How to reduce metal contaminants and mitigate food safety risks

As headline sponsor of the British Retail Consortium (BRC) Food Safety Europe exhibition, hosted in London on 7th February 2017, Fortress regularly speaks candidly about adopting a joined up approach to food quality assurance. Phil emphasizes: "Consumers today are more aware than ever about where their food has come from and how it's being handled right across the supply chain. As a result of new legislation, domestic and foreign food exporters are under greater pressure to adhere to increasingly stringent levels of compliance and third party audits, whilst also having to contend with an ever-changing inspection market."

The US food safety legislation brought about by the FDA's Food Safety Modernization Act (FSMA), enacted in 2011 and now in the enforcement stage, will have a major impact in EU and UK standards. This law shifts the focus of food safety from reacting to contamination incidents to proactively preventing such incidents. According to research issued by the Association for Packaging and Processing Technologies in their August 2016 update report, food safety guidelines issued by the BRC, Safe Quality Food (SQF) and the Global Food Safety Initiative (GSFI) are largely converging towards FSMA.

Although the changes are being driven by US legislation, the continuing globalisation of the food chain means harmonisation of food safety standards will be inevitable. Already, starting January 2017, food companies will be subject to more frequent audits, with both SQF and the FDA completing annual audits to FSMA standards. In terms of deadlines, the compliance dates vary and are staggered based upon the size of a food business. The rules also impact animal feed and for the first time the growing, harvesting, packaging and storage of produce by US and foreign farms.

Notably, the new FSMA law is also impacting the longstanding Hazard Analysis and Critical Control Point (HACCP) principles, which have been superseded by Hazard Analysis and Risk-Based Preventive Controls (HARPC). Phil notes: "The biggest difference in the HARPC standards is that they extend beyond Critical Control Points. Now, food processors are mandated to document all potential product risks, including naturally occurring hazards and anything that might intentionally or unintentionally get introduced to their facility. It also means greater transparency across the entire supply chain."

Counting the cost of a contamination

Any contamination is a food safety issue that can have an incendiary effect on a food company's reputation. With today's social media culture and 24-hour news reporting, a single contamination incident can make national headlines almost instantly. The reputational and financial consequences can be devastating.

Of all the potential contaminants, metal is still the most likely risk in a food processing and packing plant. In the raw ingredient phase, food is exposed to different processes - from cutting meat, filleting fish, grinding spice or mixing dry and wet baking ingredients. Later down the line, you may be packing and cutting larger quantities into more convenient single service portions or preparing ready-cut vegetables - again introducing a possible metal contaminant into the food supply chain.

Calculating the true cost of a food recall is challenging, as no incident is the same as the next. Also, manufacturers need to consider the scale of the recall, how many customers their potentially contaminated product has reached, the stage in which the item is recalled, any fines or penalties incurred, and the drain on resources and business interruption at the production plant.

Supply chain transparency and the speed in which you can publicly pinpoint the source of a metal contaminant are imperative and can minimise the damage to brand reputation. Again, the FSMA legislation is driving the adoption of track-and-trace technologies in the food and beverage sectors. Phil explains: "To facilitate this traceability, a Fortress metal detector system offers secure, automatic logging of information to show that the metal detector is operational and working correctly. This all helps to narrow the time frame during which a problem can go undetected and reducing the amount of suspect products that must be discarded or recalled in case of an incident."

Don't be a metal detector maverick

Phil advises that when considering an investment in metal detectors to consider the most prevalent contaminant risks and fully investigate the long-term service costs and upgrade options. In some applications, it's obvious which type of inspection technology to opt for, since only one of them can reliably detect the contaminants that pose the risk you're trying to mitigate. And always choose a machinery supplier with strong R&D capabilities and experience. He says: "Very often, Fortress is able to upgrade legacy systems with the latest technology, or suggest bespoke systems, like a multi-lane, multi-aperture metal detector unit, that reduces operational costs and is more compact than installing several units. Food factories may also consider installing metal detectors at specific checkpoints along the manufacturing process, as leaving it until the end of the production line could result in high levels of false rejects and unnecessary disposal of good product and packaging."

For the duration of the equipment's lifespan, Fortress offers a guaranteed upgrade path for all Stealth, Phantom and Interceptor models, ensuring compliance with changing retailer Codes of Practice and industry legislation.

Recent advances in metal detection technology mean that systems are now even more sensitive to metal contaminants, as well as being more user friendly, another requisite of the FSMA guidance.

Many factors will determine the theoretical sensitivity of a metal detector. Among them the aperture size (the smaller the aperture, the smaller the piece of metal that can be detected), the type of metal, product effect, and the type and orientation of the contaminant as it passes through the detector.

Reducing the aperture size is widely regarded as the simplest and most effective way to increase metal detector sensitivity. Phil puts this into context: "Because sensitivity is measured at the geometric centre of the aperture, the ratio of the aperture to the size of the product is an essential consideration. Maximum sensitivity occurs when the belt and food item is closest to the edge of the metal detector portal, so, in most cases, it makes sense that the smaller the aperture, the more failsafe your system is."

Frequency settings must also be factored in. While dropping the frequency can enhance your ability to find ferrous metals, it can limit performance when it comes to non-ferrous metals, because the lower end of the frequency is more responsive to magnetic effects of the contamination. By the same token, the reverse happens when taking the frequency higher - you start to limit your ferrous detection capability but enhance non-ferrous detection.

To solve this, Fortress launched the interceptor range in late 2015. Using simultaneous frequency technology, the higher frequency signal can improve detection levels for stainless steel by as much as 100 per cent, as well as performing better on lower density metals like aluminium. The high and low frequencies emitted by the Interceptor machine also help to remove the product effect signals caused by wet and conductive products.

Cut costs without cutting corners

It's also vital to check that any metal detection system is failsafe. For example, if a fault with the reject system means that a contaminant is detected but not rejected, the line should stop automatically until the situation is resolved. Both the detector performance and fail-safe capability should be tested regularly and full records kept to support traceability. Most food manufacturers will test each metal detector at the start and end of the production shift, and then throughout the day at regular intervals, typically hourly.

In recent months, several inspection machinery suppliers have evoked strong industry reactions by implying that the reliability of metal detectors today could enable companies to cut back on the volume of tests, something Phil and the Fortress team cautions against. He says: "Testing metal detectors regularly using realistic production conditions forms an essential part of manufacturing due diligence. Automatic testing offers a repeatable and objective overview, checking that your metal detector is working as it should."

Fortress's system, Halo 2, is an external device that gives manufacturers a true measure of how each metal detector is performing. It automatically generates a signal calibrated to specified sphere sizes, logging the test results to provide a reliable audit trail. Aside from eliminating human error, the time spent running and documenting repetitive tests translates directly into cost savings. Previously just available for gravity, throat and pipeline metal detectors, Fortress's latest Halo release has been adapted to work with a conveyor style metal detector to further reduce operational costs.

Summing up, Phil cautions against short-term thrift when measuring food safety risks and protecting brand equity: "It's important when investing in inspection equipment to look beyond the upfront costs and consider the OEE. Also, base your decision on the most prevalent food safety risks, and be sure that any technical advantage will actually add value."

For more information about metal contamination and food safety please visit www.fortresstechnology.co.uk.