True sanitary design for processing equipment encompasses much more than the material used to construct it. Food safety is a critical factor in every stage of food production from processing to packaging for both human food and food produced for companion animals. The FDA’s Food Safety Modernization Act (FSMA) Preventive Controls for Animal Food rule has pushed sanitary processes into the spotlight for pet food and pet treat manufacturers. “Whenever we talk about food safety, we have to incorporate sanitary design,” says Ramon Martinez, director of food safety, Purina, St. Louis, Missouri. “This applies to raw materials and packaging materials, production lines and equipment and finished product.”

This sweeping reform of nationwide standards requires a written food safety plan for sanitation controls that covers procedures, practices and processes to ensure the facility is maintained in a sanitary condition to minimize or prevent hazards. Part of implementing a FSMA-compliant food safety program is recognizing contaminants that can be controlled by an effective prevention-based sanitation process. These FDA rules are shrinking the gap between the sanitary requirements of a human food processing facility and an animal food processing facility. “It’s raised the bar,” says Jim Gaydusek, US and Canada sales manager, Cozzini, LLC, Chicago, Illinois. “The FDA is setting high standards for safe and sanitary pet food processing and all processors will eventually need to meet these new standards.”

While pet food and pet treat processors are ultimately responsible for establishing sanitary procedures and validating those procedures are effective, equipment manufacturers can play a key role by incorporating sanitary design principles into their equipment offerings. A closer look at sanitary design reveals it is more than stainless steel and the benefits go beyond food safety.

A whole new approach

Food safety is the No. 1 priority of any processor. Much of the food processing and packaging equipment in the pet food and treat industry has direct or indirect food-contact surface areas where bacteria can harbor or accidental contamination can occur.

Contamination can come from a variety of sources including organic particles, off-grade product, condensation or other foreign material. “In very simple terms, an important key to better food safety in a processing plant is to design equipment with smooth, impervious, self-draining, and accessible surfaces that minimizes the potential for microbial growth and foreign material, while also facilitating sanitation activities. Additionally, sanitary design and accessibility to all components of the equipment during preventive maintenance will minimize downtime, which will ultimately lead to increased efficiencies and run times from an operational standpoint,” explains Oliver Blome, food safety professional, AIB International, Manhattan, Kansas.

Ten defined principles, referred to as the 10 Commandments of Sanitary Design established by the North American Meat Institute, guide equipment designers on how to build sanitary equipment. (See 10 Principles of Sanitary Design below.) “Sanitary design is a very broad topic, and I think it’s often misunderstood in the food industry,” says Bill Kehrli, vice president of sales and marketing, Cavanna Packaging, Duluth, Georgia. “Sanitary design is not necessarily making something out of stainless steel. Sanitary design doesn’t even require that you use stainless steel. It’s a whole new platform; it’s a whole new start from the very beginning. All the insides are different. Even how we capture chains is different. Equipment designers have to throw out everything they’ve done before from a machine building concept and start with a clean slate. We build sanitary design equipment in mild steel as well as stainless steel and stainless steel washdown depending on the application. Two of the primary principles behind sanitary design is to limit the areas for bacteria to harbor and if you can’t reach it, you can’t clean it.”

“It’s not an inexpensive way to manufacture equipment, but it’s absolutely necessary,” says Keith Shackelford, group vice president of marketing, Middleby Processing and Packaging Technology Brands, Elgin, Illinois. “We’ve always designed the food contact areas to be sanitary and very easy to clean and very robust. It’s the support members like the legs and the framework that really don’t contact the food or the ingredients that are under scrutiny now.”

All areas of the equipment should be open, accessible and easy to clean. That’s a tall order, according to Christian Uebele, engineering manager, Multivac Inc., Kansas City, Missouri. “The sanitary design of the interior of the machine is arguably more important that the exterior. The interior of a machine is harder to clean and inspect, so it is important to eliminate niches or places for product to collect.” Flat surfaces should be rounded or sloped whenever possible. Welds should be full continuous beads. Lap joint frames can’t be touching. They should be stepped off from one another. All areas of the equipment should be readily accessible with no tools required.

Spooner Vicars provides sheeting lines for dog biscuit applications. To eliminate threaded components, they designed special feet so the line height can be adjusted without an expander that requires a threaded nut on the exposed foot. They’ve designed other creative solutions as well, says Gerard Nelson, sales director, Spooner Vicars, Golborne, UK. “If you imagine a sheeting line to make dog biscuits, it’s full of rollers. You have conveyor belts and rollers to drive them. To make it easily accessible, we designed it so the supporting panels rest by gravity and the rollers rest in slots with quick release pins and they can simply be lifted out.”

Even how wires are routed should be addressed. “Traditionally, wires are routed through conduit or metal boxes. True sanitary design principles don’t allow that,” Cavanna’s Kehrli says. “Cables should be accessible to be cleaned, whether it’s a motor or valve, all the way back to the electrical panel every night.”

Rethinking every aspect of a complex machine might seem daunting, but Uebele sees it as an opportunity. “It is an exciting challenge for engineers to eliminate complexity not only to reduce niches and crevices, but to create an assembly that is easier to clean.”

Cleaning protocols are key

How a machine is designed is just one part of the equation for keeping equipment sanitary. Good cleaning processes need to be in place and followed for it to stay sanitary. “Depending on cleaning policies and frequency, a sanitary machine design will allow personnel to be thorough and aggressive in their cleaning practices,” says Ryan Fernholz, regional sales manager, Douglas Machine Inc., Alexandria, Minnesota.

Martinez agrees, “As part of the design, it is important to have the access needed to adequately clean the system to the expectations defined in cleaning validations. It’s much safer for equipment operators when this is considered in the design of the equipment.”

For every type of pet food and pet treat being made there are probably just as many unique cleaning protocols. “The best thing we can do is show processors how to take the machine completely apart 100%,” says Mike Jacko, vice president of applications and new product innovation, Urschel, Chesterton, Indiana. “Manufacturers must have a cleanable machine, a process to clean it and paperwork to verify that it was done. We work with our customers to help them establish their specific sanitary plan.”

The reduced number of components and good access makes sanitary design equipment easier to maintain and service. “Today with 24/7 production, it’s all about small tolerances. If you can improve efficiency by 1% that’s a massive amount when you look at it over a year,” Nelson explains. “If you’re talking about mass production of one product over 24/7, it’s all about the margins. I’ve known of cases where it previously took four people two hours to strip down a machine and change the belts. Now two people can do it in half an hour. Multiply that over 24/7 for a couple of years; that’s a huge savings as well as being much easier for the personnel.”

Open access also has to be balanced with health and safety cautions Gaydusek. “There are safety issues, but companies are addressing that as well. They have review committees that take a look at all of the equipment coming in and they address things like pinch points. They typically follow OSHA’s rules and regulations as far as contact area and distances between moving parts. From what I’ve seen, those issues are being addressed very strongly.”

Every processor has its own unique constraints. Small details can often be overlooked such as how to route cabling and wiring and where the control panel will be located. Nelson says addressing everything that’s in the production room is part of keeping a total environment clean and pathogen free. Martinez agrees, “Sanitary design at Purina certainly applies to our processing equipment, but we also look at the holistic environment that equipment sits in within our factories. Our factories and the equipment used in our processing are all built or purchased according to precise prerequisites to guarantee that the materials, equipment and manufacturing environment —from the floor to ceiling and in between — are all designed to produce safe products.”

If the total environment isn’t designed to handle washdown, different procedures need to be established. Kehrli explains, “Processors don’t necessarily want to bring water into every area because water can be the enemy. Bacteria can grow in water. If the equipment is removable, it can be brought in to a washdown area or a room and washed down more thoroughly with caustic chemicals. We are accommodating certain customers’ limitations. If they don’t have drains in the floors in one area, they can wheel the equipment to another area that does have drains and clean the equipment there.”

Options for existing equipment

Complete redesign from the ground up is best. Although some improvements to existing equipment can help in keeping the equipment more sanitary, modifying an existing design doesn’t quite do the trick according to Kehrli. “Can we make it a little better and easier to clean? Sure, but I wouldn’t put a label on it that says sanitary design. We can improve certain aspects to make equipment  in a processing plant more sanitary, but we can’t say the system follows the 10 commandments.”

Product contact surfaces that have deteriorated can be replaced with more compatible material or catch pans can be added to exposed areas. One of the most common means to increase food safety on older machinery is the use of shields. Proper use of covers and shields can cure many food safety concerns. The downside to this approach is the increased amount of surface area to be sanitized, which slows down the sanitation process.

Newer machines have more channel pathways for product. “You always have to get product in and you always have to get product out,” Jacko explains. “You can put guards on older machines to improve the channel pathways, but guards don’t necessarily make it easier to keep the equipment sanitary. There is always that trade-off and, it’s a difficult decision for companies to make.”

Beyond food safety

Sanitary equipment design has a direct impact on production efficiencies and labor as good design decreases the time to dismantle the equipment for sanitation, maintenance and product changeovers. This translates directly into less downtime and increased production time. “Hygienic equipment design not only mitigates the potential areas prone to harbor bacteria, but it also facilitates post-sanitation evaluation by ensuring accessibility during visual verification and environmental monitoring,” Blome adds.

Producers that have made sanitary design a priority throughout their production can do a more thorough job of cleaning with less people in less time, which equals more opportunity for higher profits with more production. “The savings can be huge,” Kehrli says. “First and foremost, manufacturers know they’re delivering a clean and safe product. Secondly, sanitary design allows them to clean equipment more efficiently. It’s not unheard of to have an 8- or 10-hour cleaning process. If it’s a true sanitary design system, they can probably clean it in half that time with half the people.”

For a larger processor that has gone all in on sanitary design, everything can be fully automated as far as sanitation with clean-in-place systems. This can significantly reduce labor requirements according to Gaydusek. “A manufacturer of super premium kibble that produces 40,000 to 45,000 lbs. per hour can run that whole line with two or three people. It’s the latest thing for the high-end companies. It’s not the same old pet food process.”

Nelson points out another important impact on plant employees that can help processors struggling to maintain a full workforce. “Factories are running equipment very hard all the time. If equipment is quicker to clean and maintain that’s also going to be a major benefit to moral.”

Blurred lines

The requirements for a sanitary environment transcend any distinction between different foods. Cem Yildirim, market development manager, Multivac Inc., Kansas City, Missouri, says, “The standards now expected in pet food and treat production and packaging environments are simply the same standards that have been in place for  generations in the world of protein for consumption by humans. We all gain from sanitary design. The absence or reduction of microbes, which contaminate food for pets or humans, improves safe consumption and limits manufacturers’ risk.”

Jacko has found that companies are willing to spend a little more to make their equipment easier to clean. Whether a plant is producing human food or animal food, the people who are responsible for inspecting processing plants also want to see equipment that is easier to clean because that means the equipment is easier to inspect as well.

“The gain is safe food for our pets, quicker and more thorough cleaning processes and more up-time which translates to a competitive advantage,” Kehrli says. “There is no governing body that certifies equipment meets  sanitary design principles. Processors need to be well educated and self regulated. Look at all the equipment options, talk to the equipment manufacturers, ask about their design principles and most importantly know the characteristics of the product you want to produce and the plan to clean the equipment.”

Martinez concludes, “Sanitary equipment design plays a big role in the safety of both our products and people. It has a positive impact on the entire manufacturing environment. The investment of properly designed equipment makes processes easier, more reliable and more consistent, which can make operations more efficient — both in cost as well as time. Simplified cleaning procedures means less human interaction with the machines, which positively impacts safety, labor and equipment downtime.”

10 principles of sanitary design

Often referred to as the 10 Commandments of Sanitary Design, these principles were created when the North American Meat Institute (NAMI) identified research related to the elimination of Listeria as one of its top priorities in 2001. The resulting Equipment Design Task Force was charged with developing equipment sanitary design principles that met the expectations of the meat and poultry industries. Establishing industry-wide specifications benefits the entire industry by promoting one standard that will help reduce contamination and associated recalls. These principles are appropriate for equipment across all food uses, including pet food and pet treat production.

  1.  Cleanable to a microbiological level to prevent bacterial growth on both product and non-product contact surfaces of the equipment.
  2.  Made of materials compatible with the product, environment and the methods of cleaning and sanitation. 
  3.  Accessible for inspection, maintenance, cleaning and sanitation without the use of tools.
  4.  No product or liquid collection. Equipment should be self-draining.
  5.  Hollow areas should be hermetically sealed. Bolts, mounting plates, brackets and other such items must be continuously welded to the surface not attached via drilled and tapped holes.
  6.  No niches. Equipment parts should be free of niches.
  7.  Sanitary operational performance. Equipment must perform so it does not contribute to unsanitary conditions.
  8.  Hygienic design of maintenance enclosures to ensure food product, water or product liquid does not penetrate or accumulate in and on the enclosure or interface.
  9. Hygienic compatibility with other plant systems such as electrical, hydraulics, steam, air and water.
  10. Validated cleaning and sanitizing protocols must be clearly written, designed and proven effective and efficient.


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