Note: This guest blog is part two of two. Read part one here.

The World Health Organization estimates that 600 million people worldwide fall ill annually after eating contaminated food. The globalization of food production, combined with more complex, lengthier food chains, places even greater responsibility on food producers and handlers to ensure food safety.

The processing of ingredients upstream means that many food processors, especially meat and dairy processors, inspect in liquid form using pipeline systems before inspecting packaged products again using conveyor metal detectors.

Given that these liquid lines are often processing high-protein foods, pipeline metal detectors need to be able to withstand regular high pressurized washdowns to prevent bacteria from accumulating and to stop the spread of foodborne bugs. Updated systems with reduced external surface areas and better access for washdown make it easier for suppliers to maintain strict hygiene standards.


Metal risks

Of all the contaminants, stainless-steel metal is one of the most common. It is also one of the most difficult to find. Although the majority of containers, pipework and food contact equipment is manufactured from either 304- or 316-type austenitic stainless steels, the 300 series is nonmagnetic and is also a poor electrical conductor compared to other metal types.

For items such as meat, dairy and ready meals, a metal detection unit able to address product effect and significantly increase stainless-steel detection is recommended to reduce false rejects and metal contaminant risks.


Inspection options

Food processors can choose between metal detectors or X-ray for their inspection options. The choice in equipment should be based on the most prevalent risk. In most instances, metal remains the most common contaminant. So it makes sense to consider metal detection as a first option.

Cost remains a major reason why food processors choose metal detectors over X-ray, as the latter continues to be far more expensive. In addition, the latest X-ray systems tend to have more trouble detecting smaller particles and low-density metals such as aluminum that metal detectors will easily identify.

Nowadays, metal detectors can inspect products packaged in metalized poly film packaging with a good level of sensitivity. However, pure aluminum foil — for example an oven-ready tray — may prove too challenging. In this instance, a ferrous in foil detector or X-ray may be recommended.   



As new food legislation suggests, traceability will continue to be a key priority. The speed in which a food company can publicly pinpoint the source of a metal contaminant is imperative and can minimize the damage to brand reputation. Food Safety Modernization Act legislation is driving the adoption of track-and-trace technologies in all food and beverage sectors.

Checking that metal detection systems are failsafe forms part of this agenda. 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 with results kept on record to support traceability.

Automatic testing systems are also starting to gain industry acceptance. They are designed to complement manual testing with physical test samples to reduce the labor costs associated with owning a metal detector and improve analysis effectiveness by eliminating human error.


Sharing the food safety responsibility

Being safety-minded isn’t just about mitigating risks and ticking the rule book. Consumers today are more aware than ever about the origins of their food and how it’s being handled across the supply chain. 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.

Although technology and automation play a part, food safety is a shared responsibility. The rules and audits just add an additional layer of protection. By working together, food manufacturers, machinery suppliers, production staff, retailers and consumers can raise the bar on food safety.