ATP Best Practices

A robust environmental monitoring program typically features three primary components: an ATP sanitation monitoring system for general cleaning efficacy, an allergen monitoring program when allergens are present in the facility, and a pathogen monitoring program to guard against microbial contamination. Below is the initial installment of a two-part series addressing the first two of these components.

The establishment of a robust hygiene monitoring program is at the core of any food safety initiative. Adenosine triphosphate (ATP) hygiene monitoring systems have become the de facto standard used for measuring the effectiveness of cleaning efforts in the food production industry

These systems measure ATP, a molecule produced in every living cell, to indicate the amount of cellular-based (aka, “organic”) residue left on a surface after cleaning. While not necessarily a direct indicator of microbial presence, organic residues can contain allergenic proteins and or product fragments that can contribute to off-taste in subsequent production runs. These organic deposits can serve as a reservoir for pathogenic microorganisms.

While ATP hygiene monitoring systems have been used in food production facilities for over 20 years, there has been little standardization on their applications. Many users have adopted simplistic practices in an attempt to simply “have something” and have missed out on the full value that can be derived from a strong monitoring program. There has also been a great deal of misinformation concerning the appropriate implementation and interpretation of results.

Neogen Corporation, in association with NSF International, has recently published a handbook titled, “Best Practices for Effectively Implementing an ATP Sanitation Monitoring Program” to help facilities wade through the misinformation and go about the process in a more structured and scientific process. This blog features excerpts from the handbook which can be downloaded. We’ll begin by exploring the concepts of validation and verification and some guidance on cleaning to a validated standard.

Validation vs. verification

Validation is the process a facility undertakes to ensure the effectiveness of a particular operation. In this case, the process refers to a facility’s materials and procedures used for cleaning after a production run.

The goal of the cleaning process in a food production environment is to effectively remove all particulates, residues and microbial organisms to a safe and/or satisfactory level. Validation is proof that the goal can be achieved. It must be based on logical in­ferences and measurable results, and those results must be translatable to standards that can be used for routine monitoring during a normal production cycle.

Validation is typically performed until the expected outcomes are achieved and then repeated on a scheduled basis — or when the underlying assumptions used for vali­dation have changed.

Verification is the routine monitoring of the process to determine adherence to the validated standard. This is typically done after each cleaning, and results are compared against the performance levels obtained during the validation process. Results that fall outside the validated standard indicate that one or more components of the cleaning process failed. A facility’s verification process is typically incorporated into its Sanita­tion Standard Operating Procedure (SSOP).

Cleaning to a validated standard

Cleaning in a food production environment is a critical base to any facility’s food safety program. Cleaning failures can result in microbial, chemical (including allergens) or physical material contamination of future production.

The challenge for most food production facilities is in establishing objectives and stan­dards that can be measured in a meaningful way. Since most food contaminants that can represent a safety issue for consumers are either microbial, chemical or allergenic proteins, the optimal cleaning process will result when these entities are either re­moved and/or rendered inert. For that reason, most facilities use a cleaning process that focuses on the removal of the soil that can house these contaminants, followed by a sanitation step designed for microbial kill.

Step one in the validation process is determining the efficacy of the current cleaning program. In a wet-cleaned or clean-in-place (CIP) environment, this can be accomplished through adenosine triphosphate (ATP) measurements directly following cleaning. If the facility utilizes a two-step clean and then sanitize process, measurements would typically occur following the cleaning but before the sanitation step to minimize the cost of sanitizing twice. The exception to this rule would be a sanitation step that enhances the removal of the soil.

The validation process requires the identification of test sites that reflect a representative sampling of the individual items being tested. As an example, product may flow along a production line through chutes and conveyors before arriving at a slicer and finally into a box or bag. Each unique surface that comes into contact with the product should be considered a unique test site. Harborage and difficult-to-clean areas should be a particular focus. It is also important to take into account non-food contact surfaces that could contribute to environmental contamination during production cycles.

Identifying a representative sampling site also implies the area that will need to be re-cleaned if it receives a failed ATP result. If, as an example, conveyor #1 is identified as a test site, any sample taken on any surface of the conveyor would be considered representative of the cleaning done for that entire piece of equipment. If a separate cleaning process is performed for any item of conveyor #1, it would imply a unique test site in the sample set. Once all test sites have been identified they should be recorded in a facility’s SSOP and are typically referred to as the facility’s Test Plan sites.

A SSOP must be adjusted to address sample sites that routinely fail to be cleaned effectively. Using the established RLU thresholds as a standard, a best practice approach to validating the SSOP would occur when the process achieves a passing result on three consecutive events.

Neogen offers the industry leading AccuPoint Advanced ATP Sanitation Monitoring System which provides the most accurate and consistent results as proven by an industry-leading source. Find out more about AccuPoint Advanced ATP Monitoring System.