Consider these nifty food safety practices before cleaning a production line while one nearby remains in operation.

BakingandSnack.com | August, 2015 | by Joe Stout.


In the food industry, many manufacturers make products with different formulations on several lines in the same production room. This presents a challenge since most of these lines are in close proximity or even adjacent to one another.


We are often asked about the potential risk of cross-contamination during the cleaning process or spreading allergens when cleaning one line while an adjacent one is operating. Bakers and snack manufacturers need to understand the challenges when cleaning an adjacent line and how to minimize the risks of cross-­contamination during this common practice at many food processing facilities.


First and foremost, protecting the products being made is the key to successfully cleaning a nearby operation. This process must also involve protecting ingredients and packaging supplies. Prior to starting the cleaning, bakers and snack manufacturers should complete a risk assessment that identifies the risks involved before developing controls to protect the food in production. Securing the operating line requires very controlled sanitation methods — each with unique challenges to both dry and wet processes.


While adjacent-line cleaning supports the business, food safety and sanitation programs support the production of safe food. Verifying the effectiveness of the controls identified in the adjacent-line cleaning risk assessment supports food safety.


Depending upon the process and product type, verification may come in different forms. Examples may include environmental monitoring, air exposure testing, clean equipment swabs, allergen swabs and random GMP audits. Any or all of these can aid in the verification of adjacent-line cleaning program effectiveness or provide learnings about areas requiring improvement.


For example, environmental monitoring of pathogens and non-pathogens collected during adjacent-line cleaning can supply crucial data about the presence of a number of issues. Such monitoring provides key statistics on whether adjacent-line cleaning practices are increasing risks with environmental air and what needs to be managed.


In a typical bakery, snack facility or food plant, products often have a variety of allergen profiles, environmental room requirements, varied production run lengths and microbiological risks. In some cases, customers may have different expectations for finished product testing. These demands result in the need for flexibility in the manufacturing environment, and many plants need robust, scientifically validated programs to enable cleaning when an adjacent line is in operation.


Understanding the underlying complexity of this common sanitation process will lay the foundation for ensuring food safety. Adjacent lines have exposed product contact zones or surfaces such as open belts, hoppers and lines and are scheduled for operation at the same time that cleaning of another line occurs. Lines separated by physical walls, closed design or by temporary walls are not considered adjacent lines.


If proper procedures are not followed, the full or partial cleaning of nearby lines could contaminate products, food contact surfaces, ingredients, packaging materials or any open product zone areas. This includes any situation with the potential to transfer pathogens, spoilage organisms, allergens, foreign material or other adulterants, even changes in relative humidity. All must be controlled during adjacent-line cleaning.


Often, food plants may need a clean break, which is a defined sanitation event that enables clear separation or disassociation of products both before and after the sanitation event. A clean break normally follows production lots that have been tested for pathogens or pathogen indicators. Some customers request finished product testing. In these cases shorter runs that minimize product on hold waiting for results cause operators to do adjacent-line cleaning today than in the past.


Conducting a risk assessment involves evaluating several factors, including transfer of spoilage organisms such as yeast and mold from one line to nearby one line. In a wet cleaning environment, the use of water could elevate the relative humidity that could foster the development of microbial growth in the environment.


During cleaning activities in a dry environment, allergens could be disturbed on the line and carried to an adjacent line via typical plant air currents. Although it’s not recommended, many facilities still use compressed air as a cleaning tool. In these cases, foreign material such as allergens can be easily spread throughout the production area. The preferred method for dry cleaning includes brush and vacuum cleaning with dedicated tools.



Here are a few key questions that should be asked during a risk assessment.

  1. Is there a safe distance between the line being cleaned and the operating line? The more distance the better. A good rule of thumb is a minimum of 20 ft.
  2. If water is used for cleaning, is low-pressure water of less than 50 psi used to minimize generation of aerosols, which could migrate to the operating line?
  3. Are there employee or equipment traffic patterns between cleaning and production areas? If so, could these lanes cause cross contamination?
  4. Do you see visible dust particles generated during the cleaning process that could reach the operating line?
  5. Could moisture from the cleaning process condense above open product zones or be a source for microbial growth?
  6. Drainage is also a troublesome issue. Will cleaning activities potentially cause a drain backup?
  7. If curtains are needed to prevent water overspray or dust penetration from one area to another, have they been cleaned before they are used?
  8. Do employees who clean the line follow proper GMP practices before returning to operate in the production area?



Here are a few tools to determine the risk of cross contamination.

  1. Use swabs to measure non-pathogen microbial activity on adjacent lines during the cleaning process and compare them against normal activity during normal operation.
  2. Employ a hydrometer to measure relative humidity during wet cleaning.
  3. Collect air samples for microorganisms such as yeast and mold.
  4. To measure potential allergen dust migration while in the sanitation mode, follow the “Stout Environmental Allergen Dust Test Method” on www.commercialfoodsanitation.com.
  5. Use a GMP check list and a well-­defined SSOP that includes procedures developed which address concerns elevated in the risk assessment.


In summary, take time and ensure you consider all of these items before scheduling an adjacent-line cleaning event. In today’s industry, bakeries and snack producers are searching for any way to increase production and reduce downtime in their operations. To ensure that food safety isn’t compromised, a full understanding of the risks and plans to mitigate such risks must be in place prior to the initiation of adjacent-line cleaning.