From: Food Quality & Safety magazine, October/November 2013

Eliminate Bugs Where They Live

by Lori Valigra

Eliminate Bugs Where They Live

Despite major advances in plant and equipment design aimed at minimizing places pathogenic and spoilage microorganisms can hide and breed, the sheer volume and speed of food production combined with the unpredictable element of human interactions still leaves room for improvement in reducing microbial presence. Stoking the push toward more effective sanitation is the forthcoming Food Safety Modernization Act (FSMA).

The current approaches being used are broad and include everything from automating sample data collection in order to identify trends and take predictive action, to minimizing potential contact surfaces in heavily used equipment, to improving the fundamentals like handwashing.

“It is a holistic approach that needs to be taken to monitor and control what is going on in plants,” says Tom Dewey, global marketing manager, 3M Food Safety, St. Paul, Minn. “A key part is ‘are we being effective.’ A lot more attention is being paid to recalls now, and there are a lot better ways to test for and identify bugs than there were 10 years ago, as well as to identify problem areas of a plant.”

Data Trending

Hazard Analysis and Critical Control Points (HACCP) standards are a key part of that process, combined with analyzing data from routine adenosine triphosphate (ATP) hygiene monitoring results and tests like chemical concentrations, pH, as well as time, temperature, and humidity measurements, according to Dewey. 3M’s approach is a data trending system called Clean-Trace that can help identify pass, fail, and caution areas in the master sanitation schedule. Clean-Trace software also can analyze test results and provide reports about the cleanliness of a production line over a given time, identify which areas fail sanitation standards most frequently, and which could be hot spots, like high humidity plants where raw meat is turned into cooked meat or other criteria.

“We try to be predictive where we can,” Dewey says. That includes monitoring the effectiveness of sanitizers. Some plants change out the wash chemicals because certain organisms become immune to them, he mentions. One example is a plant that makes dressings and sauces where chemicals are changed because the factory wants to assure the hard-to-reach areas are cleaned as effectively as possible. And while the evolution of the overall effectiveness of chemicals and sanitation has allowed that plant to reach 99.6 percent cleanliness, it still is striving to improve that number, Dewey says.

A lot of oversight is needed for certain industries, so the data collected daily can be used over time to map it to different crews and to look at the concentration of chemical sanitizers used. “Once you look at the data on a trend chart, you can see if you have issues with the weekend crew, for example, or an area where a specific piece of equipment is on the high end [toward possibly failing] but still passing. You can see problem areas,” Dewey explains. For instance, an old piece of equipment that may have micro cracks on it that might foster the growth of microorganisms.

Some of this testing data still is collected by hand, and some of that is merely collected but not turned into information that can be used effectively, he says. The 3M system uses ATP through a consumable test and then a luminometer to read the ATP. That data then is put into the master sanitation schedule.

Dewey says the information can be used effectively at audits and to help meet FSMA requirements. “Every piece of equipment cleaned needs to be signed off on by the people who cleaned it. They can’t start up again unless all of it is done,” he says, noting that some factories can have up to 90 individual sheets of paper printed every night from such testing. The testing also helps with hazard analysis and methodology for managing an adverse event.

“What we’re identifying is the importance of a complete system that provides accurate results to be verified by the customer and has a fast time-to-result,” he says. “Accuracy is most important factor. An Achilles heel can be a moving target in some plants, while others stay awake at night because they can’t find a problem.”

Eliminating the Cracks

One approach to minimizing bacteria and other organisms is to limit the places they can hide. This involves designing conveyor belts, drums, and other pieces of equipment and components that have fewer exposed surfaces, and in some cases, that use smoother metal.

Conveyors in the past were built in such a way that they had many areas where food could catch or water might pool, for example on belts and motors, notes Jim Monaweck, project manager at Walker Custom Sheet Metal in Grand Rapids, Mich. Monaweck, a 40-year veteran in the food processing business, began working on a sanitary and tool-less conveyor about five years ago, and the company has been marketing it for about a year. Monaweck says it can be snapped apart quickly and has fewer exposed parts to accumulate food and germs.

He says conveyors years ago were cleaned with air and then washdowns with hot water and chemicals became popular. Recently, foaming agents were added to the mix. The equipment was then swabbed to see if there were leftover microorganisms. “In the past a lot of sanitation departments would go in and look with flashlights to see if they were clean, but conveyors are dark [areas] that could be harborages,” he says. “They can be an area where food gets trapped or falls off.” The way to get to the hard-to-reach areas is to take them apart completely, but that has been a cumbersome and slow process requiring a mechanic and downtime for the line personnel.

Monaweck figured out a design that he says is quick and easy to disassemble. “It’s designed so every part can be taken off, leaving a frame that is open for sanitation and inspection,” he says. The company’s product, called the W.O.W. (Walker Original Washdown) Conveyor, can be taken apart in minutes versus hours. Machines can be cleaned daily or even several times a day. According to Monaweck, the other advantage is that disassembly doesn’t require the plant mechanic; a regular line worker can take it apart.

While he notes that his company’s conveyor can cost around 15 percent more than conventional conveyors, he says there are savings in sanitation, maintenance, and downtime as well as in the amount of sanitizing chemicals used.

One company that benefited from the improved conveyor system is El Matador, a Michigan-based corn tortilla chip maker. The company states the tool-less conveyor helped it quadruple output while keeping safe sanitation standards.

Bill Stanley, El Matador’s maintenance manager, says in a write-up about his company’s application that the sanitation team performs all of the conveyor disassembly and reassembly in less than 10 minutes compared with 30 minutes for previous conveyors. The company’s sanitation manager, Bill Mourer, adds there also is an overall reduction in food safety risk because it’s easier to remove the belts. The machine has an open, cantilever style and it’s easier to clean areas around bearings and pulley shafts that the company couldn’t clean before.

Monaweck says the equipment design helps reduce plants’ risks to pathogens. It also can help with factories that run allergen and non-allergen food on the same conveyor. “Plants are trying to get ahead of FSMA to prevent issues in the future. They need to pay attention to design and have a greater degree of cleanliness,” he says.

Another area of focus on all types of equipment, including conveyors, is metal finishes. Some metals have microbial coatings. Others have finishes, like the No. 4 stainless steel finish that has short, parallel finishing lines and “looks pretty.” But Monaweck contends that those lines are like scratches that microbes can attach to. “We don’t use it on food-contact surfaces,” he says. “I think in the 21st century we will get away from finishes like No. 4 on the food-contact surface because of the chance of microbes attaching to the finish.” Microbes are less likely to attach to a mirror finish, but he says that’s too expensive to use in the food industry, so there are other smooth finishing alternatives.

Monaweck notes that part of his work is to educate clients about what surfaces work best for their applications. Since more companies are cutting their engineering staff in recent years, it’s more important than ever to educate those staff members who have taken on new responsibilities when it comes to plant sanitation.

Keeping Components Clean

Rollers and drum motors are components of conveyors that also have drawn attention as areas for new hygienic designs. For example, Interroll, a Wilmington, N.C., maker of conveyor rollers and drum motors, has a drum motor design in which the motor, gearbox, and bearings are internal to the tube, improving its hygienic value, comments Tom Dickinson, product manager. He says the company’s products, known as AC Drum motors, have an Ingress Protection Rating of IP-66, meaning they can be washed down at high pressure and protect against particles. In addition, lubrication is done internally using food-grade oil that he says is approved by the FDA.

According to Dickinson, there’s anecdotal information from customers who feel the press-on fit stainless end caps, stainless drum, and stainless surface help eliminate crevices where bacteria can build, and are quicker to clean. “Some believe the reduced bacteria makes the conveyor a more hygienic design, thus reducing the chances of recall due to bacteria spreading on food being conveyed,” he notes. He says the average price of a recall is $20 million to $30 million, so the penalty for not minimizing bacteria is high.

“The challenges have to deal with the spread of bacteria and the methods in washing down a conveyor or system,” Dickinson points out. “Bacteria travel with water.” Interroll motors, he says, have fewer crevices for food to get trapped compared to external gear motors, and if food does get stuck, it can be washed away more easily. Both the end cap that holds the drum motor in place and the drum motor itself were designed with hygiene in mind, he says.

And like the Walker Custom conveyor belt, the Interroll drum motor can be cleaned in less time, in this case one third of the time, so there’s a production cost savings, Dickinson says. Stopping a line for cleaning can mean $60,000 to $70,000 per minute in production, he notes. “Even a fraction of a minute is a big deal.”

Jake Hughes, sales manager for Omega Metalcraft Inc., Suffolk, Va., who is a customer of Interroll, says the internal nature of the drum motor is good for his end users. He builds conveyers for the ready-to-eat environment. “Most conveyors in the field use ball bearings that require grease,” he explains. “But these [Interroll] have a motor and gear box that are sealed, so there’s no harborage points and nothing is exposed to the elements.” According to Hughes, most Listeria is found in food-grade grease that is used to lubricate bearings, and some plants have grease systems that self-lubricate the bearings. He says a prominent poultry processor based in North Carolina uses the sealed drum motors to avoid such grease problems, which have been tied to recalls in the past. The drums, he notes, eliminate most of the crevices and harboring points.

Interroll’s drum motor design can be washed down at high pressure and can protect against particles.
Interroll’s drum motor design can be washed down at high pressure and can protect against particles.

Handwashing Remains Key

While computer and software tools to identify and monitor problem areas and new types of conveyors and other equipment with fewer areas for microorganisms are among the innovative techniques food processors are focusing on to improve sanitation, at times it’s the least common denominator that remains a sticking point, in this case, compliance with proper handwashing methods. Cascades Tissue Group of Waterford, N.Y., is among the companies working to get employees’ hands cleaner both for their own sake and for the safety of the food and equipment they’re handling.

Cascades came up with antibacterial towels that don’t require any changes in routine. “Five seconds with the towels is better than washing hands and air drying,” says Andrew Sheridan, product manager, quoting a University of Westminster study that found air dryers can increase the bacteria count on hands up to 254 percent, whereas paper towels reduced it up to 75 percent.

He says if someone doesn’t wash their hands fully, the dry paper towels, impregnated with benzalkonium chloride, will kill bacteria.

The towels fit in traditional multifold or universal roll containers already in restrooms and near food machines, he says. They also come in a popup box. They run about 15 percent to 20 percent more costly than standard towels, but there are savings when bacteria is kept from spreading to cause a product recall or employee illness.

These towels are only for hands, not surfaces. Sheridan says the antibacterial action in the towels has shown a persistent effect, continuing to kill bacteria even after a person has dried their hands with them. He adds that his company will look for ways to improve the towels, such as adding other ingredients to kill other types of microorganisms. For more information on hand hygiene, see “Handwashing’s Risks and Rewards.”

Valigra is a writer based in Harrison, Maine. Reach her at



Current Issue

Current Issue

February/March 2015

Site Search

Site Navigation