What types of metal contaminants are found in the foods we consume?

Posted October 20, 2011 in Metal Detection, Product Inspection

The most commonly found contaminant in the food industry is metal. Metal fragments can often be inadvertently and unintentionally introduced into food products. If these contaminants are not detected, they can become a major safety hazard for consumers, and seriously damage the reputation and status of the business. What’s more these metal fragments can also damage valuable machinery and shut down production lines leading to significant financial losses. Consequently food processors monitor their production lines rigorously using metal detectors to ensure that the product is completely free from metal contamination, and meets all the health and safety regulations of the Food Safety Act.

The assessment and removal of metal contaminants is now standard practice in the food processing industry. The majority of food retailers make metal detection a critical control point requirement in their supplier’s HACCP plans, to ensure that finished products meet established specifications. The principle sources of metal contamination include:

•    Incoming ingredients:  either contaminated during processing, or transportation of the ingredient
•    Processing equipment:  including grinding, the crushing process or general abrasion or vibration leading to a loss of nuts and bolts
•    Inadequate or unsatisfactory quality assessment procedures.

What are the most common sources of metal contamination?

As most food processing equipment is made of metal, there is always a potential risk of metal contamination.  The most common sources of contamination are:
• loose screws
• bolts
• machine parts
• metal bits (copper staples)
• metal tags
• lead shot in meat
• screen wire
• blades

Can metal detectors spot all traces of ferrous and non ferrous metal fragments in food stuffs?

Metal detectors cannot guarantee a metal-free product; however a properly installed and maintained unit, along with robust and reliable metal detection software can largely control metal contamination in food and ensure product quality and integrity. The Metal detection programme should consider:

• Sensitivity - Identify the type of product so a sensitivity standard can be set up for the process.
• Location: a metal detector can be placed within the production line or at the end of the process once the product is packaged. Usually, a metal detector is placed after a size-reduction process that could introduce metal materials.
• Verification: testing of the equipment against standards done by trained personnel to ensure proper metal detector operation.
• Maintenance:  determined by your supplier and carried out by trained personnel.
• Document:  keep records of any metal detected, identify and correct the source of contamination.
• Calibration: conducted by an accredited agency or the manufacturer at determined frequencies to ensure equipment accuracy.