Prove your metal

By Michelle Knott

- Last updated on GMT

Related tags: Metal detector, Hazard analysis and critical control points

Prove your metal
As small firms compete against the big boys for retail business, they have to start using the same food safety systems, as Michelle Knott discovers

Big retailers are increasingly snuggling up to smaller food suppliers as consumers pile on the pressure to provide locally sourced products. This is undoubtedly a great opportunity for many small manufacturers, but being wooed by such powerful and demanding suitors can bring its own problems. Nowhere is this more apparent than in the measures required to prevent foreign body contamination, where some retailers now require every supplier to install a metal detector before they will consider using them.

"The issue of food miles is putting a lot of pressure on food retailers to use smaller, local companies," says Neil Giles, marketing manager for Mettler-Toledo Safeline. "It's great news for small businesses such as artisan bakers and butchers, but they may not like the standards they have to meet."

The main food safety standards, such as the British Retail Consortium's Global Standard or the Global Food Safety Initiative (GFSI) are based on hazard analysis critical control points (HACCP), which involves a systematic assessment of the possible dangers and the measures needed to control them effectively. "There are no massive differences between the big standards regarding foreign body contamination," says Karen Betts, compliance manager for the BRC. "They all require companies to identify any hazards and put measures in place to control them."

In big production operations, installing metal detectors is the obvious, most practical solution. "In a plant bakery you can't see the slicing blades because of safety guards and the volume of bread going through is high, so there is a good argument to say that every plant bakery should have a metal detector," says consultant, Kevin Swoffer.

But controlling the hazard effectively may not always mean investing in new equipment - at least in theory. If, for example, a baker inspects the cutting blades each time a loaf is sliced, they are controlling the risk. "If a loaf is produced in-store and a customer asks to have it sliced it doesn't go through a metal detector, but the baker can see the blades and handles the loaf so there is a control there," says Swoffer.

Nevertheless, the drive to introduce specialised foreign body detection equipment into more food production premises is gaining headway. Version 5 of the BRC's Global Standard came into force on July 1 and the revised wording reveals a subtle change of emphasis, according to Betts.

While issue 4 says the manufacturer should use HACCP to determine the need for a metal detector, version 5 says metal detection equipment should be in place unless the manufacturer can show that it does not need it. "The implication is that you're now more likely to have it than not," says Betts.

Swoffer argues that the effect of the new wording is essentially unchanged: "Ostensibly it's not a change because the outcome is the same. You need to carry out a HACCP analysis and, on the strength of that, decide whether you need to install foreign body detection."

While the industry standards leave a bit of room for manoeuvre, that's still not good enough for some retailers, which insist on metal detectors in every case. "Some retailers have hard and fast rules, and if a buyer wants a higher standard or to do their own thing they can," says Swoffer.

Some small producers are taking this in their stride, while others see it as more of a problem. This is partly to do with the relative risks associated with different production routes and with differences between the products themselves.

For example, according to Swoffer, almost all specialist sausage makers already use metal detectors, because the nature of sausage making means that their products are particularly vulnerable to metal contamination. Not only is there a relatively high risk of contamination from the grinding and mincing operations involved, but sausages are small products so the aperture of a metal detector can afford to be relatively small. This in turn improves the sensitivity of the equipment and makes metal detection a very effective control strategy.

On the other hand, many small cheesemakers believe that other control measures could be more effective for them. "The Specialist Cheesemakers Association (SCA) has reservations about the reliability of metal detectors in cheese production, because the high density of many cheeses makes detection of small pieces of metal difficult. In the case of small cheesemakers, greater emphasis should be placed on prevention of metal contamination in the first place," says the SCA's Clare Cheney.

Some specialists are also concerned that the indiscriminate use of metal detectors does not promote good practice throughout the rest of the production process. "Really, you should be putting control measures in place to ensure the metal detector never goes off. There's a danger that people are looking at control measures the wrong way. You should only really use this kind of product testing for validation," says Swoffer.

In terms of the technology, Giles says that the size of the product and the corresponding detector aperture is just one of many factors that can affect the reliability of metal detectors. "There are so many parameters," he says. "The product makes a big difference, so a detector will be more sensitive for biscuits than for raw meat, for instance."

The type of metal is also important. Ferrous metals are the easiest to spot, followed by non-ferrous. Stainless steel is particularly tricky, which is unfortunate in an industry in which it is used so widely. "You need high-frequency detectors for stainless steel and we're increasingly finding that manufacturers are asking for high-frequency models," says Giles.

With so many factors to consider and a lack of expertise in many smaller firms, vendors are increasingly finding themselves playing the role of consultant, according to Giles: "They come to us saying: 'We only employ 20 people and we've never done metal detection before. Can you help us?' As well as having expertise in terms of the equipment, we're very well versed in the standards for all the major retailers so we can offer a lot of help."

Their changing customer base is also affecting the equipment vendors in other ways. "Ease of use has always been one of the key design features within Safeline, but it's become more important recently as we've been selling to organisations such as small bakers and butchers shops. They want fit-and-forget metal detectors," he says.

For example, a baker may make several types of product, but will not want to adjust the detector between every batch. "We can set the machine up to cluster different products together so it can inspect several products using one setting," says Giles. Another concession to ease of use is to make control menus icon-driven where possible and available in a variety of languages to suit the many migrant workers employed in the food industry.

Cost is always going to be a big concern for small firms and vendors have been driving down the price of entry-level machines. But the cost still remains significant for small firms and uncertainty about the future can be a major barrier against this kind of investment. Suppliers are unwilling to shell out for expensive machinery to meet the demands of a retailer contract that may only last six months.

"That's where hiring and leasing is becoming much more important," says Giles. "Sometimes we'll put in equipment for as little as one month so the supplier can comply with a retailer during a trial period. One large retailer recently placed an order for six machines that they will hire out to small businesses themselves."

For more optimistic manufacturers, future-proofing their investment in the face of possible expansions is a key concern. To meet this demand, Mettler-Toledo Safeline is in the process of introducing a new machine designed to help them start small and build up their foreign body detection capability as their business grows. The Signature Compact S30 system starts as a basic detector/conveyor combo, but allows space for new features to be added as the throughput increases, such as automatic rejection.

One way or another, small firms have to meet the safety standards demanded by retailers if they want to take advantage of the current trend towards local food. According to Swoffer, the key thing is arming themselves with the right know-how. "Many companies need quite a lot of mentoring just to understand the basics of food safety. Some smaller businesses are proficient in HACCP but others lack knowledge," he says.

Swoffer is heavily involved in the BRC-backed Safe and Local Supplier Approval (SALSA) scheme, which aims to make it easier for smaller manufacturers to meet the necessary standards. "SALSA is in the process of developing a very easy-to-read tutorial to do with HACCP. Only a supplier with a good knowledge of HACCP can decide if a hazard is being adequately controlled," he says. FM


  • British Retail Consortium 020 7854 8900
  • Mettler-Toledo Safeline 0870 066 3150
  • SALSA Helpline 01295 724248
  • SCA 020 7253 2114
  • S+S Inspection 01489 553740
  • Kevin Swoffer 01732 849230

Related topics: Food Safety, Hygiene, safety & cleaning

Related products

Listeria Management & Drainage: 5 Essential Steps

Listeria Management & Drainage: 5 Essential Steps

Aco Building Drainage | 26-Apr-2019 | Technical / White Paper

Listeria is widely recognised as a universal problem for food and drink manufacturers. To ensure effective listeria management and control, food and drink...

Hygienic design boosts quality and safety

Hygienic design boosts quality and safety

Minebea Intec | 16-Aug-2018 | Technical / White Paper

Avoiding food contamination and increasing product safety are key objectives of all food producers. It is critical to prevent any type of contamination...


Adulteration versus contamination, protecting our food

Fera Science Ltd. | 30-Oct-2017 | Technical / White Paper

Adulteration affects the confidence of the public as well as business. Meat products are one of the most commonly adulterated foods – we review the challenges...

With a summer of food scares – be better informed

With a summer of food scares – be better informed

Fera Science Ltd. | 23-Oct-2017 | Technical / White Paper

Recalls and supply chain visibility are big issues right now with a summer of food scares - make sure you have the vital tools to ensure your food defence...

Related suppliers

Follow us

Featured Events

View more


View more