Site and facility design is a critical component of petfood safety. The seamless integration of design, systems integration and processing equipment technology minimizes the risks of product contamination.
If the process engineer designs the project independently, iterative redesign often results from scrutiny by the facility owner and others during the design review stage. A more efficient and fail-safe way to achieve a technically sound, food safety solution for petfood manufacturing is through early collaboration among the process engineer, systems integrator and equipment vendor. The careful integration of decisions reached by this trio is key to food safety risk management.
Discussions between the collaborative parties must begin with a clear understanding of the “what, where and how” pertaining to the petfood being processed. To ensure that location and storage of raw materials, movement and handling of the ingredients and processing procedures are performed via contaminant-free methods, preventive controls must be addressed.
Again, collaboration can help determine the controls. For example, a walk-through of the environment from which the raw ingredients are transported can determine what safety practices are in place at that source.
When the raw ingredients arrive at the food processing plant, the proper equipment can test samples before the ingredients are dispensed into storage containers. The type of storage containers and their locations in distinctly separate areas for wet and dry ingredients can eliminate contamination.
When the collaborative expertise of the engineer, integrator and vendor performs a hazard analysis, they can collectively determine ways to prevent, eliminate or reduce the occurrence of any hazards that are likely to occur before, during and after processing. For instance, the strategic placement of sensor and surveillance devices could signal problems well before disaster occurs. Once preventive controls are addressed, next steps can begin with designing the facility layout, installing the right equipment and integrating systems accordingly.
The substances that come in direct contact with processing equipment and the processing line have the greatest potential for contaminating the product. These include incoming air, processed air, fresh water, waste water, production aides, sanitizers and people.
For example, pneumatically operated equipment used to move dry petfood through the processing line can introduce contaminants. If compressed air is drawn from the main air intake of the facility to produce the mechanical motions of the equipment, that air can contain contaminants, including pollen, dust, mold, bacteria, viruses and pesticides. Standard equipment filters cannot remove all these contaminants.
In human food processing, a long-time strategy for sanitation control is positive air pressure systems. These systems create a pressure differential between processing areas and outside spaces that prevents the airborne flow of contaminants to sanitary areas.
However, the process engineer must clearly understand the entire line’s processing to determine how the plant should be zoned for proper airflow and pressurization and whether additions or changes to the placement of fans, ductwork and additional air filtration are needed.
Water is also a critical utility for petfood processing plants. Where there is water, there is humidity, which sticks to every surface, harboring bacterial growth. While some surfaces can be sealed to prevent microbial growth and commercial dehumidifiers can be strategically placed, a more effective solution is to isolate, control or minimize water usage.
For example, a high-pressure water hose is often used to clean extruder dies. An employee might place these dies in a wall sink in the processing area, to wash them, or even worse, on the floor. This would risk contamination to other processing equipment from splashed water and food particles.
One solution is to design a dedicated cleaning room where equipment is removed from the processing area and cleaned in an isolated clean out-of-place (COP) room. The COP room must have appropriate ventilation, wall and floor finishes and equipment including sinks, hoods and drains. This enables an efficient, sanitary cleaning operation.
Alternatively, vacuum systems or pressurized carbon dioxide can be used instead of water. The same cleaning can be accomplished without the potential contamination and cleanup of water-based cleaning.
The design of the entire facility, including the site, contributes to both food safety and cost-effective processing. With site layout, agricultural areas surrounding the facility may add airborne contaminants that impact the location of the main air intakes. Vehicle traffic by visitors, workers and raw material deliveries impact the location of facility entrances. Drainage systems at the facility’s perimeter should eliminate soil saturation, and storm runoff should be routed as far away from the facility as feasible. Seasonal and indigenous animals and insects in the area may contribute to other facility requirements.
Collaboration on optimal process flow, from incoming raw materials to the finished product, is critical. Consider the extrusion equipment. Whereas the process engineer might provide for minimum equipment clearance, discussion with the systems integrator might show that additional space is required to facilitate use of lifting mechanisms for the die, as well as space to maneuver a forklift to move or replace the extruder itself when necessary. Consultation with the equipment vendor might further suggest placing the extruder three stories above the floor to avoid the need for an airlift at the end and where the product could be dropped onto a short conveyor.
When the three experts collaborate on the best solution, multiple site and facility design issues are resolved early and without redesign, layout improvements are detected early in the design phase, and flow efficiency and food safety is greatly improved.
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