In this issue, Food Safety Magazine introduces a new column that focuses on the science and technology of cleaning, sanitizing and pest control as part of a food processing or foodservice quality assurance and safety program. Topics to be covered throughout the year by industry professionals and experts in The Clean Operation include environmental, air and surface sampling, environmental hygiene monitoring and verification strategies, safe handling of chemicals, sanitation program development and auditing, sanitation training tools, plant and equipment design, and the sanitarian’s role in the food company’s operations.

The hygienic operation of the food processing plant is critical in today’s business climate. The motivations for implementing effective, science-based sanitation programs include the need to achieve regulatory compliance, to provide due diligence defense and to meet the hygienic condition of the plant, which is a prerequisite for the implementation of any Hazard Analysis & Critical Control Points (HACCP) plan. Other important reasons to ensure that sanitation programs are operating properly are to maintain good vendor relationships and to better trace a contamination problem following a product recall or food- borne illness outbreak. The sanitation program also offers the food company a way in which to verify the plant’s ability to operate in hygienic fashion.

Since the sources of contamination in the food plant are many, ranging from people, facilities, equipment, animals, pests, the plant environment and even foods themselves, the development and implementation of the sanitation audit can be an arduous, stress-inducing and time-consuming task (Figure 1). However, the effectiveness of the food company’s sanitation program is a necessary element in building and maintaining your customer’s confidence in your product. Thus, when evaluating and monitoring your company’s sanitation program efficiency, the essential question that should be asked is: Are you meeting both your company’s needs and the needs of your buyers? Customers should not have to redo analysis or testing of your product before that product is used for the larger quality planning of the ingredient. Customers need to be assured that the product purchased is of high quality and will not cause any harm. While your food plant’s or foodservice operation’s needs might be different from the buyer’s needs—for example, your plant must comply with a specific federally mandated microbial plate count standard—keeping in mind the buyer’s needs for a safe, wholesome product up front will serve as a touchstone for monitoring the efficiency of the sanitation program.

The most accepted way to evaluate and monitor sanitation program efficiency is through a food plant hygiene audit. This type of audit is a systematic and independent examination to determine whether cleaning and sanitation activities are being carried out as planned and whether the planned activities are suitable for compliance with the HACCP prerequisite programs. Hygienic operations are needed to obtain assurance that the quality management system is working and is indeed capable of delivering safe and wholesome products. The efficiency of the sanitation standard operating procedures (SSOPs) and other prerequisite programs and the HACCP system is generally determined through “audits.” This article will provide an overview of the considerations of the sanitation audit from the auditor’s perspective and the “dos and don’ts” that will lead to better monitoring of sanitation program efficiency—the proof in the pudding, as it were.

First, who audits food plant hygiene? The answer is that it depends on the purpose of the audit. Food company supervisors or management personnel can opt to audit internally, for standards compliance and verification of its own facility or because a vendor requests documentation or verification of SSOPs and HACCP systems before entering into a supply agreement with the plant. The vendor company itself can conduct an audit before it contracts with the processing plant, and of course, regulators will visit the plant to audit for compliance purposes or as result of normal inspections. Finally, the processor can contract with a third-party auditor as a means of assuring vendors that the company has a hygienic operation or may do so at the request of vendors. Whichever type of auditor is actually conducting the evaluation of sanitation program efficiency, it is important to know what types of audits are performed and the way in which an auditor should prepare. There are several types of food plant hygiene audits, and the selection of one of these depends on the purpose of the audit:

• Vetting audit. This typically is conducted when a new partnership is formed or when a customer company is trying to determine what the food company is doing with regard to sanitation and other food safety and quality issues before going into business with that processor. The vendor also may want to conduct a vetting audit in order to compare three or four suppliers, and it should be viewed as an opportunity to show why they should choose your company.

• Monitoring audit. This audit is conducted less frequently, essentially just to make sure that the operation is running hygienically and that HACCP plans are working as designed.

• Troubleshooting audit. This audit is conducted at any time a problem is found in order to find the obvious source of the problem, when and why it occurred. The troubleshooting audit requires much sampling and analysis to identify the source of the trouble and to implement appropriate control measures.

Any of these audits can be conducted by any of the types of auditors listed.

Audits are documented evidence of due diligence, an independent and objective review of the system, verification of system effectiveness, and to maintain confidence in HACCP/food safety assurance system (See “Audit in a Nutshell"). When setting up an audit pro- gram, three elements should be considered: organization, goal-setting and fundamental inspection approaches. During the organizational stage, a complete review of the sanitation program as it exists should be done, including all record-keeping systems and documentation. If the food company is setting up a sanitation self-audit program, an in-house team should be established to conduct audits just as a third-party auditor would. It is helpful to divide the plant into small areas and check one of these areas each week.

The basic goals of the food plant hygiene audit can be determined after a thorough review of existing sanitation activities, followed by a listing of defects by category (i.e., personal hygiene practices and cleaning practices). This will help to determine the weaknesses in the program and increase the opportunity to solve sanitation problems up front.

There are some fundamental policies that should be developed with regard to the auditor conducting the actual inspection (no matter whether in-house personnel or third-party evaluators), which includes, but is not limited to, the following. The auditor should:

• Wear suitable clothing

• Use a flashlight

• Have a notepad and open mind

• Determine the area to be inspected

• Observe employee/in-plant practices

• Record defects noted

• Look at obscure places

• Be constructive, watch details

• Be complete, specific and brief

• Distribute, so immediate action can be taken

• Compliment/recognize good work

• Utilize outside inspection services

In addition, each plant and each line should have its own customized audit checklist that will aid in determining and documenting the acceptability/nonacceptability for the following items:

• Receiving area (odor, color, appearance, temperature, statistical process control)

• General plant area (floors, walls, drains, pumps, brushes/pads, foot-baths)

• Processing (tanks/silos, pumps/valves, vacuum breakers, retort charts, pasteurizer charts)

• Employee practices (illness/open lesions, jewelry, restricted areas, foot baths, use of hand tools/utensils, training programs)

• Outer premises and grounds (pest control, housekeeping, roof, doors/ windows, air handling system, building)

• Third-party audits (cleaning and sanitation, SSOPs/GMPs, compliance with scheduled sanitation program, violations/corrective actions, score)

Preparing for the sanitation audit involves the review of SSOPs and hygiene plans. The type of plant being audited should be identified and the auditor must be familiar with both the processing aspects of that specific type of food production and the potential or associated contamination problems specific to that process. The auditor should review the documentation and hygiene design prior to arriving at the site.

During the walk-through of the plant, the auditor will note the areas of deficiencies or problems during audit. The plant manager or supervisor should accompany the auditor (whether an in- house evaluator, vendor, regulator or third party) in order to explain existing deficiencies or potential problems and to foster discussion rather than spur an immediate “write-up” of the problem. This “discovery mode” approach is effective in that when the audit report is filed at the end of the day, it isn’t viewed as a surprise by management, which often results in the auditee being put on the defensive rather than in a proactive mode. By allowing management a chance to explain deficiencies during the audit, the priority is more likely to remain effectively dealing with problems.

During the sanitation audit, the auditor must take care to avoid causing cross- contamination. Like the physician’s “do no harm” mandate, the auditor must take care to be unobtrusive, so as not to interfere with the work and processes as they are going on. The auditor must comply with the same Good Manufacturing Practices (GMPs), sanitation rules, regulations and policies that the plant has established for all personnel.

Following the evaluation, an audit report and recommendations are made in order to verify that the sanitation program is working and to identify areas requiring corrective action. A re-audit is necessary only when a serious violation has occurred.

During this process, the following can be audited: material safety data sheets (MSDS) and hazard communications information, such as labeling and controlled access; written instructions for the use of cleaners and sanitizers (chemicals); operational housekeeping; personal hygiene; and pest, rodent and bird control. The review of employee training records with regard to GMPs, SSOPs and HACCP training can also provide insight to the auditor. By looking at what kinds of training is in place, how workers are trained and how frequently, the auditor is better able to assess the adequacy of the company’s training package. Often, a company that has a good training program has a better workforce in that regard and as a result, problems are minimized because personnel have increased awareness of potential problems and how they play a role in reducing the risks associated with those problems.

As a general rule, microbiological monitoring of food contact surfaces and air quality monitoring would not be audited by the sanitation auditor during the walk-through portion of the audit; rather, the auditor would review the testing and analytical records to verify that the sanitation and environmental monitoring program is working. The exception to this would be if the evaluator is conducting an investigational audit, during which swab samples would be collected and provided to the laboratory for further analysis. An exit interview is set up by the auditor with the food plant supervisor or management during which time deficiencies or problems are pointed out and it is determined what kind of correction action is needed. The plant manager can decide who will be responsible to coordinate among involved departments and implement corrective actions.

While we have focused on the food plant hygiene audit here, the “do’s and don’ts” of these types of audits also apply to all audits in general. By keeping these simple ideals in mind, the auditor will be able to provide a good assessment of potential sanitation or food safety problems, as well as a fair evaluation of what aspects of the sanitation program are well applied.

• Do schedule ahead of time. You want to audit the plant when it is operational in a routine or typical fashion, so that the audit closely reflects normal operating procedures. If the audit is not scheduled ahead of time, it will not provide insight into the actual potential problems that might exist.

• Do request and review records. The auditor should request and review plant records in order to adequately prepare for the audit and identify the areas where keen observation is likely needed. In this way, the auditor can identify deficiencies if they exist, as well as areas that appear to be working properly. When reviewing the records, the auditor should pay particular attention to the documentation of corrective actions and customer complaints. If the plant has a lot of returned product and/or customer complaints, something is wrong.

• Do conduct audits with minimum disruption of processing activity. Again, this is why the auditor should schedule ahead of time and come prepared by reviewing the records.

• Do be courteous and objective, firm but fair. Remember, the people working in the plant are working long hours under many types of daily pressures. The function of the audit is to verify that the system is performing the way it should or to find the deficient areas and suggest remedies. The auditor should not take on the role of a policeman, trying to “catch the criminals.”

• Do acknowledge “positive” aspects of processing/operation. In the real world of food manufacture, one would be hard pressed to receive an audit report of any kind to come back with 100% perfect scores in every category. However, the auditor also should try to point out any positive aspects of the program being evaluated, since these are the areas that the company should continue to successfully implement.

The “don’ts” are the antithesis of the “do’s”: Don’t come unannounced; don’t be unprepared; don’t disrupt processing activity; don’t be judgmental and unfair; don’t be hurried or distracted; and don’t forget to conduct an exit briefing.

Anyone in the food industry who has been through the sanitation audit process might rather undergo a root canal, but it is an essential part of any food manufacturing operation. The food company has to keep in mind that the reason for the audit is to meet not only its needs, but the buyers’ needs, as well. When your company is assured that both of these needs are met, you will have the proof of the pudding.

Purnendu C. Vasavada, Ph.D., is professor of food science at University of Wisconsin-River Falls. As an extension specialist in the area of food safety and microbiology, he has worked with rapid methods and been an instructor in programs the world over. Vasavada directs the three-day course, “Current Concepts in Foodborne Pathogen and Rapid Methods and Automation in Food Microbiology,” designed to provide food processors with up-to-date information on rapid methods, testing protocols and technologies most suitable for their operations.

The Audit in a Nutshell

Audits are documented evidence of due diligence, involving an independent and objective review of the system and verification of system effectiveness to maintain confidence in HACCP/food safety assurance system. Here’s a brief checklist of the elements of a well-designed food plant hygiene audit:


• Record review

• Review of facilities

• Review of documentation

• Finding, if noncompliance

• Communication of findings

• Corrective action agenda

• Closing interview and report


• Equipment sanitation

• Plant environment cleaning

• Personal practices (GMPs)

• Written procedures

• Trained employees to execute the program

• Monitoring to verify program efficiency

• Record of deficiency/corrective actions


• Determine frequency of cleaning and sanitation

• Verify effectiveness of sanitation program

• Detect pathogens

• Identify environmental niches of microbial contamination

• Identify needs for special maintenance

• Evaluation of hygienic design

A Mini-Guide to Rapid Methods for Monitoring Sanitation Efficiency

There have been many advances in the area of environmental hygiene and sanitation monitoring as used by the food and beverage processing industry. Some of the most significant developments have been made in the area of rapid methods used to sample equipment surfaces to monitor the efficiency of sanitation procedures in the plant. The advantages of such rapid methods over conventional swabbing followed by standard aerobic plate count techniques are numerous, including—and depending on the component being measured—the near “real time” results provided, increased sensitivity and good reproducibility of such tests, reduced time, labor, training and associated costs, and improved accuracy.
Today, the rapid methods used for sampling equipment surfaces are based on a variety of test formats and techniques that have proven successful in monitoring for sanitation efficiency. The type of method that selected should be based on considerations such as the type of food or beverage being processed and an operation’s individual sanitation system requirements. Here is a brief review of current rapid methods for environmental screening and monitoring for microbial contaminants on surfaces with examples of some of the commercially available tools.

Surface Contact Plates. A good example of this is the RODAC plate, in which the operator touches the equipment to the surface, incubates the plates for 48 hours and then counts the colonies. Petrifilm (3M Microbiology) and Hycheck (Difco) can be used in this way, which will be described further.

With surface contact plates, there is no time or labor required if the plates are pre-prepared. At a cost of approximately $1.35 per plate, these provide fairly accurate results, although results should still be considered estimates since some microbial contaminants do not adhere to agar. These plates are easy to use, but can be difficult to count due to overlapping colonies. They require little or no training, unless the plates must be manually prepared, and are extremely consistent when purchased prepared.

Paddle Method. The Hycheck (Difco) paddle method is an innovative improvement on the conventional swab. The small paddle, containing bacteriological growth medium on both sides, is rubbed onto the surface, incubated for the appropriate time and temperature, and the colonies are enumerated. The Hycheck may be used to conduct total plate, coliform, yeast, mold, psychrotroph and Lactobacillus counts. There is no time or labor required for preparation with this method, its cost is in the mid-range, and although it provides medium accuracy due to the pickup of general indicator bacteria, it offers extremely consistent media preparation. The paddle also is easy to use, with no user training required.

Petrifilm Contact Method (3M Microbiology). Petrifllm is very effective when used to verify sanitation at critical control points involving equipment and other environmental testing. Essentially, the Petrifilm plate can be used as a direct contact or swab contact method to detect microbial contaminants. The user places 1 mL of sterile deionized water on the film, using a template to form a circle, lifts up the film to expose its rehydrated agar surface, presses the agar surface to the equipment, rejoins the top and bottom sheets of the plate, and incubates it at 30°C-37°C for 24 hours. The cost per test is $1.27, which compares favorably against the cost of a standard agar method.

Protein or Carbohydrate Analysis. With these test strip methods, the target surface is sampled and then the sample is exposed to chemicals to achieve detection of environmental surface contaminants. If proteins or carbohydrates are present, a color change occurs on the test strip. The color development is in relation to the concentration of protein or carbohydrate on the surface. These methods can be conducted in “real-time” (3 to 5 minutes). However, it should be noted that these methods are not appropriate for surfaces that are soiled by fat, such as in a meat or poultry processing operation (because of the high concentration of fat in these products that may mask the protein or carbohydrate present on a surface). Among the protein and carbohydrate analytical tools commercially available are Vericleen Carbohydrate and Protein test strips (Charm Sciences) and Hygiena Carbohydrate color test strips.
ATP Bioluminescence. When luciferin/luciferase comes into contact with the biochemical ATP, light is emitted. The amount of light emitted is measured and given in relative light units (RLUs), which are compared to total plate count or are used to determine general cleanliness. This is considered a “real-time” procedure, because results are acquired in one to two minutes. The line can be tested and recleaned before production begins, and one to two days of product do not have to be recalled in the event that microbial contamination is detected.

Some ATP systems come in the form of automated luminometers (Charm Sciences LUM-T, BioControl Lightning, BioTrace Unilite) and some are swab methods (BioTrace Color ATP Swab, 3M QuickSwab) that provide rapid results on-site. Some ATP bioluminescence systems use adenylate kinese present in a sample to recycle phosphate and make ADP back into ATP (Biotrace, AKRAPID).

In general, ATP bioluminescence methods require little to no time and labor for preparation, are very easy to use, and require little to minor training to use, depending on the specific test or instrument. The cost is medium to high, depending on the system, with approximately $2,500 to $7,500 in capital outlay for luminometers, tests and chemicals, and the cost per test is approximately $2.00 to $2.50. Accuracy of readings does depend on the test and chemicals used.

While this has become a popular method for surface monitoring of microbial contaminants in sanitation efforts, there are a few challenges still to be addressed in the food processing plant. Due to high turnover rates and possibly new method intimidation, some companies purchase ATP systems and then never use them. In one instance, it was recommended that a food processor begin using ATP methods to monitor sanitation. Employees at the plant said that they had heard of the technology. Upon searching the lab, three ATP bioluminometers were found that were not being used. The manager said that they did not work. Upon charging, they worked well. They simply needed to be charged. This is a case where a new employee is trained on a new technology, uses it for a time, then leaves his position and goes elsewhere. Another employee is hired and finds the instrument intimidating and doesn’t use it. Another salesperson comes along and sells them another instrument. They become familiar with it, begin to use it, then leave for another position. The cycle continues this way until the company has many instruments of this type, none of which are being used.

Impedance. This well-known technique involves the opposition to flow of an alternating current in a conducting material. As bacteria multiply, they convert large molecules into smaller, more mobile metabolites that change the impedance of the medium. These metabolites increase the conductance and decrease the impedance of the medium. When microbial populations reach 106 to l0 cells/mL, the change in the impedance of the medium is sufficient to be detected by the instrument. At this point, a detection time is noted. The detection time is inversely proportional to total plate count.

The Bactometer (bioMérieux) and the RABIT (Don Whitley Scientific) systems are instruments based on the impedance technique. There is a high initial cost associated with these systems, but a low cost per test ($45,000 to $69,000 initial capital outlay, $0.45 per test). These systems can analyze many times as many samples as conventional methods, at a ratio of 6:1 versus 10:1. They are extremely accurate, there is much less error than plate counting, minimal training required, extremely consistent materials and results can be obtained in two to 12 hours.

Optical Method. The BioSys optical instrument system, which is distributed by BioSys, Remel, and Foss, allows sanitation swabs or sponges to be added directly and without dilution to a pre-filled disposable test vial containing agar and liquid broth. Vials are placed in the automated BioSys instrument, which detects optical changes in the semi-fluid zone that separates the liquid medium containing the sample from the reading area. This color reaction is recorded by a Windows-based system that includes both calibration software and histogram software, which trends and provides statistical information in a graphical format, and the operator can monitor from one to 128-plus samples simultaneously.

The advantages to using the BioSys optical method are that highly accurate results can be obtained in two to 12 hours, and it exhibits much less error than in plate counting. The system can analyze many times as many samples as conventional, again, at a ratio of approximately 6:1 versus 10:1. The system is extremely accurate, there is much less error than plate counting, minimal training required, extremely consistent materials, no electronic drift, and salty or opaque samples can be analyzed. Moreover, although this instrument has a capital cost associated with its purchase, the cost per test (approximately $1.50) is much lower than the cost per test to conduct the standard plate count method.

Scott M. Russell, Ph.D., is Associate Professor in the Department of Poultry Science at the University of Georgia, Athens, GA., where he has conducted research and provided extension services to the poultry industry for the past seven years. His main areas of interest are developing rapid and automated methods for identifying and enumerating pathogenic and spoilage bacteria from foods of animal origin, and identifying methods for eliminating pathogenic and spoilage organisms from poultry during rearing and processing.