Environmental Management Programs are not just documents to be written and forgotten, but living systems that require active management.
Environmental monitoring programs (EMPs) are widespread throughout the food, dietary supplement, and animal food industries, as these industries manufacture ready-to-eat (RTE) products. An EMP is a verification activity for a sanitation preventive control. A strong sanitation program will clean and sanitize food-contact and non-food-contact surfaces to remove and kill pathogens. A robust EMP seeks to find the pathogen, followed by intensified sanitation and a root cause investigation. As managers with multiple roles and responsibilities, it is crucial to ensure that your EMP is not just in place, but also effective.
The first part of the article focuses on the first challenge question regarding environmental monitoring programs and how they are unique to a facility.
Challenge No. 1: An EMP is Unique to a Facility
Managing an EMP is a team effort that should be led by the facility. An EMP is a complex program that requires the collective expertise and involvement of a facility team. While corporate may be involved in the initial drafting of an EMP, the facility EMP team should take ownership of its implementation and management.
An EMP is written based on the facility’s blueprint and its flow of foot traffic, wheeled traffic, and ingredients through processing steps. The facility water and air, plumbing, sewage, and trash flow are considered. Designate Zone 3 and Zone 4 areas on the blueprint. Zone 3 areas contain Zones 1 and 2 surfaces, with Zone 1 being food-contact surfaces and Zone 2 being non-food-contact surfaces proximate to Zone 1. If the facility has a kill step and separation of the raw side from the post-kill step side, then areas on the raw side are Zone 4. That makes the majority of the area on the blueprint of most facilities Zone 4. The highest-risk area for environmental pathogen cross-contamination is post-kill step processing, up to the sealing of the primary package. If the facility does not have a kill step (e.g., a blending operation), then Zone 3 areas start with the exposure of opened ingredients to the environment. Zone 3 surfaces tend to be part of the room from ceiling to drains. Zone 2 surfaces are the most difficult to identify and tend to be the parts of equipment below the level of product.
Part of the challenge in writing an EMP is creating the master site list. Once consensus is reached on the zone designations across the facility, the EMP team compiles a list of each site to be swabbed. A small facility may have a total of 100 sites; a large facility may have over 500 sites. Both extremes are rare, and most facilities list closer to 200 sites. There is no “magic number.” Create a list that works for you. The master site list typically notates the area or room, the specific site’s description, and the site’s zone. In addition, many facilities assign a sample site number to simplify the labeling of swab bags and the submission of samples to third-party testing laboratories. Create the master site list on a spreadsheet to sort by zone. When the team reviews the list of sites by zone, there should be a long list from Zone 1 and a short list from Zone 4. The lists from Zones 2 and 3 will be somewhere in the middle for the number of sites.
The next decisions are very challenging. For each of the four lists of sites by zone, what is the frequency of completing the rotation of sampling every site in the zone? The answer is, “it depends.” The frequency will depend on the risk of the product to an environmental pathogen, the control of the pathogen at the facility, the previous positive results in the product, and the facility’s food safety culture, among other considerations. A general rule of thumb is to complete the rotation of sites from Zone 1 within one month and the rotation of sites from Zone 4 quarterly. The rotation of sites from Zones 2 and 3 will be completed within one, two, or three months. If there are ten drains in a Zone 3 area and the rotation is completed quarterly, do you really want to wait another three months to swab a drain when drains are notoriously contaminated? Completing the rotation of sites in Zone 3 within four to eight weeks may be more appropriate for the control of an environmental pathogen. All of this is based on risk, and the general rule may not work at your facility.
The next step is calculating the number of sites to swab from each zone weekly. If there are 100 sites in Zone 1 on the master site list and the rotation is one month, then 25 sites must be swabbed weekly. Include sites from Zone 1 weekly to catch potential problems early. If there are ten sites in Zone 4 and the rotation is quarterly, one or no site can be swabbed weekly, two sites biweekly, or some combination. It is important to note that many facilities have a random number generator to choose the site for sampling. It is more important to ensure that the master site list for each zone is completed within the rotation than to randomize the sampling sites. When a random number generator is solely followed, some sites may be skipped for a long time.
What will happen over time? You will see positive or negative trends as you plot the data and review the results holistically by the quarter, semi-annually, and/or annually. You will identify problem areas like a drain that tests positive occasionally. There may be consistently negative sites that can be dropped from the master site list. More sites tend to be added over time, so it is good to drop some sites, with justification and as appropriate.
Article by: By Kathy Knutson Ph.D., PCQI