[Plant Sanitation] Environmental Monitoring for Non-Pathogenic Organisms

Recommendations for validating the effectiveness of your plant’s sanitation program to prevent product contamination.

Recalls due to pathogens (disease-causing organisms) have recently increased on products that have been traditionally thought to be shelf stable or non-microbiologically sensitive, such as trail mixes, nuts, and frozen waffles. This has heightened the awareness of the critical role that environmental monitoring plays for the entire food industry.

Environmental testing is a complex, multi-faceted program that encompasses pathogens (such as Salmonella, Listeria monocytogenes, and E. coli 0157:H7), air (both passive and compressed), and other features in the facility. An environmental monitoring program that includes all the necessary steps to be successful will help validate the effectiveness of the sanitation procedures for non-pathogenic organisms. Expansion of the program will be discussed in depth in future articles, specifically after the modernized GMPs and potential requirements for environmental testing in the ready-to-eat industry are issued.

Please note that different parts of the food industry, such as meat and poultry, have regulatory requirements for the actual tests to be conducted and the frequencies that must be met. This article focuses on parts of the industry where these regulatory requirements have not been provided.

Microorganisms of Concern

The first step is to identify what you will test for. To do this, you need to determine the micoorganisms of concern to your product and process. A typical environmental swabbing program encompasses testing for Total Plate Count (TPC), yeast, and mold. Determine if additional spoilage organisms, such as Pseudomonas, Lactobacillus, or Bacillus subtilis are a concern with your product. If so, include those organisms in the swabbing program.

Raw Material Hazard Analysis

As outlined in the principles of Hazard Analysis Critical Control Point (HACCP), the first step is to assess your raw materials to determine what they may introduce into your processing environment. This requires close communication with your suppliers; Internet searches, including searches for recalls on products that are similar to what you make; specific requirements for the incoming materials; and your own experience and knowledge.

Processing Hazard Analysis –

Environment Temperature

What are the temperatures throughout the facility that are conducive to growth? Warm temperatures such as retort rooms, oven areas, and summer-time ambient areas would enhance Salmonella and other heat-loving organisms.

Finished Product Hazard Analysis

What are the historic and emerging potential issues affiliated with the finished product? Again, literature and Internet searches for recalls and other historic information is invaluable, as well as information already available to you, such as customer complaints.

Developing the Testing Plan

Swab Zones

Since very few locations have an unlimited budget for an environmental monitoring program, dividing swab sites by "zones" is one method of assuring key areas are consistently swabbed.

• Zone 1. Direct and indirect product contact surfaces including the interior of delivery systems (pipes, chutes, hoppers), mixers, recirculation brine tanks, food contact utensils, worktables, etc. Approximately 50 percent of the swabs should be done in Zone 1 areas.
• Zone 2 Non-product contact areas that are directly adjacent to product contact surfaces, such as the equipment framework and equipment housing. Approximately 25 percent of the swabs should be done in these areas.
• Zone 3 Non-product contact areas within the processing room that are more remote from product contact surfaces such as walls and drains. Approximately 25 percent of the swabs are from Zone 3 surfaces.

Action Levels

Total Plate Count – less than 1,000

Yeast/mold – less than 100

Coliform – less than 10

Additional spoilage organisms – Conduct a literature search for action levels based on the organism you are testing for. Typically, any presence is a cause for concern and further investigation.

Many locations test for pathogens in Zone 3 areas, which will be discussed in a future article. For parts of the industry that do NOT have regulations regarding a pathogen monitoring program, Zone 3 is the only area where pathogen testing is typically conducted. Again, these facilities do NOT do pathogen analysis in Zones 1 or 2.

Sample Sites

The sanitation crew will quickly figure out which locations are being tested if the same sites are tested week after week. It is recommended that several spots be selected, then testing conducted randomly through them. For example, if 10 swabs are done weekly in Zone 1, rotate the locations among a list of 40 or more different identified locations. Be very specific about the spot to be tested. For example, instead of "Mixer A," clearly identify the hopper discharge, behind a blade, or other spot that is difficult to reach or see.

Laboratory Selection

There are a number of factors to consider when chosing in-house or a contractual laboratory, but they are too numerous for this article. Regardless, if you decide to do pathogen testing in Zone 3, ensure that the tests are conducted at a laboratory that is designed and approved for this, since potential growth could contaminate the environment both inside and outside the laboratory.

Reaction to Adverse Findings

A high count can have one or more reasons for occurence, including testing errors, equipment issues, incorrect procedures or chemicals, or lack of understanding/adherence to the cleaning procedures.

Re-Swab

Clean and re-swab the area that had the high count as soon as possible. If the second swab is satisfactory, re-test the site during the next swabbing cycle (total of three sequential swabs at the same site). This will help determine if the abnormal results were a fluke or if additional investigation as to the source or cause is needed. However, if the second swab is also high, immediately investigate the equipment, cleaning procedures, and adherence to procedures by the sanitation crew.

Sample Errors

Ensure that the individuals collecting the samples are trained on handling of the swabs/sponges and size of area to be sampled. Most laboratories that test swabs have clear directions and other assistance on how sampling is to be conducted.

A common error is for the tester to swab areas they identify as "dirty." Educate the tester that the purpose of the program is to validate that the cleaning procedures are effective. Therefore, if there is visible residue, they already have proof that errors occurred. They should then report the problem for re-cleaning and an alternative site should be swabbed.

Equipment Design

Review the design, maintenance, and condition of the food contact equipment and tools. These need to be smooth, easily cleanable and non-absorbent. If issues are identified, the plant team (maintenance, engineering, sanitation, etc.) needs to develop and implement an action plan to rapidly eliminate pitholes, cracks, cavities, hollow rollers, and other features that can harbor micro-organisms. Until these microbe harborage points are eliminated, you cannot assure that your sanitation practices are fully effective.

Sanitation

Your sanitation chemical supplier is an invaluble resource. They should team with you to ensure that the chemicals being used are effective for the organisms of concern to your product and process, to ensure they are being used appropriately (temperature, concentration, application method), and to help develop written procedures.

Ensure that cleaning tools do not contaminate what is being cleaned or the environment. Things to look for include:

• Review the design, condition, and cleaning methods for the sanitation tools themselves, including wet vacs, buckets, brush.
• Are the tools color-coded for their use to ensure that the brush used to clean the floor drains is not then used to clean the mixers?
• Are the tools stored in a manner where they will not allow micro-organism growth or cross contaminate the area?

Conclusion

All locations that handle exposed ingredients, in-process foods, and finished foods need to develop and implement an environmental monitoring program to ensure the sanitation practices are effective in preventing potential product contamination. AIB

The author is HACCP Coordinator, AIB International.