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Hygienic Zoning for Sanitation Preventive Control

Zoning or segregation of food processing areas presents a unique environment for the food processors to identify area of potentially risk for microbiological cross-contamination. The facility design outlines offers risk-based hazard assessment to determine potential sources of contamination, traffic patterns, employee hygienic practices, and suitable preventive control measure for these areas.  The facility designed must allow for separation of the areas of high-risk foods from being exposed to lower-risk foods and raw ingredients including equipment cleaning, laboratories, maintenance, offices, locker rooms, waste collection and disposal, and toilet areas.  In a food processing facility, sanitation zones are classified as Zone 1, Zone 2, zone 3, and Zone 4 based risk assessment of the environment and cleaning regimen in that specific zone. The degree of hygienic zoning depends on several criteria including facility sanitary design, equipment layout, traffic patterns, type of commodity type (s) is being processed, and location of the facility.  Depending on the product and process and the intended consumer the number of hygiene areas established may vary.
For assessing microbiological risk, one must determine if ready-to-eat products can support growth of spoilage microorganisms or pathogens, or their survival. Based on the risk associated, appropriate preventive control measures should be identified to protect the product. A product supporting the growth of pathogenic or spoilage microorganisms will require more protection to prevent foodborne illness and quality issues than a product in which microbes will die off. The barriers may not only be part of the infrastructure but may also be part of the product package itself. A product that is pasteurized in package, aseptically filled, or retorted will be protected by its packaging from potential microbial contamination after the microbial log reduction; therefore, the building may not need to offer as much protection as it will for an RTE product exposed to the environment after the microbial reduction step. The building and infrastructure need to provide the necessary conditions for products to be made in hygienic conditions.
For sanitation purposes, Zone 3 is primarily a dry environment or no food contact zone.  Since Zone 3 is a potential source dirt and dust, which can contaminate equipment seals on motors, gearboxes and bearings, the processing equipment and other non-food contact surfaces in this zone does not need to be protected from high-pressure wash downs. Contamination of seals and bearing can break the lubrication film may lead to seal damage and ingress into the motor.
Zone 2 is a medium-hygiene zone where areas need at least some kind of wash down. In Zone 2, any standard seal is adequate to prevent moisture from coming into the gearbox, and it is always good to use covers in these areas to protect the gearbox. Painted Equipment, machinery and motors wash down may work well in Zone 2. Even a paint-free design can work quite well in these types of applications.
Zone 1 is a high-hygiene or food prep area. These are the areas where the food product is at its most vulnerable and equipment has direct contact with food. Zone 1 areas also create the best opportunity for bacterial contamination and need to be sanitized thoroughly with a regular scheduled cleanings. At the very least, cleanings are completed at every shift change or quite possibly several times each shift.