have voted it as a CCP but in my experience, it can also be a Monitoring activity.

When I was working as a food safety officer in a meat processing industry we didn't have any metal detector but still our products are still safe and we haven't had any customer complaints pertaining to physical hazards on our food.
My justification why I say its a monitoring activity is that we have approved supplier program, personal hygiene sop, safe food handling sop, monitoring visitors sop, and general cleaning & sanitation SOP that control such hazards.



Regards,

food safety boy

As it it a common CCP, maybe it is a common critical major because the acceptable depends on the company's metal detection limit. In some companys 4,5 mm S.S. is a acceptable level which can be very harmful to health.

Ah this is such a long thread I can't remember whether I've said this before.

If there was something like a metal detector which was as effective for detecting glass and cost effective, it would probably be a CCP too (x-rays don't count, they're not half as effective at detecting the kind of glasses you have in production environments as the manufacturers would have you believe.)

The fact is metal detectors exist. I don't think any of us can claim they've never had a metal find on one either (unless they have fine sieves before them perhaps?) Also unlike sieving it's normally possible to detect on the finished, packed product. Given that finds are not just possible but happen perhaps every few months at least means that your prerequisites controlling metal are not 100% effective and by having this one additional step, it takes it to a level closer to 100%. So my question is, not why are metal detectors CCPs but why not? Every customer expects it. Every auditor expects it. Why make your life more difficult than it needs to be?

Don't get me wrong, if I think something is genuinely pointless, I will fight tooth & nail but I don't think this is.

Oh and a 'typical' example of a site without metal detectors is flour milling. They argue it's because their last redressers (sieves) are finer than anything a metal detector could detect. I've now experienced first hand two major metal contamination incidents with two different flour millers. So I would argue their reasoning is extremely suspect...

Five years is a long time Simon. The forum has grown and we are still hanging around. I would like to take this subject a little further but before doing so, I would like to believe that there is no one specific answer to this question and nobody is wrong so long as they can EACH validate their OWN justification for the risk characterization status that is taken.

For example -

My opinion is that the process of Magnet trappings is a "KILL STEP" which makes the last Magnet a CCP while the presence of MD AFTER loads of Magnets is purely a validation process on the effectiveness of the Magnets hence an OPRP. (In this instance, I am arguing that the process of Magnet trappings are in place to justify this risk characterization as an eliminating process. However, where Magnets do not exist, MD becomes a risk preventative / reduction process which makes it a CCP)

I certainly would like to have all your comments on this approach that I am taking.

Regards
Charles Chew

First my head hurts from reading all 15 pages of this fourm . but am going to give this a try i hope this make some Sense



So I agree with you. I think all magnets are a kill step. Personally I keep are magnets as a CP. Where the MD is the CCP because I feel you can monitor the MD more effectively than you can the magnets.



For example we clean our magnets once a shift, so about every 8 hours. What happens if your find more metal on the last magnet, do you go back for the past 8 hours and put everything on hold?



Your saying you use the MD “AFTER loads of Magnets is purely a validation process” so the way you validate that the magnet is working effectively is by the MD. So in that case if you get 1 reject you then have gone past you limit because your magnet is not working effectively? so everything need to go on hold?



See that what I am confused about because how can you have CCP then go to CP for metal when a magnet won’t pick up what a MD will? With the MD you are getting FE, Non-FE, SS so with my thinking that would be your CCP because if anything get past your magnet the MD is your last line of defense. In my though you want to validate that your MD is working properly and its going to reject if any metal get past your magnets.

First my head hurts from reading all 15 pages of this fourm . but am going to give this a try i hope this make some Sense



So I agree with you. I think all magnets are a kill step. Personally I keep are magnets as a CP. Where the MD is the CCP because I feel you can monitor the MD more effectively than you can the magnets.



For example we clean our magnets once a shift, so about every 8 hours. What happens if your find more metal on the last magnet, do you go back for the past 8 hours and put everything on hold?



Your saying you use the MD “AFTER loads of Magnets is purely a validation process” so the way you validate that the magnet is working effectively is by the MD. So in that case if you get 1 reject you then have gone past you limit because your magnet is not working effectively? so everything need to go on hold?



See that what I am confused about because how can you have CCP then go to CP for metal when a magnet won’t pick up what a MD will? With the MD you are getting FE, Non-FE, SS so with my thinking that would be your CCP because if anything get past your magnet the MD is your last line of defense. In my though you want to validate that your MD is working properly and its going to reject if any metal get past your magnets.

Agreed!


I probably said this earlier but magnets don't necessarily hold on to the contamination depending on how much there is. You can imagine the situation where you get a big load of ferrous come through, stick on then it all gets dumped. Also the effect of the magnet diminishes on distance from it and is dependent on flow past it.

I completely agree as well that as it won't pick up stainless or non ferrous it's a moot point anyway. How much of your process equipment is made from iron?

Food auditors are used to seeing metal detectors as CCPs in every factory they go to and therefore expect it to be a CCP in yours.

However it is you and your HACCP team that know most about the risks in your factory not an auditor who is only on site for a day or two.

If you can say that there is not a significant risk of metal contamination or metal contamination can be controlled at a previous step then metal detection is not a CCP.

If you are 100% confident in your HACCP and the way the study has been carried out then you should stand up for yourself against the auditors. What your team say is a CCP is a CCP

Because most food machinery is made out of metal then there is a risk of metal contamination which is most usually controlled by metal detectors.


My big question in metal detectors is do they reduce the hazard to an acceptable level?
Do we feel that a 3mm piece of stainless steel is not a hazard?

Interestingly enough I am also a food safety auditor and do not expect metal detection to be a CCP in every facility I go into, even though many manufacturers make it a CCP.

Agreed!


I probably said this earlier but magnets don't necessarily hold on to the contamination depending on how much there is. You can imagine the situation where you get a big load of ferrous come through, stick on then it all gets dumped. Also the effect of the magnet diminishes on distance from it and is dependent on flow past it.

I completely agree as well that as it won't pick up stainless or non ferrous it's a moot point anyway. How much of your process equipment is made from iron?

i work at a rice mill so alot.

i work at a rice mill so alot.

Really? Iron not steel? Why?

Really? Iron not steel? Why?

sorry that my fault it is steel, i meant it that we really don't have that much stainless steel

sorry that my fault it is steel, i meant it that we really don't have that much stainless steel

So it's all mild steel not stainless? Or is it made of another material? Even 'lower' grades of stainless aren't as magnetic as iron. Also there is the incoming product to think about. I would suspect metal contamination from the fields is common?

So it's all mild steel not stainless? Or is it made of another material? Even 'lower' grades of stainless aren't as magnetic as iron. Also there is the incoming product to think about. I would suspect metal contamination from the fields is common?

it mostly all mid grade steel. We definitely get a lot of contamination. But It mostly from the dryers.

GreggC66

Charles, it does not change the product however it does ,if set up correctly , detect the presence of a contaminant , which would then lead to a reject signal. In short it prevents or controls the process in that a decision to release the product , rework the product or reject the product has to be taken . I hope my simplified look at the CCP question has helped. Once it protects the consumer , that's all that counts........

METAL DETECTOR: A Monitoring Activity or a CCP?
Generally, most companies in the food industries today have Metal Detectors in their process lines designed for the purpose of detecting metal hazards. Often this step of the process is considered significantly risky to be classified as a CCP (Critical Control Point) - most food auditors insist it is anyway.

The issue that I am arguing here is that a Metal Detector does not "change the product or ingredients" in shape, by improvements, in aroma, or product enhancement or alterations of any sorts". Instead, all that it does is to alert any presence of ferrous hazards in the product when detected.

And, when ferrous hazards are detected, it is often at the end of the procees line meaning it is way too late hence, rendering the product not safe for public consumption.

The argument here is if a Metal Detector is deemed a CCP, where and what is the CONTROL POINT that support the process step in making food safe or to be safe?

Unlike a sieve which does change the shape of the product or ingredients, why then should we classify a Metal Detector as a Critical Control Point when itself is NOT a Control Point in the Process at all.

If we agree to this line of argument, shouldn't we correctly classify the Metal Detector as simply a monitoring function and as important as it is, be termed as a "Critical Monitoring Step" instead of a "Critical Contol Point / Step" or as I like to term it "Quality Control Point"

As a "Critical Monitoring Step" it would just be a record keeping procedure whilst categorising it as a CCP would certainly attract the auditor's attention and viewed from a more serious angle. (Mind you, calibration remains a requirement anyay you take it)

What is the general consensus? A "Critical Monitoring Step / Quality Control Point"" or a "Critical Control Point" ?

Cheers

Charles Chew