Solving the Problem of Metal Contamination in Food
In a 10 page document, the US Food and Drug Administration (FDA) declares that metal fragments in food may cause dental damage, lacerations of the mouth or throat, or laceration or perforation of the intestine. They do not mention the untold damage to a company’s reputation and the subsequent financial damages. Only last month (February 2017), PetSmart in the USA recalled dog food over a potential metal choking hazard.
It is nearly impossible to stop metal fragments entering a process line. Processing equipment will wear, especially with metal-to-metal contact, and there will be equipment failures (e.g. valves, screens, conveyors, etc.). Once that fact is accepted, then a solution to the problem of removing and detecting that metal before it reaches the consumer can be found.
Several methods of metal removal are employed of which Magnetic Separation and Metal Detection are the most common. The effectiveness of this equipment is dependent on the nature of the product, the location of installation and the maintenance. Well-planned and executed maintenance, especially with planned Magnetic Separator cleaning schedules, will ensure that metal separation levels are maintained for the long term.
Magnetic Separation is commonly used to remove metal from liquids and free flowing solids or powders. By positioning the Magnetic Separator in the process (i.e. inside a pipeline or chute), magnetically susceptible metal (such as ferrous metal and abraded or work hardened stainless steel) is attracted by the magnetic field and then held on the surface of the magnet. There are many different designs of Magnetic Separator and strengths of magnet to suit different applications and locations.
Metal Detection can also be used as part of a separator, whereby metal is detected and then rejected immediately. This is often used in free fall locations, but can result in high losses of product. More commonly, Metal Detection is installed at the end of the process either just before or/and after the product has been packaged and packed.
Guidance to Address Metal Contamination
The FDA document is very helpful and even outlines ways to determine if the potential metal contamination hazard is significant. Continuous monitoring and verification form key parts of the metal contamination management plan. Regular and planned checks on the Magnetic Separators and Metal Detectors are vitally important to ensure that the level of separation and detection performance is maintained over time.
The US Food and Drug Administration (FDA) give specific guidance on the issue of metal inclusion or contamination on their website.
Typical Food Process Line
To assist food manufacturers assess the optimum ways to address metal contamination, we have produced a series of Flow Sheets. These show typical locations for both Magnetic Separators and Metal Detectors.
- Getting Metal out of Chocolate;
- Getting Metal out of Grain and Cereals;
- Getting Metal out of Pet Food;
For more information or a metal contamination site survey by our trained sales engineers, please contact our team on:
Phone: 01442 875081