Cleaning equipment, preparation areas and the production lines of a food manufacturing site is necessary to eliminate allergen residue and the potential for cross contact. As facilities can vary in complexity, food materials, the allergen type, number, and nature, equipment type, and food contact surfaces, cleaning parameters may be unique to each process or site.

Hang Up is any residue or material that has accumulated at a specific area (point) within processing equipment on a manufacturing line and can become distributed into a subsequent product is Hang Up. It represents all forms of environmental cross contact.

Examples include residue from –

  • pipework
  • equipment such as pumps, mixers, homogenizers
  • conveyors
  • airborne dust
  • utensils

A Hang Up point is a specific area (point) within processing equipment on a manufacturing line where material may accumulate instead of flowing through freely. It is important to correctly identify hang up points in your manufacturing facility.

Some manufacturing facilities may be able to eliminate cross contact due to processing by having cleaning programs which have been validated to eliminate any product on the lines. Some plants, such as chocolate or dry-blend plants, face more significant challenges when eliminating cross contact allergens.

A cleaning program includes documented and validated cleaning procedures that are designed to remove food allergens and minimise cross contact. It should be continually reviewed to ensure it is up to date, suitable and effective.

Equipment or a line that is sanitized microbiologically is not necessarily clean from allergenic protein. It shouldn’t be assumed that cleaning practices that control microbiological contamination effectively control allergen cross contact.

A cleaning schedule outlines the methodology and frequency of the cleaning program. Consider using expert knowledge from a cleaning specialist when designing the schedule, particularly when foods are complex. The cleaning schedule should set out the areas, equipment and utensils that are to be cleaned, the cleaning processes and occurrences. It should include how the cleaning will be monitored and who is responsible.

A cleaning matrix sets out the order of the cleaning program and can be used to instruct cleaning regimes for foods that contain allergens. A cleaning matrix may already exist for other purposes such as managing flavour transfer, vegetarian or organic foods, and may be modified to include allergen considerations.

Occurrences that fall outside of the regular cleaning matrix, such as running a new product development trial that introduces a new allergen, should be accounted for. If a new allergen is introduced, changes to the cleaning program may be required with validation and verification steps in place to ensure that the cleaning is effective.

Click here to see some examples of a cleaning matrix. Cleaning Matrix

Wet and Dry cleaning

Removal of allergenic protein from equipment should begin with a physical clean that may include the disassembling of equipment, and for wet environments a chemical clean (such as a caustic wash) and for a dry environment dry flushing or vacuuming. Visual inspection after cleaning is required, however visually clean equipment may still harbor allergenic proteins. Validation to determine that the cleaning processes are sufficient is required.

Wet cleaning – Using high pressure hoses should be discouraged as they can contaminate other lines whilst allergen cleaning, use low pressure hoses wherever possible.

Allergens may not be removed or destroyed when exposed to heat, therefore some cleaning processes such as a hot water flush may not be enough to remove allergens.

Dry cleaning – Using compressed air for cleaning can contaminate other lines whilst allergen cleaning so should be discouraged. Vacuum cleaners can be an effective way to remove the allergens.

Cleaning validation is confirming, by use of evidence, that the cleaning processes that are in place are effective in removing the allergenic protein from the equipment or line etc. All parameters should be assessed in the process (such as chemical concentration, time, temperature, residual contact times or flow rate for a CIP (clean in place) clean).

  • Perform visual inspection of the equipment to check that it is clean
  • Inspect / break down the equipment and inspect areas where product can accumulate and or not be cleaned readily
  • Use robust analysis to provide data and evidence that the processed remove the allergen
  • Repeat validation exercises several times (with a minimum of three times) to ensure that the results are repeatable and account for variations between shifts and products produced

Cleaning verification are activities to check that the cleaning steps are taking place and are meeting the standard. For example, are all cleaning procedures documented, is the cleaning matrix clear, is the cleaning schedule correct and up to date, are the operators following it? Routine cleaning verification should be in place to ensure that cleaning is effective. If the verification shows that cleaning is not adequate, equipment may need to be cleaned again. Verification activities may include rapid allergen test strips or swabs, ATP, and visual standards.

Sample types for cleaning validation include but are not limited to swabs, rinse waters, product flushes, finished product (post clean)

  • Where possible collect rinse waters as they are more representative of the process
  • When swabbing, test product contact surfaces
  • Need to test more than 1 sample, especially when multiple vats may be used to produce a product

When conducting an allergen risk review of the effectiveness of cleaning, additional considerations include:

Cross contact can occur when spills of allergenic material are not cleaned up promptly.

  • Does the facility have spill kits for allergenic products / raw materials?
  • Is there a controlled way of disposing of the spill material?
  • Are there clearly defined procedures in place?

Cleaning Standard Operating Procedures (SOPs)

  • SOPs should be adaptable when new allergens are introduced, and cleaning may be different for each allergen
  • Do the cleaning processes allow enough time to clean?
  • Is there sufficient cleaning at product changeovers?
  • Collaborate with your chemical supplier and qualified consultants to ensure the system is set up effectively

Cleaning validation and verification

  • Does site have a routine cleaning verification process in place to ensure that cleaning is effective?
  • What do the results of the verification testing mean?
  • Are the methods implemented able to also be used for allergen cleaning efficacy?
  • Is the allergen detectable by analysis?
  • The type of testing in place may be based on risk and may be scaled depending on if the facility makes claims.
  • Current micro testing results may provide an indication of how effective the cleaning is. Note however that micro results are not appropriate for allergen identification.
  • Is the sampling method and are the same sample points suitable for allergen testing?

Cleaning personnel

  • Are the cleaning personnel trained, experienced and consistent?

Tools and reusing equipment

  • Dedicated colour coded cleaning tools for allergen cleaning are recommended to ensure that cross contact is minimised – this may be appropriate where only a few allergens are in the facility. Otherwise coding may be by surface type.
  • Cleaning tools should be checked to ensure that allergenic materials are not lodged in the tools. It is important that the cleaning tools and equipment are also cleaned to prevent allergen cross contact.

Cleaning foams and hand-wash
Some cleaning chemicals and hand wash soaps/sanitisers can contain added allergenic ingredients – Refer to the technical specifications for an allergen statement.

An effective AMP will include procedures in place for:-
Cleaning – Procedures to manage raw material spills, and for cleaning the facility, equipment, and tools to prevent allergen cross contact are in place. Cleaning validation and verification is monitored and reviewed.
Waste – Procedures in place to control waste product and packaging that contain allergens. For example, a package that stored a milk based ingredient, should not be reused for a different ingredient that does not contain milk.