How Clean is Clean?

The scope of hygiene and sanitation is more than the abstract state of being clean and free from dirt. Discover how manufacturing companies and food producers can achieve the industry standards through testing and monitoring.

By Robert Artuso and Elvie Ngayawon

No matter how any production facility may look apparently clean on the outside appearance, it could never be an assurance that it is safe from pathogens and chemical contaminants. In the manufacturing industry, it is a must that cleaning is done on a regular basis. Cleaning protocols implemented by the management of the facility depends on the equipment, nature of products, and materials used. But, regardless of the specifications and methods of cleaning employed, the primary objective of cleaning is to ensure that the quality and safety of products are being maintained even during the production process. If insufficient cleaning and sanitation are employed, pathogens and allergens lurking in the environment, especially on unclean food contact surfaces, may compromise food safety.

The overall thought leaves every food producer this question: how can a food manufacturer tell if the production facility is entirely clean? Over the years, experts have developed hygiene and sanitation protocols and technologies to quantify and verify the degree of cleanliness. These techniques and tools help the management of the food-producing facilities in ensuring proper processes that comply with food safety standards and regulations.

How Clean is Clean?


Almost everything involved in the production process could be a mode of introduction and transportation of pathogens in a food manufacturing facility—workers, raw materials, machinery, pests, and water. Pathogens could either be transient or resident. Those that pass through and do not stay in the facility are the transient pathogens. These are mostly introduced by raw materials, mobile equipment, personnel, dust, and aerosols. However, transient pathogens could easily be eliminated through effective cleaning processes. On the other hand, if contamination is high or cleaning is inadequate, pathogens could proliferate and establish themselves in hard-to-clean areas of the production facility, and eventually become resident. These pathogens require more rigorous cleaning measures, as these are more resistant to typical cleaning and sanitation procedures. Food pathogens, such as Salmonella spp., Campylobacter, and Listeria spp., are commonly found in food handling facilities.


As every company that handles production and operation of consumer products strives for high quality and customer satisfaction, hygiene and sanitation have become a priority. One way to check the effectiveness of all cleaning and sanitation activities is to implement an environmental monitoring program that includes a pre-operation program. Several types of monitoring tools can be used for this purpose. To check the level of cleanliness and quality of consumer products, adenosine triphosphate (ATP) sanitation monitoring system entered the scene. It is one of the most advanced technologies in environmental monitoring. Using an ATP system is an easy and quick gauge of a facility’s cleanliness. It is easily customized for the specific equipment, product, and processes used in any food production facility. ATP systems have become the de facto standard of food and beverage manufacturing facilities in monitoring hygiene and sanitation efforts. The systems set an objective, recordable, and traceable standard to help avoid the consequences of substandard sanitation efforts.


Adenosine triphosphate, commonly known as the “ATP”, is the energy source in all living cells. Basically, all food and beverages, as well as microrganisms, such as bacteria and Yeast and Mold, contain ATP. As these come into contact with pipes, tanks, or any other food contact surfaces during the production period, ATP contents are left in the surface that these materials went through.

Rob Soule from Neogen Corporation, who spent a great deal of time working with food safety professionals to share the benefits of ATP sanitation monitoring systems to operations and facility systems, shared: “Properly utilized sanitation monitoring systems allow instantaneous detection and measurement of ATP on food contact surfaces, which provide an objective and actionable tool for monitoring of a facility’s sanitation efforts. ATP systems provide immediate feedback if the facility’s sanitation efforts have been thorough enough to prevent contamination of its products with residues or microorganisms from previous production runs.”
The amount of ATP detected and the surfaces where ATP was found give quantitative signals to the company personnel on possible trouble spots, which need to undergo another sanitation process prior to the start of the production cycle. However, ATP sanitation monitoring systems are not designed to define various sources of ATP. Detection of excessive amounts of ATP does not definitely identify the source of ATP.


It is a common misconception that the results received from ATP testing systems in relative light units (RLUs) for surface samples (for example) should, in some way, correlate with the microbial total plate count results for the same samples. The RLU results returned through the use of an ATP system can be any combination of benign food residues and more potentially harmful bacteria.

“Some of those I work with would like these ATP systems to be more specific, but they are not. They are just strictly telling us how well we’ve cleaned,” Soule said. “You could have an extremely high RLU reading that, in fact, detected the ATP from very few microbes. We need an inherent cleaning process to minimize the risk of microbial growth and cross-contamination. The residual food or beverage itself can be a problem if there is an allergen cross-contamination concern in the facility,” he continued. “But, the bigger concern is usually what could possibly grow in the food or beverage residue during the production process, and could subsequently contaminate food products.”

Therefore, it is recommended that ATP testing should also be supplemented with monitoring the levels of appropriate indicator organisms. These indicator organisms provide insights on the overall level of contamination in the facility or on food contact surfaces.
Some of these indicators are the levels of total aerobic plate count and enterobacteriacea. In addition, facilities could also do pathogen-specific environmental testing to monitor the presence of specific pathogens like Salmonella spp. and Listeria spp., which may be present as transient or resident microorganisms.

Similar to the pathogens in the environment, indicators should be monitored in consideration of the facility environment and products. For example, Salmonella spp. is usually found in facilities producing dry products and using dry cleaning, while Listeria spp. is common in wet and cold facilities. The right testing and results will determine the right cleaning and sanitation procedures.

“We need an inherent cleaning process to minimize the risk of microbial growth and


In order to assess the effectiveness of the cleaning, it is important to know where to test. Most food handling facilities employ a strategic sampling method like the zoned approach. The zones are classified according to the cross-contamination risk that they may impose on the production process.

Zone 1

Food contact surfaces (e.g., conveyor­ belt, pipes)

Zone 2

Surfaces adjacent to food contact surfaces (e.g, leg of equipment, lids, and covers)

Zone 3

Other areas and surfaces in the vicinity where food is produced (e.g., floor, walls)

Zone 4

Areas where food is not produced (e.g., worker lounge)

It is recommended to test for ATP and total aerobic plate counts levels in zone 1, where food contact is high. Testing for pathogens in zone 1 is seldom, because testing for pathogens depends on the product and other factors. For facilities conducting pathogen tests in zone 1, it is recommended that they follow a test-and-hold process until results are obtained. This is to control the risk of cross-contaminating the other areas and products. On the other hand, zones 2, 3 and 4 are typically the subject of environmental pathogen testing, since these may impose risks of resident pathogens. In case positive results are obtained, facilities should be prepared in eradicating the pathogen before it could potentially contaminate other areas and products.


 Hygiene and sanitation will always be a key component of an effective food safety system. It requires involvement and interplay of the different factors and people involved. As years pass by and improved equipment continues to flourish, testing systems have become a vital part of the industry in ensuring hygiene and sanitation among every company’s facilities and operations. However, even though technology gives each producer several innovative ways to determine the level of cleanliness in all facilities, the success of the implementation of sanitation control procedures will still depend on the staff involved in conducting cleaning procedures, prerequisite HACCP-based programs, and planning for long term and effective sanitation goals.

How Clean is Clean?

“Hygiene and sanitation will always be a key component of an effective food safety system.”

Aside from implementing effective hygiene and sanitation procedures, it is important to include the employees as part of the hygiene and sanitation process. Educating employees on proper hygiene and food handling skills would contribute to the goal of reducing the risk of contamination within any facility. This also creates a culture of prioritizing cleanliness.

Food Safety Trends Philippines will leave you three actions to consider in using testing systems for food safety assurance: 1) get the staff involved in plan development, implementation, monitoring, and verification; 2) conduct trainings that are focused and practical; 3) and provide records of training and incentives. Thus, it is never too late to have a combination of effective testing systems and proactive staff members. Hygiene and sanitation are a major consideration for the success of any food business. Promoting this duo is a continuous effort that encourages every food producer to aim for a clean, safe, and consumer-friendly environment.

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