Facility Design Critical to Food Safety

A comprehensive set of standards for sanitary facility design has bolstered the food industry’s ability to fight foodborne pathogens

By Sarah Fister Gale

A few years ago, members from across the food industry did something radical: They set aside competition and worked together to find better ways to battle contamination in food processing facilities. Through a facility-design task force sponsored by the American Meat Institute (AMI), they came together with the common goal of developing a set of standards for the planning, construction and renovation of new and existing facilities, specifically aimed at combating the infiltration and growth of harmful bacteria and pathogens.

The task force included high-profile owners, operators, architects, engineers and contractors, including representatives from Land O’ Frost, Hormel Foods, Kraft, Sara Lee, Bar S, Tyson, McClier, Carter Burgess, Middough Consulting, The Stellar Group, Hendon Redmond, Hixson, Ram Market Solutions, Smithfield and John Morrel.

Bringing together members of industry to define these goals was a revolutionary step for an industry that prides itself on competitive advantage, closely guarding its secret formulas and original recipes.

“We all agreed that food safety would not be used in our industry for competitive advantage,” says Skip Seward, vice president of regulatory affairs for AMI (Washington, DC) and leader of the facility-design task force. “Everyone brought their best practices for sanitary design and their knowledge of where things can and have gone wrong in the past to create a set of principles that will ensure the safety of the production process. It was a remarkable experience.”

Like most industries, meeting with the competition to discuss process strategies initially sounded absurd. But, unlike most industries, food processors see contamination, especially of ready-to-eat products like deli meats or bagged salads, not as an issue of yield or competitive price, but as an issue of safety.

“The difference between food and semiconductors is that, in semi, if you have a contamination incident, the product gets pulled out during quality assurance. If it happens in food, people can die,” says Bob Hunt, a project principal for The Haskell Company, an architectural, engineering and design-build firm in Jacksonville, Florida, and a member of the task force.

Besides being remarkable for bringing competitive brand owners together, the task force was unusual in that it combined the knowledge and experiences of plant owners with the expertise of architects, engineers and contractors, creating a much more in-depth and well-rounded discussion, Seward says. “We wanted a broad approach that would enable us to look at the entire facility and everybody brought something different to the table.”

Owners deal with pathogen problems that occur over the course of many years at their plants, an experience with which contractors and architects are not familiar, while designers and builders undertake dozens of new and retrofit operations every year, making them more aware of the latest tools, technologies and design strategies to combat pathogen problems.

“No single person on the task force had all the expertise,” notes John Butts, vice president of research for Land O’ Frost (Lansing, IL), one of the nations largest producers of deli meats and a member of the task force. “We all learned a lot from each other.”

The sharing of knowledge and need was beneficial to all members of the task force and to the industry as a whole, adds Darryl Wernimont, director of process integration for The Haskell Company (Jacksonville, FL) and a member of the task force. For the first time, owners were sharing stories about what happens years after the architects and builders are gone. With that knowledge, these firms can identify better solutions, giving them a competitive advantage in the field of sanitary facility design and allowing them to better serve the long-term needs of facility operators.

Wernimont found the process to be extremely enlightening from an architectural perspective. “We gained an understanding of the true life cycle of the facility,” he says. “So much happens in the plant that architects never hear about because it happens long after they’re gone.”

By participating in the task force, his group was able to see what problems can arise later on in the life of a plant, such as the development of harborages in surface cracks when walls, floors or ceilings are not sufficiently durable, or the build-up of moisture in walls that are not properly sealed. “When we understand what went wrong in the past, we can make better design decisions to preclude these things in the future.”

The eleven principles

After months of collaboration, the group produced a document called The 11 Principles of Sanitary Facility Design, which was unveiled in 2005 at a workshop sponsored by the AMI Foundation.

Figure 1. Harborages and niches can cause serious contamination issues in food processing applications and should be avoided. Photo courtesy of Hixson.
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The document helps plant owners and plant designers avoid potential contamination problems in food-processing facilities by identifying during the planning phases high-risk areas or issues, such as places where moisture can collect in the plant, harborages and niches that can host pathogen growth, or material and personnel flow that can cause cross-contamination (see Fig. 1).

Along with defining the eleven principles, the task force developed a 107-point questionnaire to define specific criteria associated with each of the sanitary design principles, which designers can use as an audit tool during their planning stages to assess blueprints specifically for food-safety design standards prior to construction.

Nonetheless, there was some skepticism early on about how competing brands could work together toward a common goal. “Going in, we weren’t sure,” Hunt admits. The group knew it couldn’t create specific regulations or set standards that would infringe on proprietary information, so it agreed to take the proprietary nature out of the equation and focus on identifying the problems rather than the solutions.

By focusing on problems, builders and operators can make their own decisions about how and whether they want to deal with certain issues, developing their own proprietary solutions that do not need to be shared with the group, notes Chris Harmon, senior vice president of project management for Hixson, an architectural firm in Cincinnati, and member of the task force.

Figure 2. Shown here, good corridor design. The aisle is wide enough to accommodate sanitation and maintenance activities, as well as movement of materials. Photo courtesy of Hixson.
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“We didn’t want to debate and limit people’s choices,” he says, noting that the principles only offer guidance on important contamination issues (see Fig. 2). For example, the document states that walls need to be durable and impervious to niches, but it leaves it to users to decide how to achieve that goal. “Maybe it’s with stainless-steel wall panels, maybe it’s with a Kynar finish,” Harmon says. “The principles don’t give them the answers, they point them in the right direction.”

Such guidance and framework for assessing risk areas help operators and designers look at their facility plans from a new perspective, launching conversations during the planning process that center on food safety, Seward notes. “It establishes a point of discussion between the company building the facility and the design/architecture firms doing the building. It gives them a forum for their decision-making processes and provides a rationale for certain design decisions.”

Land o’ food safety

Land O’ Frost was one of the first industry members to put the principles into practice, applying them to a new 182,000-square-foot, USDA-approved manufacturing facility in Madisonville, Kentucky, which broke ground in May 2005 and is currently up and running (see Fig. 3). Land O’ Frost designed and built the new facility following the eleven principles, with all design decisions based on sanitary-design concepts.

At the heart of its sanitary-design goals was the creation of a facility that could be kept dry, clean and cold, which meant they would need to strictly control air condensation and create a durable environment free from cracks, harborages, and corners or wells where moisture could get trapped.

“Science tells us that if something gets into a room, if that room is cold and dry, it won’t grow,” says Harmon, adding that in the last five years a much greater emphasis has been put on the dry aspect of that theory. “Everyone knows about cold, but today much more thought is put into the importance of dry conditions.”

Harmon goes so far as to suggest that someday science may show that, in optimally dry conditions, temperature would no longer be an issue, allowing facilities to operate at higher temperatures. “It’s a wild theory, but if it were true, it would change the whole product processing environment.”

In the meantime, the moisture control solution for the Land O’ Frost plant involved adding large, critical air-handling units in high-risk areas of the plant where exposed product would be handled, sliced and packaged. The air-handling units control humidity and dry out the facility after each daily sanitization.

When the facility shifts into clean-up mode, the air-handling units switch from their normal mode to using burners to rapidly heat fresh air and push it into the rooms while sucking the moisture out of the air and exhausting it through the roof. The rooms stay at a high temperature until the moisture conditions are acceptable. At the end of the cleaning shift, the air-handling units switch modes again, using cooling coils to condense the remaining moisture and push cool, dry air into the plant, bringing the temperature back to normal within 20 minutes.

The design team was able to further reduce the risk of moisture build-up in the facility by giving careful attention to the grade and drainage of the floors and surfaces. “Everything had to be self-draining,” Butts explains. “We couldn’t have corners or wall joints where water would pool. It was all sloped with precision.”

New technology makes drying a breeze

New technology is currently being developed to help facilities further improve efforts to reduce moisture by incorporating moisture-absorbing media into air-handling units. Called desiccant-based or desiccant-assisted air-conditioning systems, these cooling units do not need refrigerants and are effective for treating the large humidity loads resulting from ventilation air.

With desiccant systems, in the dehumidification/cooling cycle, the moist return air and some make-up air from outside are filtered and then passed through a slowly rotating, fluted desiccant media wheel, which absorbs moisture. The exiting warm, dry air is then passed through the air-handling unit to be cooled and distributed back to the processing area.

“With desiccant technology, you can keep the room’s relative humidity at 50 percent. That’s very dry,” Harmon says. It also dries the room incredibly fast after cleaning, in some cases reducing drying time by two-thirds, which means less downtime is required for completing sanitation procedures.

The downside, however, is that the technology is currently expensive and consumes an excessive amount of energy, Harmon says, so operators need to carefully consider which rooms would most benefit from these systems.

Although innovations in desiccant technology didn’t result from The 11 Principles, the focus on sanitary facility design has trickled down to material and equipment manufacturers, resulting in new products specifically developed to meet the goals of sanitary facility design, Haskell says. “It’s causing a ripple effect across suppliers.”

Figure 3. An exterior shot of Land O’ Frost’s new 182,000-square-foot, USDA-approved manufacturing facility in Madisonville, Kentucky.
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For example, one of the goals for food-processing operations is to have harborage-free, non-wood doors that can be repeatedly hosed down without damaging electrical components or allowing moisture to be trapped within. That need has sparked a new market and, thus, competitive opportunities in this area.

When The Haskell Company worked on the Land O’ Frost facility, it was a struggle to find a solution for its cold-storage door needs. Since then, two vendors have added non-wood doors to their product lines, says Hunt, and one coating manufacturer is working on a third product to meet surface durability goals for food processors.

The new Land O’ Frost plant also incorporated many existing design strategies, some of which were simply a matter of common sense once the design team looked at it from a food safety standpoint, says Butts. Some examples include eliminating wooden palettes for raw materials and designing a linear flow layout that keeps people, power, water and ingredients away from the high-risk processing spaces where product is open and exposed. “There is complete separation between raw and ready-to-eat products, with no flow-through areas,” Butts says of the design (see Fig. 4).

Figure 4. One of the eleven principles advises maintaining strict physical separations to reduce the likelihood of transfer of hazards from one area to another, as shown here. Image courtesy of The Haskell Company.
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All raw materials brought into the facility travel in identified paths outside of the processing space to eliminate cross-contamination. In the corridors, personnel move from left to right through the plant, also without moving through the processing spaces. Utility corridors are located above double ceilings that are accessed from above, and pipes and wires are dropped vertically into the processing areas, minimizing their exposure. When wiring conduits pass from cold to warm areas, they are wrapped with insulation to prevent temperature variances. The linear configuration also allows for future expansion to the left or right.

Independent stainless-steel drains, square rooms with no dead-air spaces, exposed structures positioned away from walls, and smooth, sealed, cleanable, durable surfaces further contribute to the sanitary design of the facility. All surfaces are coated in a siliconized polyester paint that can endure the harsh cleaning and sanitizing chemicals used in the plant, as well as the extreme heat and radical temperature changes that occur during cleaning, and it won’t chip or break if surfaces are bumped or knocked by heavy equipment. The walls also feature thermal breaks using a curb design at the base with four-inch-thick, insulated, metal-skin wall panels on top to maintain temperature and condensation control between rooms with different temperatures. Metal wall panels were chosen over fiberglass because the latter can buckle during heat changes, making it impossible to waterproof, says Hunt.

Another critical design goal was to eliminate all empty, hidden spaces where moisture could collect unseen and pathogens could settle and grow. “The trick in a large facility is to avoid gaps in walls, ceilings and doors,” Butts says. “That’s something the building industry hasn’t yet embraced, which limits our ability to find solutions.”

Part of achieving that solution, says Butts, is educating subcontractors and workers on the job site not just about what the sanitary design choices are, but also why they are critical. “Some of the criteria in the design are executed in the field. If the contractors don’t understand why they’re doing it, they may make on-site decisions that look good from the outside but could be a time bomb on the inside.”

Butts is urging industry members to expand the education of sanitary design principles to the workers. “It’s so much easier when people understand why we make these choices,” he says.

The 11 Principles for Sanitary Facility Design

Principle 1: Distinct Hygienic Zones Established in the Facility
Maintain strict physical separations that reduce the likelihood of transfer of hazards from one area of the plant, or from one process, to another area of the plant, or process, respectively. Facilitate necessary storage and management of equipment, waste, and temporary clothing to reduce the likelihood of transfer of hazards.

Principle 2: Personnel and Material Flows Controlled to Reduce Hazards

Establish traffic and process flows that control movement of production workers, managers, visitors, QA staff, sanitation and maintenance personnel, products, ingredients, rework, and packaging materials to reduce food safety risks.

Principle 3: Water Accumulation Controlled Inside Facility

Design and construct a building system (floors, walls, ceilings, and supporting infrastructure) that prevents the development and accumulation of water. Ensure that all water positively drains from the process area and that these areas will dry during the allotted time frames.

Principle 4: Room Temperature and Humidity Controlled

Control room temperature and humidity to facilitate control of microbial growth. Keeping process areas cold and dry will reduce the likelihood of growth of potential foodborne pathogens. Ensure that the HVAC/refrigeration systems serving process areas will maintain specified room temperatures and control room-air dew point to prevent condensation. Ensure that control systems include a clean-up purge cycle (heated air make-up and exhaust) to manage fog during sanitation and to dry out the room after sanitation.

Principle 5: Room Airflow and Room Air Quality Controlled

Design, install and maintain HVAC/refrigeration systems serving process areas to ensure airflow will be from more clean to less clean areas, adequately filter air to control contaminants, provide outdoor make-up air to maintain specified airflow, minimize condensation on exposed surfaces, and capture high concentrations of heat, moisture and particulates at their source.

Principle 6: Site Elements Facilitate Sanitary Conditions

Provide site elements such as exterior grounds, lighting, grading, and water management systems to facilitate sanitary conditions for the site. Control access to and from the site.

Principle 7: Building Envelope Facilitates Sanitary Conditions

Design and construct all openings in the building envelope (doors, louvers, fans, and utility penetrations) so that insects and rodents have no harborage around the building perimeter, easy route into the facility, or harborage inside the building. Design and construct envelope components to enable easy cleaning and inspection.

Principle 8: Interior Spatial Design Promotes Sanitation

Provide interior spatial design that enables cleaning, sanitation and maintenance of building components and processing equipment.

Principle 9: Building Components and Construction Facilitate Sanitary Conditions

Design building components to prevent harborage points, ensuring sealed joints and the absence of voids. Facilitate sanitation by using durable materials and isolating utilities with interstitial spaces and stand-offs.

Principle 10: Utility Systems Designed to Prevent Contamination

Design and install utility systems to prevent the introduction of food safety hazards by providing surfaces that are cleanable to a microbiological level, using appropriate construction materials, providing access for cleaning, inspection and maintenance, preventing water collection points, and preventing niches and harborage points.

Principle 11: Sanitation Integrated into Facility Design

Provide proper sanitation systems to eliminate the chemical, physical and microbiological hazards existing in a food plant environment.


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