Preventing Foreign Body Contamination

By Robert Rogers, Senior Adviser of Food Safety and Regulations at Mettler-Toledo Product Inspection

Consumers expect their food and pharmaceuticals to be safe. And rightly so. Among other things, they assume their products include no physical contaminants like metal, glass and stones. While these expectations are more than reasonable, actually ensuring that no foreign materials  get packaged with products is harder than it may appear.

The number one reason to eliminate physical contaminants is of course to protect consumers. The second reason is to avoid costly product recalls. But short of a full-on product recall, word of even one foreign body event can be enough to irreparably damage a brand’s reputation.

The main sources of physical contamination come from raw materials and the manufacturing process itself. The most effective ways to eliminate the chance of contamination is to prevent foreign bodies from entering the product in the first place and to implement a well-designed automated inspection program.

1. Monitor Raw Materials

Foreign bodies introduced along with raw materials at the beginning of the line pose a high risk for a few reasons. Processing might alter the foreign object, such as crushing it into smaller pieces, which makes it more difficult to detect later. Also, a stone, a piece of metal or another hard foreign body can damage processing equipment, leading to downtime, repairs and possibly even more foreign objects coming from the damaged machinery.

It’s important to work with trustworthy raw material suppliers who clearly outline their detection sensitivity standards and ensure the quality of their products.

2. Follow Good Engineering Practices (GEP)

Inherently, small pieces of metal are often produced when installing, repairing and modifying equipment – there is always a risk that those metal pieces and other contaminants might work their way into the product stream. This risk is significantly reduced when a manufacturer follows “Good Engineering Practices” (GEP).

Examples of GEP include performing engineering work, like welding and drilling, outside the production area and into a separate workshop, whenever possible. Workshops should generally be kept clean and tidy, and any equipment repaired there should be thoroughly cleaned before returning to the production floor.

When repairs must be made on the production floor, an enclosed toolbox should be used to hold tools and spare parts. Any piece missing from machinery, such as a nut or bolt, should be accounted for and repaired promptly. Tape or wire should never be used for repairs.

3. Adopt Good Manufacturing Practices (GMP)

Operational consumables like rubber gloves and ear protection, as well as personal effects, present contamination risks, especially if there are sloppy working practices or workers don’t stay hyperaware. “Good Manufacturing Practices” (GMP) are a set of strategies that reduce that risk.

Examples of GMP include banning hair clips and jewelry in the production areas, eliminating paper clips and staples and having no outside pockets on protective clothing. Use only pens, bandages and other ancillary items that are detectable by x-ray systems and/or metal detectors so a lost item is easily found before packaged product leaves the facility.

4. Implement a Preventative Maintenance Program

Despite improvements in modern manufacturing techniques, processes still occasionally break down due to wear and tear. A preventative maintenance program will limit unplanned repairs and reduce the risk of product contamination from malfunctioning equipment.

The degree and frequency of maintenance activities depend on each equipment supplier’s recommendations, the importance of each system on the line and more. Company personnel as well as outside contractors and field-service engineers should work together to maintain the equipment while adhering to established safety standards. All systems should be tested after repairs or maintenance. Promptly report defective machinery and other hazards, and then quickly take any necessary action.

5. Rely on Automated Inspection Systems

Apart from preventing contamination, quality-conscious manufacturers rely on inspection systems that detect foreign bodies and reject contaminated products. Metal detectors and x-ray systems installed on packaging lines are the final safety net.

X-ray systems provide the most thorough product quality monitoring, even at high speeds, and can be used to inspect a wide variety of foods and pharmaceuticals. They excel at identifying dense contaminants including glass, metal, stones, plastics and more, no matter their shape, size or location within the product. X-ray systems are effective even when there is product variation, such as temperature or moisture changes, or when the package includes metal like a foil lid.

When budget is a high priority and metal contamination is the primary concern, metal detectors are a great option. They can inspect bulk and packaged product to detect all types of metal including ferrous, non-ferrous and even stainless steel fragments. Advanced metal detectors use multi-simultaneous frequencies that help discern changes due to the presence of metal versus natural variations within the product.

6. Keep Detailed Records

Records of maintenance, repairs and any contamination incidents should be taken, and all subsequent corrective actions should be recorded. This information is helpful when reviewing the effectiveness of a planned maintenance program and incident resolutions. It also provides evidence that the manufacturer has taken steps to ensure product safety, should a contamination incident with a customer ever occur.

Food and pharmaceutical manufacturers that prevent contamination from occurring, continuously monitor final products for foreign bodies and keep records of activities help ensure the safety of their products. A multifaceted, company-wide program protects consumers, as well as the manufacturer’s customers and brand names.

About the Author

Robert Rogers is the senior adviser of food safety and regulations at Mettler-Toledo Product Inspection.