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Cleaning Validation in the Food Industry

EHEDG is about to publish a comprehensive hygienic design guideline dedicated exclusively to cleaning validation. Chair of the EHEDG Working Group Cleaning Validation Hui Zhang (Unilever): ‘Everyone involved in food processing who wants to strengthen the reliability of their cleaning validation processes can put this guideline to good use. It will help to tackle cleaning challenges and minimise contamination risks.’ After publishing this guideline, EHEDG will include the topic of Cleaning Validation in its training program in order to further support medium and small companies to optimise their cleaning validation processes. Please also read the article below.



The Working Group Chair:

Hui Zhang currently works as a Quality Expert for the Unilever Global Quality Group. Her focus area is hygienic design, cleaning and disinfection. Before she started her job at Unilever, she obtained her master’s degree in molecular plant science at Leiden University. As the chair of the working group Cleaning Validation, consisting of multidisciplinary experienced experts, her main responsibility is to provide leadership and facilitate the process of the guideline development, from drafting towards completion. She also serves as the first point of contact when people have feedback, technical questions or any comments about the contents of the guideline.


The Working Group Members 

The members of this working group work at diverse companies, from manufacturers of foods and food raw materials, via manufacturers of cleaning and disinfection chemicals to machinery manufacturers and consultancy companies that provide food hygiene services and hygiene solutions. 


What are the basic criteria which food processing companies should apply to determine the correct degree of cleaning validation, specifically enhanced cleaning validation?

Hui Zhang: ‘The primary criteria of cleaning validation is visual cleanliness. In addition, acceptance criteria should be set up based on food safety requirements, like pathogens, allergens etc; or based on product quality requirement, like spoilage organisms, colour or other appearance attributes of the finished product etc.. It should be product-specific or product group specific, considering the worst-case product. From the operational point view, when people take the sample on the product contact surface after cleaning and disinfection, the acceptance criteria may be expressed as maximum limits for the amount of residual on the surface, for example in microgram per square cm for organic matter, or CFU colony forming unit per cm² for target microorganisms. When taking samples from the rinse medium after cleaning, the criteria may also be expressed as the maximum limits of residual in the ‘rinsing fluid’ for example in µg/mL for organic matter or allergens, or in CFU per mL from microorganisms etc..’


What are the differences between validation, monitoring and verification, and how do they relate to each other?

‘These three activities are intimately related with each other. Cleaning validation is a process of obtaining evidence that the cleaning program is effective and delivers consistently the predefined results when predefined cleaning processes are conducted. Typically, it answers the question: does my cleaning procedure work? Monitoring is performed during every cleaning procedure. It includes a planned sequence of observations, measurements, records of control parameters, to assess whether the cleaning procedure is performing within specifications. Monitoring activities are typically “real-time” measurements during cleaning, and it answers the question: is it working? Verification determines that the control parameters have been implemented as intended. Verification occurs during or after the cleaning procedure through a variety of activities, including observation of monitoring activities and review of records. Typically, it answers the question: did it work?


What are currently the main challenges with regard to cleaning validation?  

‘While everyone in the food industry agrees that cleaning validation is critical to guarantee the consumer safety and product quality, there is still a knowledge gap about how to conduct cleaning validation correctly and effectively.  Substandard cleaning validation may put the safety of our consumers at risk; on the other hand, taking an extremely conservative approach is also unnecessary, time consuming and creates impractical demands on resources.’


What is the scope of this guideline, what’s new and what is not included?

‘This guideline provides the overall concept, a master plan of cleaning validation. The Master plan is a structured approach with step-by-step guidance to complete the cleaning validation. Particularly, I would like to mention that this guideline provides a template of cleaning validation protocol and record, which is a new element in the EHEDG Guideline. We give clear instructions on how to use the template and what should be filled. I hope users can easily follow the protocol to establish their own validation, monitoring and verification programs. This guideline provides general advice and does not cover specific validation programs for a specific product.’


Is this guideline also valuable for big companies like Unilever that have their cleaning validation practices firmly in place? 

‘EHEDG is a great platform for companies to exchange knowledge and experiences with each other. All member companies can benefit from the extensive professional network of the EHEDG organisation, regardless of the business size. During the development stage of this guideline, we shared our practical experience with each other. After publication of the guideline, EHEDG will include Cleaning Validation in its training program and will help medium and small companies to build up their capability through training courses. After publishing this guideline, EHEDG will include the topic of Cleaning Validation in its training program to further support medium and small companies that want to optimise all of their cleaning validation processes.’