If a pyramid can theoretically represent a plant’s overall food safety system, then Hazard Analysis and Critical Control Points (HACCP) plans are the tip of that pyramid. It is through HACCP plan development that the investigation of food safety occurs. This science-based system outlines the methods by which hazards are reduced or eliminated. When microbial hazards are identified in a product or a production process, a critical control point (CCP) may be identified or established to reduce or eliminate the hazards. Critical control points require that the processing parameters are determined. The food safety professional’s ability to prove the efficacy work each department performs for a safe food product implemented benefit the entire company, from the foundation up.
While HACCP is the investigation of hazards, the foundation and bulk of the food safety pyramid is represented by day-to-day employee activities that constitute Good Manufacturing Practices (GMPs) and prerequisite programs (Figure 1). If HACCP plan CCPs are scientifically proven effective through scientific studies, GMPs and prerequisite programs, in turn, are scientifically proven to be effective by environmental monitoring programs (EMPs). Environmental monitoring is the scientific justification to management, auditors, clients and employees that the time, money and efforts put forth for uniforms, traffic patterns, hand washing, cleaning, sanitation, sanitary equipment design and supplier monitoring are effective (Table 1). The food safety professional’s ability to prove the efficacy of the sanitation systems benefits the entire food safety program—from the foundation up.
Four Steps to a Great EMP
Environmental monitoring programs have multiple purposes, including:
• To assess if surface cleaning and sanitizing programs are effective to a microbial level
• To determine if implemented GMPs and prerequisite programs are effective at reducing or eliminating cross-contamination
• To assess equipment/utensils for harborage sites
• To assess cleaning frequency needed
The EMP assessment is not a short-term endeavor. It can take up to two years to gather and trend the necessary data to develop a comprehensive plan. It is important to put together a plan that can be implemented in phases to help assess the data as it is gathered (See “Make the Data Count”). Here are four simple steps that correspond to the four purposes of an EMP—a sure-fire recipe for a highly practical approach to ensuring the sanitary condition of your food processing plant.
Step 1: Assess if cleaning and sanitation programs are effective to a microbial level. Knowing whether your sanitation program is actually working efficiently—or not—is critical to assuring safe food production. Sampling method and frequency, test selection, failure rate, air sampling, sampling time and specifications are all elements that should be included in an EMP—and considered in the first step of program development.
Establish sponge sites. The concept of zone sampling, first put forward by Kraft Foods, is widely used as a site development tool because it allows for environmental monitoring to concentrate on the areas where product is most susceptible to cross-contamination (product contact areas), to track product as it traverses through the plant, and to understand where and how product cross-contamination may occur.
Here is a brief outline of the zones, which includes surfaces and equipment that should be considered when selecting sampling sites:
Zone 1: The area in the plant where there are direct product contact surfaces immediately after a microbial reduction step and before packaging. If there is no kill step in the process, Zone 1 is the point at which the product is exposed to the plant equipment until packaging.
• Conveyer belts
Zone 2: This zone comprises non-product contact areas that are adjacent to product contact surfaces.
• Dead spots
• Equipment framework supports
• Drip shields that may drip onto exposed product
• Panel/operator buttons
• Dust on overhead lights
• Weight control data input area
Zone 3: Non-product contact areas within the processing area that are removed or far away from product contact surfaces but could result in cross-contamination.
• Ventilation shafts
• Water line condensate
• Trolleys, forklifts, walk-alongs
• Trash cans
• Rubber seals around doors
• Walls and ceilings
• Under foot baths
Zone 4: The farthest from the production area, this zone includes all non-product contact surfaces outside the processing room.
• Cooler/freezer floors
• Floors in locker rooms
• Loading docks
Sampling. To maintain budgets, take the greatest volume of samples within Zone 1 and the least in Zone 4. However, sample all zones within a monthly period. Samples should initially be taken once per week for one month prior to cleaning to assess baseline microbial load (Table 2).
Tests to conduct. Because they account for larger numbers of bacteria, coliform and aerobic plate counts (APC) are more sensitive than analyses for specific pathogens. For U.S. Department of Agriculture (USDA) regulated meat and poultry plants, Listeria and Salmonella are to be done according to mandates. If pathogens are analyzed, take sponges after cleaning and before sanitizing so that production can commence prior to return of results. Two to four months after this testing has begun, sample in the same locations immediately after cleaning. Samples should be taken weekly if the production line is used every day, bi-weekly to monthly if the line is only used intermittently.
Failure rate. Out-of-specification results are to be expected. The goal is to limit such instances, and track data to establish failure rates and patterns. A reasonable goal for a EMP program is a < 10 failure rate.
Air sampling. Along with zone sampling, air sampling in or surrounding processing areas is to be included in the EMP. Yeast and mold plates (potato dextrose agar or dichloran rose bengal chloramphenicol) are set out for 15 to 45 minutes. Air samplers may also be used as an alternative means of monitoring air quality.
Time of sampling. Some samples must be taken during the cleaning process, which will most likely occur at night during non-production hours. There-fore, it is recommended that cleaning or lab personnel be trained to conduct sampling.
Specifications. Cleaning and sanitizing must be be effective to a microbial level leading to specifications of <10 colony forming units/sponge for coliforms and aerobic plate count. If Listeria and Salmonella tests are conducted, negative results are required (Table 1).
Step 2: Determine if implemented GMPs and prerequisite programs are effective at reducing or eliminating cross-contamination. A food processing operation can establish many proper GMPs and prerequisites but if the measures in these best practices or protocols are not well-implemented the risk of microbial contamination of the product increases dramatically. Step 2 in creating an effective EMP involves setting specifications or baselines for indicator organisms and then verifying them.
General guidelines. The EMP program data will determine if GMPs and prerequisite programs are properly implemented during production. To allow for bacterial accumulation during production, environmental samples should be taken at least three to four hours after the start of production, and should be continued throughout the shift. Later into a production run, samples should be taken and labeled in sequence to determine spots of bacterial collection and concentration.
Set specifications/baseline. One to three months’ worth of sponge data will determine a specification (baseline) for coliforms, aerobic plate counts, coagulase positive Staphylococcus, Listeria and Salmonella. Coliform and coagulase positive Staphylococcus results of <10 CFU/sponge are desired for Zone 1, negative Listeria and Salmonella and varied CFU/sponge for APC depending on the product (Table 1).
Dairies or fermentative products should not test for aerobic plate counts. Samples of employees and heavy hand contact such as packaging areas are sponge sites for coagulase positive. The CFU/sponge will be higher during production than after cleaning and will vary from plant to plant.
Verification of GMPs and Prerequisites. Once baseline values are understood, deviations above baseline data will indicate a failure in the plant’s systems, such as changes in traffic patterns, employees, and cleaning/sanitizing chemicals. Sampling frequency should be increased when test data shows values above baselines (Figure 2). In order to identify deviation points in the system, increase sampling frequency and the number of sampling sites. GMPs and prerequisite programs can then be reevaluated, retrained and re-implemented as necessary.
Step 3: Assess equipment/utensils for harborage sites. The trend toward sanitary equipment design has helped sanitation crews in many processing plants to more effectively clean and sanitize production lines and their components. Equipment and utensils designed to be easy to clean to a microbiological level are made of scratch- and damage-resistant, corrosion-proof materials. These features help reduce the occurrence of niches and harborage points–welcome environments for unwanted microbial contaminants. More often than not, however, food plants operate using a percentage of older equipment and utensils that do not have the benefit of sanitary design. Older equipment, production line components and utensils that come into contact with food should be assessed routinely.
Sampling. Samples should be taken after cleaning and before sanitizing, when equipment is disassembled to its furthest point. The opportunity arises to sample sites within the equipment not normally sampled. Sampling these sites may point to microbial harborage spots unseen by the eye. This requires sampling during the cleaning process. Identified harborage sites can then be incorporated into the EMP on a scheduled basis that will be determined by Step 4.
Specifications. The APC, coliform, yeast and mold specifications are <10 CFU/sponge, and negative/sponge is required for Listeria and Salmonella (Table 1).
Step 4: Assess cleaning frequency needed. The implementation of an EMP may lead to the restructuring of the sanitation and frequency of the cleaning program the plant currently employs. If baseline data show small or no deviations in the days between cleaning and sanitation, these schedules may be extended. Similarly, baseline deviations may indicate the need for more frequent equipment cleaning and sanitation, and/or breakdown.
Stepping Up Food Safety
A properly established environmental monitoring program will increase the understanding of a processing facility’s food safety control systems and confirm that procedures already in place are in fact effective in reducing the risk of microbial contamination of product. Microbial analysis before and during production will provide verification of plant practices, and the expenses associated with training and quality programs will be justified by tracking results and trending data over time. The EMP will create accountability for the facility in terms of employee training; maintenance of effective sanitation programs; establishment of GMP and prerequisite programs; reduction of existing or potential microorganism harborage points; and justification of time, labor and costs of cleaning frequency. By using these four steps to create a solid EMP, the food processor will build a very strong foundation for HACCP excellence and step up the effectiveness of the total food safety system.
Read the sidebar "Make the Data Count"
Kara Baldus joined TRAC Microbiology, Inc. in August 2005. She is involved in HACCP plan development, research experimental design and data analysis. Kara graduated from University of Wisconsin-Madison with a double major in bacteriology and genetics. She has worked in the food industry as a microbiologist for nearly 10 years. During that time she also earned her masters of business administration and total quality graduate certificate from Edgewood College.
Virginia Deibel Ph.D., is the CEO at TRAC Microbiology. Deibel started TRAC while she was in graduate school (she does not recommend this). In 2002, she graduated from the University of Wisconsin-Madison with a Ph.D. in food microbiology and a minor in bacteriology. Deibel has spent 16 years working in microbiological laboratories. At TRAC, she performs third party audits, numerous speaking engagements and specialized consultations. She is a member of the Food Safety Magazine Editorial Advisory Board.
Make the Data Count
As you develop the environmental monitoring program, keep in mind that the goal is to verify that your sanitation measures and systems are actually working. Data collection, trending and analysis are important to optimize the effectiveness and efficiency of sanitation program goals. Here’s two ways to make your data count:
1. Use mobile data collection technology. These hand-held systems provide a powerful way to obtain secure, near real-time data during food
plant production or foodservice operation. These expedite data collection, increase data quality by eliminating operator input error, and can generate reports in minutes. Because mobile data collection units can incorporate historical data, the data collected is easily translated into meaningful information through trending and analysis, making it possible to establish baselines and to identify recurring hot spots and develop preventive actions to address them. And, of course, real-time data means that corrective actions can be taken immediately when problems arise, streamlining compliance goals and the operation’s efficiency.
2. Use automated sampling or monitoring systems. In the food processing plant, this may mean anything from automated air and water samplers
to temperature monitoring units from which data can be easily transferred into a computer database for ease of analysis. For foodservice establishments, automated systems can track personnel handwashing and hygiene or measure the sanitary condition of grills, refrigerators and food-contact surfaces. And in the lab, rapid or automated microbiology and chemistry test instruments provide speed to result, which means faster confirmation that sanitation systems and policies are adequate and working.