Components in a Pathogen Environmental Monitoring Program

Food safety for food manufacturing facilities has changed and evolved greatly in the last few decades. A large part of that change involved moving toward a more preventive food safety strategy. The application of hazard analysis has shifted the emphasis from finished product testing to more proactive approaches such as the use of validated critical control points with science-based critical limits to consistently reduce risk. In conjunction with this there has been an increased use of environmental monitoring as a means of verification of the prerequisite programs that serve as the foundation for Hazard Analysis and Critical Control Points (HACCP). Today many facilities are adding or strengthening their pathogen environmental monitoring programs (PEMPs) to enhance their food safety risk reduction efforts.

The two most common types of PEMP are Listeria spp. monitoring as an indicator for Listeria monocytogenes and Salmonella monitoring. Monitoring programs for other pathogens or indicators, such as monitoring for Cronobacter sakazakii in infant formula manufacturing facilities, share many similarities with the PEMPs discussed here. Monitoring for more generic indicator groups, such as sampling for total aerobic bacteria to verify sanitation, differs from the PEMPs discussed in this article. For food manufacturing facilities where there is a science-based reason for a PEMP, there are some common components that should be built into the PEMP to make the program as effective as possible.

Management Commitment

The first component of an effective PEMP is management commitment. Corporate and facility leadership need to understand and support this program and supply appropriate resources and recognition to ensure that it is viewed as an important part of the food safety culture for the organization. These programs can involve significant cost and major implications for production. For example, if the PEMP findings indicate an elevated risk for contamination of the finished product, product may need to be placed on hold and tested, or even reprocessed or destroyed. Effective corrective action could require an investment in new equipment, a product reformulation, or an improvement in the facility’s sanitary design. In other words, management commitment means more than agreeing to pay for some lab tests. One never knows what will be found when a diligent environmental search for a potential product adulterant is conducted, so everyone involved must understand the risks and implications of a finding and be willing to support the program before the first swab is taken.

Determination of Need for PEMP

Not every food manufacturing facility needs to have a PEMP. More testing does not necessarily equal more safety. Rather, the judicious use of food safety resources requires interventions and verifications to be targeted to the most appropriate areas for the greatest risk reduction. A thorough risk evaluation should be conducted to lead the food safety team to a determination of whether or not a PEMP is necessary, which organism or indicator group to monitor, and the degree of stringency of the PEMP. Any type of sampling and testing has the potential for “false” results. This is especially true for microbial testing. Therefore, if a product or process can be designed that precludes the need for a PEMP; this option should be carefully balanced with other considerations such as product safety and quality, consumer acceptance, regulatory requirements, and production expense. An example of a process change that could eliminate the need for a PEMP is to eliminate product exposure to the plant environment (hot filling or aseptic filling versus cold or ambient temperature filling) or pasteurization of the product in its final package. Another example is the reformulation of a product or changing distribution from refrigerated to frozen to prevent the growth of L. monocytogenes.

Risk Evaluation

The next component is a complete evaluation of the science-based food safety risk. We have designed a simple decision tree that can be used as a first step to aid in this risk evaluation. This decision tree has been used for hundreds of products in numerous production facilities and has been found to work well for most products/processes. However, it is meant to be used as a tool to assist in completing the risk evaluation and not used to replace a complete evaluation.