Adverse food safety incidents resulting in product loss and market withdrawals present a significant business risk to food manufacturers today. Increasing expectations from consumers and regulatory agencies have propelled food safety to critical importance.
Pathogens present in food products account for a large portion of recalls in the U.S¹. While the source of the contamination often varies across each product category, and may often be unknown, pathogen prevalence in the processing environment may permit contamination from hygienic design constraints in equipment to surrounding surfaces.
Given risks associated with less-than-ideal equipment design, the critical importance of non-daily sanitation tasks with validated cleaning protocols and frequencies, in addition to daily sanitation requirements, has become increasingly recognized.
The master sanitation schedule
A master sanitation schedule (MSS) is often defined as a program of sanitation cleaning activities that occur on a non-daily basis, composed of equipment and infrastructure tasks, termed periodic equipment cleaning (PEC) and periodic infrastructure cleaning (PIC). These non-daily tasks, particularly those associated with equipment, often encompass surfaces that are inaccessible during routine, or daily, cleaning activities.
A risk-based approach in the selection of tasks, along with appropriate frequencies and protocols, is critically important in ensuring optimal hygiene in the processing environment. An example step-by-step process for the development of a master sanitation schedule is illustrated here.
Figure 1 – MSS Development Process
- Step 1. Determine Process Risk. When developing a master sanitation schedule, understanding various risks that may be present in the manufacturing process is critically important. When evaluating risk, key factors to consider include, but are not limited, to the following: cooked status (e.g., raw, ready-to-eat), presence of allergens, and/or product exposure status (i.e., fully packaged, open to environment). Processes that are deemed to be of higher risk, often will have more stringent requirements (e.g., extent, frequency) for non-daily cleaning tasks.
- Step 2. Equipment Hygienic Design Evaluation. As non-daily cleaning tasks are often targeted toward normally inaccessible surfaces, evaluating equipment for hygienic design will assist in determining where additional cleaning may be required. Compliance of equipment to hygienic design principles can be evaluated through the use of an internal company specification document or, alternatively, by utilizing a checklist for hygienic design published by the North American Meat Institute. Non-compliances should then be compiled for further evaluation.
- Step 3. Analyze Identified Non-Compliances for Risk. Each non-compliance identified during the equipment hygienic design review process should be individually evaluated for risk. This more detailed evaluation process should include the previously identified process risk factors, along with consideration given for location of the non-compliance on the equipment. Non-compliances located within product contact zones are of higher risk than those located in non-product contact zones on equipment or in non-equipment zones.
- Step 4. Determine Non-Daily Cleaning Requirements to Control Identified Risks.Where hygienic design non-compliances are deemed to present a potential risk to the process, additional actions should be identified to minimize the potential risk in ongoing manufacturing operations. These additional actions may include component disassembly and cleaning, heat-treatment (i.e., steaming) of equipment, or use of alternative chemicals, amongst other options.
- Step 5. Update Master Sanitation Schedule. Once the evaluation process is completed, the facility master sanitation schedule should be updated to include, at minimum, the following: required task(s) identified in the prior step, reference to sanitation protocol(s), frequencies of cleaning, employee(s) responsible, and other information as deemed appropriate by the facility.
Validation of MSS frequencies and effectiveness
A critical aspect in the development of a master sanitation schedule is ensuring that the selected cleaning frequencies and associated sanitation protocols are appropriate for the given risk, and thus effective in achieving the desired food safety outcomes.
Figure 2 – MSS Validation Process
A robust process for validating these critical aspects of the master sanitation schedule should be implemented and subsequently repeated, as needed, to build confidence in the program. An example step-by-step validation process is illustrated here.
The process typically begins by reviewing the current stated non-daily task frequency in the facility master sanitation schedule and performing the routine (i.e., daily) sanitation requirements. This initial cleaning ensures accurate evaluation of the normally inaccessible surfaces by limiting potential contamination from exterior surfaces.
Next, the selected components for non-daily cleaning are disassembled to expose the normally inaccessible surfaces. An example of a normally inaccessible surface during routine cleaning is shown here.
An example of normally inaccessible surface
Upon exposure of these surfaces by disassembly, but prior to any further cleaning, a visual inspection for hygiene followed by surface sampling (i.e., total plate count [TPC] or Listeria spp. for ready-to-eat areas) is performed. This “pre-cleaning” inspection process is used to determine if the normally inaccessible surface(s) are able to maintain acceptable hygienic conditions between the stated cleaning intervals in the master sanitation schedule, or whether any adjustments are needed. Acceptable limits, such as negative for pathogens or an upper limit for TPC, for the pre-cleaning inspection should be defined prior to undertaking any validation processes and be risk-based.
The disassembled components are then subjected to the sanitation process as defined by a written procedure. Subsequently, a pre-operational (e.g., post-cleaning) inspection is performed to ensure that the written sanitation procedures, along with associated sanitor actions, are sufficient in achieving the desired cleaning outcome. Visual inspection followed by surface sampling methods are commonly utilized in evaluating the sanitation performance.
By incorporating pre-cleaning and post-cleaning inspections, the master sanitation schedule can be optimized to ensure that required non-daily tasks are performed at the appropriate time interval, while ensuring effective cleaning outcomes. Subsequent repetitions of the process will assist in building confidence in the acquired data, solidifying the program elements.
Conclusion
Utilizing key principles of hygienic equipment design to assess where risks may occur, along with proper validation of frequencies and effectiveness of non-daily sanitation tasks, is critical to ensuring pathogen risks are effectively managed. A data-driven, risk-based master sanitation schedule is a fundamental aspect of a mature cleaning program seeking to achieve a high-level of food safety for the manufacturing process.
