Food Safety Magazine, August/September 2009

be investigated immediately to determine the source. If it is determined that the source is associated with the production equipment, corrective action can be conducted on that equipment to eliminate the source.

The logs should be reviewed periodically for recurring findings, including false alarms and missing information. Recurring appearances of foreign matter originating from the equipment suggest the true source has not been identified or corrected. False alarms are an equally important issue. They point to some type of interference, which will be discussed later. If the false alarms continue, what typically happens is that the sensitivity of the FMD is reduced, which may make it unable to detect some foreign matter. Missing information may point to a lack of investigation by the responsible individuals.

TESTING (continued from page 26)

“Product safety devices have proven to remove
foreign matter from product streams for many
years.”

cause. The problem is that reducing its sensitivity may well cause the FMD to fail to pick up some foreign matter.

Training for operational, quality assurance and maintenance personnel should be ongoing. Annual refresher training for all personnel is needed to keep the program current. Monitoring turnover, especially of maintenance personnel, is important to ensure no knowledge gaps develop.

Training

Training is needed for the equipment operators who will be monitoring the FMD. They need to know how to respond to an alarm, how to properly log the information and what procedures to follow. Whoever will be doing validation and/or verification checks also needs to be trained. They need to know how to properly conduct the checks, how to follow up on failed checks and how to properly log all checks.

Training is also absolutely critical for maintenance personnel. FMDs should be on a preventative maintenance (PM) program as recommended by the manufacturer. Maintenance personnel need to know how to properly conduct the PM, and how to troubleshoot problems. They may need special equipment to diagnose issues, or an outside technician may be brought in. The adjustment controls should be secured so that only authorized personnel can make changes. More advanced training is usually offered by the manufacturer and might be desired to develop in-house expertise.

What often happens if training is not kept up, or if the adjustment controls are not secured, is that plant personnel end up lowering the sensitivity of the FMD in reaction to excessive false alarms and an inability to properly identify the

Interference

Since FMDs are sensitive devices, many things can interfere with how well they work (see sidebar, p. 26).

Manufacturers will dictate a minimum metal-free zone for installation of the device. Since FMDs operate by creating an electromagnetic field, they need a certain space free of any metal that could warp that field and cause the FMD to be less sensitive than it was designed to be. Other installation concerns are the routing of electronic cables. If the cables are too close or are not properly shielded, they may interfere with the device.

Another common source of electrical interference is radios. Maintenance technicians have been observed transmitting on their radios while standing next to an FMD, immediately causing alarms and rejects. Make sure radios are not placed too close to the machine and personnel using radios know to keep their distance.

Vibration is another common form of interference. During installation, care is needed to eliminate or dampen vibration from equipment. Procedures should be developed and personnel trained to ensure they are not causing vibration near the FMD. When vibration-damp-ening pads are used, regular monitoring is needed to ensure they have not been lost during cleaning or maintenance activities.

When troubleshooting excessive false alarms, sources of interference should be

at the top of the list. Here are some questions that can be asked during troubleshooting:

• Have there been any changes to the surrounding equipment or structure recently?

What possible sources of electrical interference are nearby? Has new electrical equipment been installed recently? Was someone using a radio nearby?

• What sources of vibration are nearby? Has something changed? Was equipment being moved nearby? Are all vi-bration-dampening pads in place and in good repair?

• What other activities were occurring nearby during the false alarms ( cleaning, maintenance, construction, etc.)?

Summary

Product safety devices have proven to remove foreign matter from product streams for many years. They protect both production equipment and the consumer. But they are not “install and forget” devices. They need regular monitoring and maintenance to continue functioning as designed. With the proper care, they will provide the food and beverage industry continued removal of foreign material. ;

R. Mark Davis is the manager of sanitation for Quaker-PepsiCo, a position he has held for two years. His 12 years with PepsiCo includes 10 years with the Frito-Lay North America (FLNA) division, where he became certified as one of its Sanitation Division Expert Trainers. He is a member of IAFP and has a B.A. in Communications from the University of Dayton. He can be reached at mark_r_davis@quakeroats.com.