Requirements for Validation of Cleaning Procedures:
Where cleaning procedures are part of a defined prerequisite plan to control the risk of a specific hazard, the cleaning and disinfection procedures and their frequency shall be validated and records maintained.
What is Cleaning?
Cleaning is a physio-chemical process involving a number of factors
Objective – prevent contamination and cross[1]contamination
Elimination or reduction – hazards
Variety of hazards to be considered
Biological, Physical, Chemical and Allergens
Residuals remaining from detergents
Hazards
Biological
Bacteria, yeasts, moulds, viruses, etc
Physical
Wood, metal, plastic, etc
Chemical
Environmental, process, ingredients, etc
Allergens
What is Cleaning Validation?
Validation means Proof that the approved cleaning procedure is capable of producing safe food
Food businesses by law need to clean and sanitize their facilities. This is required to produce safe and legal food products and remove hazards such as pathogens, allergens and chemicals.
Food businesses employ Standard Sanitizing Operation Procedures (SSOP) to achieve this.
In order to ensure that these methods are in fact capable of removing the hazards and reducing the risk to an acceptable level – validation of the cleaning procedure is often required. Particularly for High-Risk unit operations.
Simply setting up a procedure and checking it a few times (e.g., ATP, swabbing and culturing, residual testing etc.) is not enough to validate a cleaning method as it will not account for the possible variation from employees, chemicals and other parameters. Validation of cleaning methods can be conducted statistically using a capability study.
When is Cleaning Validation Required?
When risk assessment or legislation requires it
Critical cleaning, e.g., between manufacturing of one product and another or specific contact surfaces
Not necessarily for non-critical cleaning, e.g., between batches of the same product or of floors, walls, the outside of vessels
Cleaning Validation Pre-requisites:
Before any validation can be conducted, you must first put in place certain requirements
Validation is basically setting up an experiment to prove an hypothesis
In this example we are looking to prove that a cleaning procedure is in fact capable of achieving the objective of producing safe and legal food
All this should be documented in a procedure for conducting the validation
Cleaning Validation Procedure:
Cleaning SOPs for cleaning processes in place
Cleaning schedules should also be in place
Cleaning Validation Procedure required:
contact surfaces
cleaning after product changeover
between batches in campaigns
categorizing products for cleaning validation and
periodic evaluation and revalidation of the number of batches manufactured between cleaning validations.
Objectives & responsible people
Cleaning SOP’s
Cleaning chemicals, concentration, solution volume, water quality
Time and temperature
Flow rate, pressure and rinsing
Number of cleaning cycles
Description of the equipment – make, model, complexity of design
Training of operators
Equipment used for monitoring (e.g., conductivity meters, pH meters)
Sampling procedures (e.g., direct sampling, rinse sampling, in process monitoring and sampling locations) and the rationale for their use
Analytical methods
Acceptance criteria (with rationale for setting the specific limits)
Revalidation requirements
Cleaning Chemicals
Solubility of the materials to be removed
Design and construction of the equipment and surface materials to be cleaned
Minimum temperature and volume of cleaning agent and rinse solution
Manufacturer’s recommendations
Released by quality control and meet food standards or regulations
Composition known
Easily removed with rinsing – demonstrated – with acceptable limits defined
If persistent residues – avoided
Consider also detergent breakdown
Categorising
Very similar cleaning procedures for products and processes – no need for individual validation
“Worst case” may be acceptable and should be justified
Representative product – most difficult to clean
Equipment – only when it is similar or the same equipment in different sizes (e.g., 300 l, 500 l and 1000 l tanks).
Cleaning Validation Reports
The relevant cleaning records – (signed by the operator, checked by production and reviewed by quality assurance) – and source data (original results) should be kept
The results of the cleaning validation should be presented in cleaning validation reports stating the outcome and conclusion
Equipment
Cleaning of contact surfaces to be validated. Critical areas should be identified
Dedicated equipment for:
products which are difficult to clean,
equipment which is difficult to clean,
products with a high safety risk
The design of equipment may influence the effectiveness of the cleaning process
Which are the critical areas for sampling?
What would be considered an appropriate approach for cleaning validation for this piece of equipment?
What is important about cleaning validation for components / parts of equipment?
Consider also the different materials, e.g., stainless steel contact surfaces, silicon seals and others
Sampling
Two methods of sampling:
direct surface sampling and
rinse samples
Combination of the two – most desirable
Resampling
May indicate residue presence and poor cleaning procedure
Direct Surface Sampling (direct method)
Most commonly used method
Use “swabs” – type of sampling material should not interfere with the test
Factors to be considered include:
supplier of the swab,
area swabbed, number of swabs used, whether they are wet or dry swabs,
swab handling and swabbing technique
Other factors include:
location from which the sample is taken (including worst case locations)
composition of the equipment (e.g., glass or steel)
Critical areas (hardest to clean)
g., in semi-automatic/fully automatic clean-in-place systems
Use appropriate sampling medium and solvent
Rinse Samples (indirect method)
Allows sampling of:
a large surface
areas that are inaccessible or that cannot be routinely disassembled
Provides an “overall picture“
Useful for checking for residues of cleaning agents
In combination with other sampling methods such as surface sampling
Analytical Methods
Validated analytical methods – able to detect residuals or contaminants:
specific for the substance(s) being assayed
at an appropriate level of cleanliness (sensitivity)
Sensitive and specific – may include:
ELISA
Specific Allergen Testing
Non-Specific Testing
Validation of the analytical method should include:
limit of detection (LOD)
Reproducibility
Establishing Acceptable Limits
Limits: Practical, achievable and verifiable
Rationale: Logical, based on knowledge of materials
Each situation assessed individually
There should be no residue from:
Previous product
Reaction by-products and detergents
Cleaning process itself (e.g., detergents or solvents)
Remember: Uniform distribution of contaminants is not guaranteed
The limit-setting approach:
be product-specific
group products into families and choose a worst case product
group products into groups according to risk
Limits may be expressed as:
a concentration in a subsequent product (ppm),
limit per surface area (cfu/cm2), or
in rinse water as ppm.
Visual
Certain allergenic ingredients and highly potent material should be undetectable by the best available analytical methods
Cleaning Validation Sample Procedure
No absolute or correct way to do validation
The following is a good generic example of how a validation may be conducted
