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Hygienic Design in Food Processing, Part One

Food safety is not only vital when it comes to consumer confidence; the hygienic design of food processing facilities is imperative for the manufacture of safe products. Hygiene control is carefully instilled in the design, construction, and renovation of food & beverage facilities.

The engineers, designers, and other experts at Gray talked at length about how important hygienic design can be to the integrity of the entire operation. To cover this area effectively, we’re breaking it down into a series, this being the first.


Redesign & Renovation: Is it possible to redesign or renovate an existing facility with hygienic design at the forefront?


According to Troy Sandlin, director, A&E integration food & beverage services, “The hygienic design principles for each type of food & beverage facility being renovated will remain the same, but the impact of the renovated space(s) on the existing adjacent spaces within the facility must be considered during the design phase.” Some of the considerations include underground drainage; the pressurization/temperature between the spaces; existing utility systems capacity; and how people/product and the trash generated from production will travel to and from the new space.


The execution of the construction might also need specific attention to those facilities that need to  maintain their operations. If a renovation or expansion project is occurring while the facility is in operation, another level of delicacy and sequencing is required to ensure food safety.


Moreover, the movement of contractors and construction material/trash needs to be planned with the facilities’ operations team to eliminate dust, fumes, and debris from migrating to other areas of the facility, he stressed.  “Providing negative air pressure in the renovated area(s) is one measure that can be taken, as well as temporary wall construction to help mitigate the risk.” Also, utility tie-ins need to be coordinated with the facilities’ operation team to avoid disruption to their existing production.


Speaking from the construction perspective, Paul Kornman, senior project manager, advised “extreme caution” must be taken to make sure product streams, waste streams, and personnel streams are properly addressed, as well as proper evaluation of the product.


Kornman provided a list of questions to be kept top-of-mind:


  • In the general review of hygienic design, can the new process be protected from the decisions and procedures of previous building owners?  “Day one in the facility, the customer has inherited every right and wrong decision made from the beginning of the facility’s existence,” he stated.
  • Can the new process be separated from these areas with new walls and ceilings?
  • Is there a drain layout that lends itself well from preventing standing water from production and clean-up?
  • Does the air move in a manner to push the high hygienic area air to lower hygienic areas and eventually out of the building?
  • Does the site itself offer the food safety requirements to protect the process?
  • How long has water stood in pipes; has microbial growth already started? “Improper details to keep microbial growth from occurring are next to impossible to remedy without completely removing the area where it occurs. That could mean removing an entire wall assembly, slab, and underground plumbing, soils—every facet of the facility carries the risk,” warned Kornman.


Wesley Perkins, senior design manager, stressed the importance of due diligence as critical to assess the condition of the existing facility, utilities, and site. For one, he said, an existing building structural analysis is important, in order to determine its loading capacity. Significant modifications might be required to support such things as new utilities and walkable ceilings. Said Perkins, “While an existing facility might appear to have the applicable infrastructure for your next project, the age and condition of the existing building systems could still require a substantial investment to modify for the new use or replacement entirely.”


As part of the structural analysis, the floor, wall, and roof systems should also be evaluated for areas such as age, condition, and warranties, to estimate the amount of modifications required. Also, lead paint and asbestos, among other existing conditions, should be evaluated and the associated costs of remediation considered.


In addition to the structure itself, Perkins mentioned that the condition of the existing site, surroundings, vegetation—including pest nesting sources—should be part of any evaluation.


If a customer were looking to provide a ready-to-eat product in a new setting, for example, Kornman opined that “selecting a facility that was predominately used for raw processing would be high risk. All associated contaminants from raw protein processing would be expected to be found on ledges, in drains, pipes, among other areas.” As a result, every crevice might present the opportunity to contaminate the ready-to-eat product. “Deliberate demolition, sanitation, and redesign would need to prioritize the mitigation of this risk.”

"Day one in the facility, the customer has inherited every right and wrong decision made from the beginning of the facility’s existence."
Paul Kornman, Senior Project Manager


Keeping it Cool


Another consideration to selecting a facility to renovate is process cooling use. Said Kornman, “If the previous facility had no refrigeration needs, it is likely that the structure is not built to handle the loads that process refrigeration would require.”


A full evaluation of the structure, as well as the addition of reinforcing columns, beams, and joists, would be required to carry the additional roof and underhung ceiling loads. “Additional structure,” Kornman stressed, “can create additional levels of hygiene separation requirements if the structure has an opportunity to be exposed to product.”


Timing is also all-important and should be product-specific. “I would think a raw poultry process moving into a former poultry processing facility would have a less time-consuming turnaround than a frozen chicken process moving into the same building,” concluded Kornman.


Choose Partners Wisely


The importance of choosing the right design-build partner cannot be overstressed. Said Perkins, “Similar to purchasing an existing home, existing facilities should be thoroughly evaluated by qualified, experienced, and trusted partners.”


Turnaround time for the design is also key. Gray’s turnkey design-build approach, for example, allows multiple teams to work concurrently toward project execution. While existing conditions are being assessed, design teams work with the customer to develop preliminary layouts within the existing facility. Therefore, depending on the size and scale of a project, conceptual design and rough order of magnitude pricing could be established within 1-2 months.

"Similar to purchasing an existing home, existing facilities should be thoroughly evaluated by qualified, experienced, and trusted partners."
Wesley Perkins, Senior Design Manager


Airflow & Infrastructure to Prevent Contamination


Airflow management in food & beverage processing facilities is one of the key metrics in maintaining a hygienic production space. Airflow, and the quality of that air, can directly and indirectly help maintain a food-safe environment—as well as the product quality requirements for food & beverage production facilities.


Airflow is used to control a variety of factors in F&B processing plants. These can include temperature and humidity control, room and facility pressurization, ventilation of outdoor air, sanitation and purge cycles, and refrigeration compressor room ventilation (which includes continuous, temperature control, and emergency exhaust with makeup air).


Said Brian Hafendorfer, PE, refrigeration engineer, “Room and facility pressurization, as well as airflow direction in processing spaces, are used to control and prevent contamination of products by moving air from the cleanest space or zone to less clean spaces. Controlling temperature and humidity in spaces can prevent the growth of microbiologicals, preserve food quality, and maintain desired food shelf life.”


Other considerations for airflow direction involve keeping personnel safe from infections that might be spread from person to person, such as COVID-19.  “Inhabited indoor spaces require fresh, outdoor air ventilation to maintain acceptable indoor air quality due to indoor generated contaminants,” Hafendorfer continued. “Ensuring the outdoor air is sufficiently cleaned and free of outdoor containment sources is also an important consideration.”


Often, food & beverage processing facilities will have regularly scheduled sanitation cycles to remove potential microbes whether they are foodborne, people-generated, or introduced from some other source. “Flushing the space with fresh, clean, and dry air helps to return to space to production ready in a shorter time frame,” he averred.


In the end, though, none of these interventions and precautions would make much of a difference if the building design, structure, and mechanical integrity were not up to a gold standard. Material selection for all surfaces is especially important in food & beverage operations to prevent corrosion or potential harboring locations for microbiologicals. Hafendorfer warned: “Doors, as well as how people move through facilities, is another aspect that is designed and controlled to maintain the highest quality facility to deliver the desired food quality and safety.”

"Controlling temperature and humidity in spaces can prevent the growth of microbiologicals, preserve food quality, and maintain desired food shelf life," says Brian Hafendorfer, PE, refrigeration engineer, at Gray.

Stay tuned to learn more about how hygienic design can help combat product contamination, as well as prevent pests and microbial “niches” in Part 2 of this series. We also delve into possible chemical contamination and how COVID-19 has impacted the F&B industry’s efforts to use hygienically designed factories.

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