Optimizing the Inspection of Powdered and Granulated Products for Contamination

June 23, 2015

6 Min Read
Optimizing the Inspection of Powdered and Granulated Products for Contamination
This Mettler Toledo gravity flow metal detector inspects falling powdered product, and includes ZMFZ (Zero Metal Free Zone) technology that allows installation near metal fittings, etc. that might otherwise cause false readings.

Haunting today’s food manufacturers and processors is the possible recall of a product contaminated with a foreign material––a public event that would be costly not only in the direct costs of recalling the product, but also in lost retailer and consumer confidence and damaged brand image that are difficult to quantify but even more deadly. Rebuilding these assets often requires years of effort and expense.
No one knows this better than Robert Rogers, senior advisor for food safety and regulation, Mettler Toledo Product Inspection Group. He serves as a food safety subject matter expert to various regulatory and industry organizations including the Food and Drug Administration (FDA), Grocery Manufacturers Association (GMA) and the Packaging Machinery Manufacturers Institute (PMMI), and has written numerous articles and blogs about this critical industry issue.
FSMA (the 2011 Food Safety Modernization Act) requires a food manufacturer or processor to create a written food safety plan and then to implement it.
“That plan,” says Rogers, “will include providing for inspecting ingredients, products and packaging at critical points in your processing, and will help you guard against contaminated product leaving your facility and entering the marketplace where it can be subject to recall.
“Creating that plan will be the job of your in-house food safety team; but to implement it, you will be wise to collaborate with experts who understand how, and at what stages in your processing, to inspect for various potential kinds of contamination and remove contaminated product from the production stream.”
The following are five key steps that Rogers recommends to guide you on the pathway to optimizing that inspection protection to ensure product quality and protect your brand.

1. Know the regulations
Regulations today come from many sources: from national and state government bodies, industry standards groups and from demanding individual retailers such as Wal-Mart. Keeping up with these regulations can be a daunting job for one person. Rather than tasking one person with the job, it is advisable to establish a Food Safety task group that will be responsible for becoming familiar with relevant regulations that affect your industry, and with the standards of the GFSI (Global Food Safety Initiative). This will probably be the group that will write your food safety plan.

2. Tailor the inspection to your specific production environment
Many factors determine how and at what point in your processes you most effectively conduct inspections and what equipment you choose for the task. These factors may also determine what type contamination you inspect for at each point. For example, powdered and granulated product processing often involves sieves and screens at various points in the process, to capture contaminants, as well as magnets designed to attract and hold metal contaminants. Inspecting a product upstream of these devices typically involves searching for a variety of foreign contaminants such as metal, stone, glass and high-density plastics. Rogers recommends also placing product inspection sites downstream of these sites that inspect for different contaminants
Sieves and screens, for example, will wear through use and can themselves produce contamination by introducing small wires into the product stream that can be detected only by sophisticated metal detectors. Magnets only attract and hold metal contaminants that are magnetic (which excludes the stainless steel wires commonly found in process screens) and also have the potential to release accumulated contaminants back into the product stream, since they are not securely captured.
Knowing your production environment will also help identify and compensate for other circumstances that can affect inspection equipment.     “Tight spaces, for example,” says Rogers, “can cause a metal detector to be affected by surrounding metal structures, piping, etc.” That will require choosing a metal detector that incorporates advanced technology that eliminates those external effects.

3. Apply HACCP principles
Your operation is unique, and your inspection program should begin with understanding what you are facing. This is best accomplished by putting in place good manufacturing practices, such as those outlined in a Hazard Analysis and Critical Points (HACCP) program. A HACCP program includes seven core principles:
    • Conduct a food safety hazard analysis
    • Identify the Critical Control Points (CCP)
    • Establish critical limits for each CCP
    • Establish CCP monitoring requirements
    • Establish corrective actions
    • Establish record-keeping procedures
    • Establish procedures to verify the system is working as intended

This analysis will give you a firm handle on what contaminants are most likely to occur in your operation, and at what points, as well as integrity risks that may occur, such as missing product, damaged or mislabeled packages and inconsistent fill levels. These events can be as damaging to your brand image as contaminants, and your program should incorporate inspections to detect them.

4. Optimize productivity
Choosing your inspection equipment carefully from among the variety available on the market can dramatically increase your operation’s productivity, and can minimize downtime due to changeovers or system malfunctions. Obviously, you will be best served by a system designed to work with powdered and granular product, and that matches your company’s specific needs.
For example, choose systems that can match the speed of your line, and if you produce or package multiple products, choose a system that can store multiple product inspection parameters in its controls and change over at the touch of a finger on a touch screen. Many inspection systems today are also available with Condition Monitoring capability that can identify adverse trends in the inspection process early and alert maintenance personnel before lines go down.
It is also wise to source all of your inspection equipment from a single manufacturer, if possible, rather than mixing and matching, to simplify system integration. There are also systems that increase productivity by combining more than one inspection in a single machine, such as a combined metal detector and checkweigher. Such systems directly affect overall productivity.

5. Rely on the experts
Finally, remember that you are the expert on your products, but rely on the experts from inspection systems manufacturers for advice on their equipment, where to place it and how to use it. That expertise enables them to customize a system to meet your specific needs.
But Rogers also recommends that you rely on their expertise on food safety regulations and technology. It is critical for their success that they stay current on those topics, and they are happy to share that expertise as part of their service.


“Facing this aspect of your business,” says Rogers, “learning how to ensure the safety of your unique food products and meet the requirements of regulators, can be daunting. These tips can not only shed some light on how to approach the contamination inspection challenge, but also point that there are experts available to face it with you. You do not need to do this alone.”
William Makely has been writing about packaging--including both materials and equipment--for 25 years. He has published more than 500 articles. He can be reached at [email protected] or 630-960-0821.

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