Surface sanitation plays a critical role in preventing cross-contamination, which is a key contributing factor to foodborne disease. Its goal is to reduce microbial levels on surfaces to safe levels. The process typically involves three sequential steps: wash, rinse, and (when necessary) use an antimicrobial treatment. Washing removes visible dirt and organic matter using soap or detergent and water. Rinsing follows, using clean water to remove any remaining soap and debris. Finally, when warranted by the type of surface and contamination event, an antimicrobial treatment—such as a sanitizer or disinfectant—is used. Each step is essential; together, forming an effective strategy to reduce or eliminate foodborne pathogens.

However, success depends not only on using the correct methods but also on consistent and proper execution. Research suggests that establishments with structured food safety systems—including clear policies, staff training, and monitoring protocols—are more successful in their implementation of risk management practices, such as surface sanitation. Although the procedures and rationale behind surface sanitation are well understood and well documented, improper or incomplete practices continue to be reported.

Ramifications of Improper Sanitation Practices

At the core of improper or incomplete practices within retail foodservice settings is a lack of clarity in sanitation terminology and the standards outlined in the U.S. Food and Drug Administration's (FDA's) Model Food Code. The Food Code provides detailed procedures for cleaning and sanitizing food contact surfaces but offers limited guidance for the treatment of non-food contact surfaces. Additionally, while terms like sanitize, disinfect, and antimicrobial are well-defined, foundational terms such as clean, wash, and rinse remain undefined, leaving them open to subjective interpretation by both end users (i.e., cleaners) and regulators (i.e., environmental health specialists).

Moreover, while the Food Code emphasizes sanitizing, it gives far less attention to the prerequisite steps of washing and rinsing—both critical prerequisite steps for effective sanitization. Compounding the problem is the absence of a technical or quantitative definition for what constitutes a "clean" surface, leaving operators to rely on visual inspection, which is an inherently unreliable and inconsistent monitoring method. The lack of detailed standards and clear definitions for all three steps of the surface sanitation process can result in inadequate cleaning practices and persistent contamination risks. This is especially concerning in retail foodservice environments where hard, non-porous surfaces are common and recognized as key vectors for the transmission of foodborne pathogens.

One reason for these inconsistencies is that regulatory oversight of sanitation practices in retail foodservice operations is somewhat fragmented, with three federal agencies providing different types of guidance. FDA sets sanitation standards for retail foodservice establishments through the Food Code, which represents FDA's best advice for a uniform system of provisions addressing the safety and protection of food offered at food establishments. The U.S. Environmental Protection Agency (EPA) defines and regulates antimicrobial products under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), requiring all products that claim to kill pathogens on surfaces—such as sanitizers and disinfectants—to be registered with EPA before sale or distribution in the U.S. Lastly, the U.S. Centers for Disease Control and Prevention (CDC) works to prevent and control diseases. CDC provides evidence-based infection control strategies, including surface sanitation guidelines for various settings and situations. When federal agencies provide information that is not consistent, it can reduce the willingness to accept and act upon official guidance, especially during crisis situations, which notably occurred during the COVID-19 pandemic.

“Surface sanitation provisions presented in the Food Code differ for food contact and non-food contact surfaces due to the different risk profiles of these two types of surfaces.”

In the U.S., the FDA Food Code sets standards for cleaning and sanitization in Chapter 4. In food establishments covered by the Food Code, surfaces are classified as either food contact (i.e., surfaces used to prepare, serve, transport, and/or store food) or non-food contact (i.e., surfaces that typically have no direct contact with food). Surface sanitation provisions presented in the Food Code differ for food contact and non-food contact surfaces due to the different risk profiles of these two types of surfaces.

According to the Food Code, all surfaces, regardless of type, must be washed and rinsed, while only food contact surfaces must be sanitized after washing and rinsing. The notable exception is after a bodily fluid event, which is discussed later. Sanitizing surfaces can be difficult for items constructed of both food contact and non-food contact surfaces, such as refrigerators and preparation tables, as it might be unclear to the end user which parts of the surfaces fall into each category. Another issue is high-touch surfaces—objects people frequently touch with their bare hands. High-touch surfaces are typically classified as non-food contact surfaces and, per the Food Code, are only required to be kept clean and not treated with an antimicrobial. Other guidance documents state they should be cleaned and disinfected.

The above-mentioned issues are further compounded in the case of bodily fluid cleanup. Proper cleanup of bodily fluids is crucial for preventing the spread of infectious diseases, maintaining a safe environment, and complying with health regulations. Bodily fluids like vomit and fecal matter can contain harmful pathogens, such as human norovirus, which can easily spread and cause illness among staff and customers. After a bodily fluid event, all surfaces must be cleaned (i.e., washed and rinsed) and then disinfected. Of note, disinfection was first defined in the Supplement to the 2022 FDA Food Code. Importantly, disinfection is not sanitizing. Disinfection is the elimination or inactivation of targeted pathogenic microorganisms (i.e., bacteria, viruses, fungi, and other microorganisms that cause infections), whereas sanitization is the reduction of the level of pathogenic bacteria to safe levels. A single vomiting or diarrhea event can trigger an outbreak, if not handled correctly. 

Compounding the issue is that end users—such as cleaners and regulators (e.g., environmental health specialists)—often rely on visual inspection or tactile feedback to assess surface cleanliness following washing and rinsing. This approach is subjective and unreliable. Although objective tools for monitoring surface sanitation are available, each comes with its own limitations and may not always be practical in routine settings.

Tools for Monitoring Surface Sanitation

Adenosine triphosphate (ATP) bioluminescence testing is one commonly used monitoring tool. It involves swabbing a surface and analyzing the sample for ATP—a molecule found in all living cells and food residues. A low or undetectable ATP reading generally indicates a "clean" surface. Results are rapid, typically available within minutes using a handheld luminometer. However, the equipment is expensive, often exceeding $2,000, and requires the use of disposable test strips. Furthermore, ATP is also found in food residues, meaning a positive reading does not necessarily indicate that harmful pathogens are present. Viruses such as norovirus, which do not produce ATP, cannot be detected by this tool. Furthermore, certain cleaning agents, including chlorine and citric acid, can interfere with ATP readings. As such, while ATP testing is useful, it must be applied with an understanding of these limitations.

Fluorescent marking is another tool that can be used. These markers are applied to surfaces prior to cleaning, and an ultraviolet black light is used afterward to check whether the marker has been removed—signaling the surface was physically wiped. This method is easy to use but does not verify whether an effective cleaning agent was applied or if microbial contamination has been reduced or eliminated. Importantly, only food-safe markers should be used on food-contact surfaces.

Dyne pens, which measure a surface's hydrophobicity (i.e., ability to repel water), are yet another option. These pens assess how water interacts with a surface—greasy or oily residues tend to repel water. While helpful in detecting certain types of contamination, this method is limited in practicality. Different materials exhibit varying baseline readings, and the pens degrade over time, making them costly to maintain.

“While the evidence is clear—surfaces must be thoroughly washed and rinsed before applying antimicrobial treatments—practice remains inconsistent.”

Finally, microbial testing is considered the gold standard. It involves collecting surface swabs and sending them to a laboratory to detect microbial presence, including specific pathogens. Although highly accurate and detailed, these tests are costly ($25 to <$100 per individual test) and slow, often taking up to a week to deliver results. This delay renders them impractical for routine or immediate feedback. Consequently, many establishments default to the least reliable method: human sight, which we know is highly unreliable.

Wash and Rinse Steps

Another concern is the impact the wash and rinse steps have on the effectiveness of sanitizers. Sanitizers must come into direct contact with microorganisms to be effective. Any remaining debris or organic material on a surface can block contact or even degrade the sanitizer, reducing its efficacy. This illustrates the equal importance of the wash and rinse steps.

While the evidence is clear—surfaces must be thoroughly washed and rinsed before applying antimicrobial treatments—practice remains inconsistent. Cleaning prior to using an antimicrobial is not just procedural; it is scientifically necessary. Organic matter such as food particles or bodily fluids can interfere with antimicrobial effectiveness. These residues can physically block pathogens from contacting chemical agents or thermally inactivate certain components, such as chlorine or quaternary ammonium compounds, by binding to or degrading the active ingredients. The actual performance of both chemical and thermal antimicrobials depends on direct exposure to the pathogens. Chemical agents like chlorine and hydrogen peroxide require sufficient contact time and concentration to be effective. If soil is left on a surface, it can form a barrier that impedes this contact, rendering the treatment less effective or even entirely ineffective.

Thermal sanitization, such as hot water rinses reaching at least 160 °F (71.1 °C), face similar challenges. Soil can act as an insulator, preventing the surface from reaching the necessary temperature or reducing the time it stays at that temperature, thereby reducing the microbial kill rate. Without clear terminology, measurable standards, and affordable monitoring tools, ensuring compliance with the wash and rinse steps will continue to be a challenge.

Surface Sanitation: The First Line of Defense

In conclusion, surface sanitation is a critical first line of defense against foodborne illness, but its effectiveness hinges on a clearly defined and consistently executed process of wash, rinse, and use of appropriate antimicrobials. Unfortunately, insufficiently detailed regulations, inconsistent terminology, and operational challenges often undermine its success in real-world settings.

To address these issues, regulatory agencies must standardize definitions and provide sufficient details to properly execute all three steps. Surface sanitation cannot be left to guesswork—it requires diligence, proper tools, and above all, a shared, clear understanding of the process. Without this clarity, even well-intentioned efforts may leave the public at risk.

References

1. Thomson, A. and M. Wilson, "Building a Skilled and Capable Workforce for the Food Industry: Simplifying Food Safety Language." Food Safety Magazine. December 31, 2023. https://www.food-safety.com/articles/10001-building-a-skilled-and-capable-workforce-for-the-food-industry-simplifying-food-safety-language.
2. New South Wales Food Authority. "Biosecurity and Food Safety: Listeria Outbreak Investigation Summary Report for the Melon Industry." October 2018. https://www.foodauthority.nsw.gov.au/sites/default/files/_Documents/foodsafetyandyou/listeria_outbreak_investigation.pdf.