Basic Elements of Effective Food Plant Cleaning and Sanitizing
By Rory Redemann
It’s no secret that when the basic elements of good sanitation practices in the food manufacturing environment are consistently, even habitually, applied over time, all of the company’s food safety programs are enhanced. The cleaner the facility and equipment at the outset of every product run, the better the assurance that potential food safety hazards are mitigated or eliminated every time a shift begins and throughout the entire production cycle.
The key to good sanitation practices is to provide training to a wide base of plant employees, which may include personnel outside of the sanitation department. It is important for supporting functions to understand how they enable effective sanitation— for example, timely disassembly of equipment by maintenance staff, end of production housekeeping, and quality inspections all impact sanitation effectiveness—to foster a better understanding of—and therefore, consistent companywide adherence to—the sanitation protocols suited to each plant’s operational and food safety requirements. This cross-departmental knowledge transfer, coupled with continuous monitoring, follow up and reinforcement of best practices within the plant sanitation department, creates a corporate culture of hygiene that can significantly increase the overall effectiveness of the sanitation program. It is not enough to have an educated and dedicated sanitation crew: Their daily efforts to ensure the hygiene of the plant will be to no avail if maintenance personnel are unaware that they should not take tools from raw materials areas into finished product areas, for example, or if plant engineers do not understand the cleaning challenges posed by placement of equipment or drains.
Briefly, the five basic elements of good sanitation are:
• Assessment of environmental factors to develop effective sanitation procedures
• Commitment to continuous improvement of sanitation practices
• Proper application of daily sanitation procedures
• Use of periodic sanitation, (i.e., tear down and heat)
• Verification of effective sanitation
Here, we will review these elements, with special emphasis on the seven steps to daily sanitation procedures to illustrate the type of practical information that can be incorporated into training programs for all plant employees and managers.
Factoring In Success
There are two general environmental factors that impinge on the development of effective sanitation procedures in the food processing facility: staffing and room/equipment. Missed work due to scheduled vacations and unscheduled personal days make the necessity for a flexible workforce a must. Most processing plants have a variety of complex equipment operated by the plant’s sanitation professionals, and therefore, it is not uncommon to expect employees to rotate into different assignments as needed. This requires that sanitation supervisors vigilantly maintain good training and documentation systems that will help all sanitation crew members quickly get up and running on the procedures. This also creates an opportunity for staff in operations, quality assurance/control and engineering to regularly participate in sanitation training activities since such training might be offered more frequently given the third shift dynamic.
Second, assessment of the production area and equipment is required to hone in on the specific cleaning and sanitizing methods that will need to be applied in order to achieve effective sanitary conditions for the processing of food in a given facility. A good way to ensure that the critical elements of the sanitation process are understood is simply stated in the following
“continuum of control” formula:
Sanitary Design + Effective Sanitation + Traffic Patterns + GMPS + Dry/Uncracked Flooring
In its assessment of sanitation protocols and policies, the sanitation team will want to look at each of the control areas listed in the continuum formula:
• Sanitary design. Does existing machinery and/or new machinery require extensive disassembly? Do construction materials require different cleaning and sanitizing chemicals or methodologies based on age or frequency of use? Are components of new equipment easy to dismantle and reassemble? Are procedural controls manageable or are design changes justified?
• Effectiveness of sanitation procedures. Are limitations known and controls in place? What are the steps included in daily and periodic procedures? Are they being carried out consistently?
• Traffic patterns. Is there separation between raw and ready-to-eat areas, and separation between exposed product areas and packaging, etc.?
• GMPS. Is it difficult to do the wrong thing? For example, an operation can have the best designed equipment but if it is improperly located, the ability of personnel to comply with GMPs will suffer.
• Flooring. Is the infrastructure well maintained?
Each of these areas are necessary to the development of effective sanitation procedures, and when taken together, they provide the basis for building a comprehensive approach to ensuring high standards of hygiene and identifying potential sanitation challenges that will need to be addressed. For example, a typical challenge that might be considered as part of the sanitary design assessment is the reduced visibility in the production room due to a steam fog, which develops as a result of inadequate exhaust via the heating, ventilation and air conditioning (HVAC) system. Clearly, the sanitation staff would benefit from improved visibility in order to thoroughly clean and sanitize equipment and plant surfaces; a foggy room is not conducive to their efforts when the goal is to clean to a microbiological level. but it is difficult to see the equipment and surrounding environment.
Another typical challenge is the inaccessibility of equipment for cleaning and sanitizing. During tear down and reassembly, will the sanitation team be able to get to all the parts, or is the equipment complex and not easily cleanable to a microbiological level? Can the equipment be disassembled without tools, which enables/empowers the sanitation employee and increases effectiveness due to improved ease of the task? If the company expects the sanitation crew to control these components and maintain equipment that is free of biofilms, the equipment itself must be accessible; in other words, they need to see it and scrub it to clean it.
Among other things that can lead to ineffective sanitation—and this list is not all-inclusive—the following should be considered when developing sanitation procedures:
• Aerosols. There is concern in the food processing industry that aerosols are a source of cross-contamination in the food plant environment. Typically, the use of high pressure/low volume water as a tool for cleaning has some level of associated risk because the velocity of the spray can generate aerosols that may migrate organisms from non-food contact surfaces to product-contact surfaces (Figure 1). High pressure water spraying also can drive moisture into and through sealed surfaces, which is not only a concern in terms of functionality but also with regard to the possible development of niches on the equipment that would provide harborage for microorganisms. If possible, high pressure water treatments should be avoided, and employed only in applications that require its use.
In general, it is important to critically assess when and how to properly use high pressure/low volume water. Its use as a cleaning tool should be conducted in a controlled manner to avoid generating aerosols as much as possible. For example, it is recommended that high pressure water spray is not used as a final rinse method because the risk is greater of aerosols migrating from non-product contact surfaces to clean product contact surfaces, essentially negating sanitation efforts.
• Spraying drains and drain components. Drains are high-risk areas for harborage of undesirable microorganisms. Following Good Manufacturing Practices (GMPs) around drains and while handling drain parts helps to ensure they do not impact the surrounding environment. Personnel practices should emphasize how to prevent water from pooling or backing up. Standing water provides an environment in which bacteria can grow and survive. Better assurance is achieved when sanitation personnel who are cleaning food-contact equipment and surfaces are prohibited from also handling drain components.
• Hollow rollers, fixed sleeved assemblies and concave surfaces. It is important to identify these types of components because they will hold moisture, inhibiting the effectiveness of sanitation chemicals and cleaning methods and thus can contribute to the creation of growth environments for microorganisms or the development of biofilms.
• Control buttons, screens and bearings. These are all types of equipment components that often require special cleaning protocols but the details of those cleaning processes are often easily missed because these components are often covered during the cleaning process. It is important to specifically identify a cleaning methodology for these items—before and after covering—to prevent the possibility that they become transfer vehicles for bacteria.
In general, the sanitation process should be documented and sequenced such that protocols can be sustained. This means determining the necessary tasks, when and at what frequency those tasks should happen and in what specific order they should occur in order to ensure that sanitation methods are applied consistently. Again, training is key and should be conducted consistently to prevent erosion of institutional knowledge and thus enhance the proper application of sanitation protocols.
The main objective is to reach and maintain a state of continuous improvement of sanitation practices. In the short term, the sanitation department handles challenges through the implementation of protocols and controls. As an example, sanitation practices involving the element of sanitary equipment design will dictate that equipment is taken apart to the necessary level to ensure that a clean, sanitary state is maintained. Achieving long-term continuous improvement involves improving upon that particular design to make it easy for people to do the right thing. In other words, if a task is difficult to do, the likelihood that it will be done consistently is significantly reduced. The ultimate goal in terms of long-term continuous improvement in this example is to simplify equipment designs so that they have fewer components, have an open design and are easily accessible for cleaning to a microbiological level. Continuous improvement is very important to assuring the effective transfer of knowledge, effective training and ultimately, effective sanitation.
7 Steps of Daily Sanitation
In an effort to institutionalize knowledge and ensure that there is a common foundation in the sanitation processes, our company has identified the following seven steps from which to build specific cleaning requirements for equipment in wet/cleaned processes. Along this vein, it is important to understand that sanitation is a sequence of steps and these build from the successful completion of the previous steps. Sanitation practices are ineffective when steps are not taken in sequence. If there are multiple individuals working in the same area but they are not all working in the same step, the risk of cross-contamination is increased. For example, if one individual in that area is doing a final rinse while another person is doing a pre-rinse and the equipment is adjacent to each other, there is a risk of overspray from the unsanitized surface to the sanitary one. Following daily sanitation steps in sequence and at the same time minimizes such risks.
Step 1: Dry Clean
The dry clean step involves making sure that pre-sanitation tasks are completed consistently. This includes sweeping floors, removing materials, tools, loose or bulk soils and debris from the area to be cleaned, and covering equipment as necessary. In this step, equipment is disassembled to a proper level to provide accessibility for cleaning and sanitizing.
The dry clean is completed before the sanitation crew begins to use water hoses. By removing bulk soil and debris before applying water pressure, the possibility of overspray to adjacent pieces of equipment, walls and floors is greatly diminished. Also, the removal of bulk soil from the area before hosing results in less drain pooling and backups, which poses a potentially high-risk situation.
Step 2: Pre-Rinse
The area and equipment surfaces are rinsed until they are visually free of soils, using the lowest effective pressure to reduce the risk of cross-contamination associated with aerosol migration and overspray. Lower pressure reduces the risk of cross-contamination and machine damage. Although the use of lower pressure/greater volume of water at the appropriate temperature is recommended, there are some operations that deal with soils possessing certain properties that require the use of extra pressure in order to remove them from surfaces. In cases in which the operator must rely on some impingement action generated by higher pressure water spray, it should be done during this step of the daily sanitation process and only at this step.
Step 3: Soap and Scrub
At this point, the walls, floors and equipment should look clean from a distance, given that the majority all of the visible soils have been removed. The essential elements of cleaning—the right detergent at the right concentration, use of mechanical action, the appropriate water temperature and adequate contact time—now come into play. If the equipment surfaces are well prepared for detergent application (i.e., there should be no gross physical soils present or water puddling or standing moisture on the machinery or parts), the full benefit of the cleaning chemical at the correct concentration will be achieved. However, chemicals are not a substitute for mechanical action. Daily scrubbing of product contact surfaces is essential to remove the layer of invisible contaminants that may remain after the application of detergent. (Framework should be scoured weekly, at minimum.) At the same time, adequate contact time between the detergent and the equipment and other surfaces is necessary to achieve a high level of confidence that the cleaning procedure is actually working. If all four of these cleaning parameters are consistently followed, biofilm formation on surfaces is greatly reduced.
Again, the sequence of events, or order of applications, is important. At the soap step, cleaning agents should be applied to the walls and floors first and then applied to the equipment to reduce the potential for cross-contamination and to prevent detergent from drying on equipment surfaces. This sets the stage for effective rinsing at Step 4.
Step 4: Post-Rinse
Again, it is recommended that only the lowest effective pressure and volume of water is used during the post-rinse step to avoid risks associated with aerosols and overspray. As indicated, sanitation personnel should work from walls and floor to equipment, in sequence, to avoid the potential risk of overspray or splashing on equipment that no longer has detergent on it and is considered clean. Similarly, personnel should minimize spraying the floor once rinsing of the equipment begins.
Step 5: Remove and Assemble
At this point, the equipment is clean and GMPs are employed as required. Sanitation personnel will ensure that condensate and standing moisture are removed, as well as any tools utilized during the cleaning process. The crew will conduct pre-operational procedures and sanitize any equipment components that are not accessible once reassembled.
Step 6: Inspect
Pre-operational inspection is provides added assurance that sanitation goals have been achieved in Steps 1 through 5, especially if it involves an existing equipment design that needs to be cycled. If deficiencies are found at this point, they can be corrected; i.e., recleaned by a detergent, rinsed and reinspected.
Step 7: Sanitize
The final daily sanitation step is to sanitize the wall, floor and equipment surfaces. A typical method is to foam walls and floors with the equivalent of 800-1000 parts per million (ppm) of quaternary ammonium as the sanitizing agent (i.e., to an accepted disinfect level). Foam allows the operator to visually confirm good coverage of the sanitizing agent. Walls, floors and the equipment should undergo a flood rinse using a no-rinse contact solution, applied according to the label. The target contact time for equipment is a minimum of 2 minutes, maintaining a detectable sanitizer on that surface. Wall and floor sanitizer should not be diluted prior to a minimum of 10 minutes of contact time.
Periodic Sanitation and Verification
The fourth basic element of an effective cleaning and sanitizing program is periodic sanitation, which involves two practices that, when performed from time to time, provide an added measure of assurance. The first is to periodically tear down equipment for better access. It is a good idea to periodically reevaluate existing equipment from a sanitary design perspective. Do the daily cleaning protocols address all potential risks? Have all potential risks been identified through a sanitary design review? By performing at some frequency a further level of tear down on existing equipment, the operator is able to identify and address any challenge areas, create greater accessibility and verify that there is an effective control in place.
Figure 2 shows the removal of a conveyor to obtain access to the inner sprockets and framework during a periodic sanitation tear down procedure. This approach offers sanitarians the opportunity to manually clean both sides of the conveyor chain. In addition, the chain itself can be placed in a clean-out-of-place (COP) tank for higher concentration and contact time to ensure that there are not potential growth niches in any of the links.
The second periodic sanitation practice is the application of steam or dry heat to equipment at surface temperatures necessary to destroy undesirable microorganisms or potential growth niches. The heat method offers an advantage over chemicals in that the latter only works on surfaces in which they come in contact; if the equipment has cracks or crevices, the chemical is limited in what it will reach and in terms of adequate contact time. With the heat treatment, there is no such limitation. As a guideline, steam heat of 165F for a minimum of 30 minutes and dry heat held at 165F for a minimum of four hours provides a fairly high level of confidence that there has been heat transfer to all components in the targeted area so that all surfaces are maintained at the minimum time-temperature relationship required to destroy microorganisms.
Of course, the effectiveness of the plant’s sanitation practices must be verified to ensure that the production equipment and environment are indeed sanitary. Operators employ many kinds of verification, including physical, organoleptic and visual inspection methods, as part of ongoing environmental hygiene monitoring programs. Microbiological verification methods include many rapid and automated diagnostic screens, test kits and systems that can provide processors with near-real-time indicators about the cleanliness of surfaces, and some of the newer tests can identify target species of organisms. Portable ATP bioluminesence systems are widely used by industry to obtain immediate results about the sanitary or unsanitary condition of food plant surfaces. ATP results are followed up by more in-depth confirmation testing, such as aerobic plate count, which provides results in two to three days.
Creating a Culture of Clean
Ultimately, when sanitation personnel are well informed about the basics of controls for sanitary design limitations, have a solid working knowledge of sanitation GMPs that emphasizes how to limit cross-contamination opportunities and the importance of consistently following established sanitation practices, and receive training on the benefits of continuous assessment and improvement, it is more likely that good adherence to sanitation polices will become the normal mindset in the plant. To ensure that the implementation of good sanitation practices becomes a daily habit among all individuals in the department, management will need to monitor, follow up and introduce some form of reinforcement training schedule. Without these, sanitation initiatives could be viewed as just a program-of-the-month.
On a larger scale, as effective cleaning and sanitizing protocols become habituated, the training can easily be used to train cross-functional staff, such as the QA supervisor or the plant engineer. It is not difficult to introduce this company-wide concept, but it is challenging to have a tangible impact on corporate culture. Increased, yet focused, training of all employees can serve as a way to institutionalize good sanitation practices and thereby advance the company’s food safety goals.
Rory Redemann has been with Kraft for 10 years, the past six years in sanitation. He is a certified Kraft Sanitarian, which includes passing NEHA’s Certified Food Safety Professional exam. His most recent assignment, as USDA Sanitation Programs Leader with the Oscar Mayer/Boca Foods division, involves oversight of USDA sanitation and environmental controls.Categories: Facilities: Sanitation, Food Plant SOPs; Sanitation: Cleaners/Sanitizers, SSOPs