This article features otherwise unpublished food safety management data held by BRCGS and Safefood 360° which, combined with real-time events, provides an unparalleled view of current and emerging issues and trends in the food safety industry.

 

The principles of cleaning and disinfection

Cleaning and disinfection of equipment, surfaces and environments are fundamental components of good manufacturing and hygienic practice in the production and preparation of foods. The Codex General Principles of Food Hygiene defines cleaning as ‘the removal of soil, food residues, dirt, grease, or other objectionable matter’ and disinfection as ‘reduction by means of biological or chemical agents and/or physical methods in the number of viable micro-organisms on surfaces, in water or in air to a level that does not compromise food safety and/or suitability’. The historical definitions of cleaning have generally focussed on the need to manage microbiological risk but the importance of cleaning in the context of other hazards and, in particular, reducing allergen risk has been the focus of much attention in recent years.

The requirements for cleaning and disinfection are included in national legislative frameworks and industry guides for good manufacturing/hygienic practice, including:

  • United States Food & Drug Administration (USFDA) Code of Federal Regulations 35
  • The European Union (EU) Regulation on the Hygiene of Foodstuffs No 852/2004
  • Food Standards Australia New Zealand Food Safety Practices and General Requirements Standard 3.2.2
  • Industry guidelines such as UK Hospitality Industry Guide to Good Hygiene Practice and Food Industry Guide to Good Hygiene Practice: Retail

 

Effective cleaning and disinfection are control measures in a HACCP-based (hazard analysis and critical control point) food safety management system but, unlike critical control points, they are referred to as prerequisite programmes (PRPs) as they are more generic in nature and often apply to many areas in a process.

 

Equipment design, chemicals, method and utensils

A number of principles are fundamental to effective cleaning and disinfection including the design of the equipment and environment, the choice of chemicals, the method of cleaning, and the cleaning tools and equipment used for the purpose. Validation of the adequacy of cleaning and disinfection, together with ongoing verification of the efficacy, are key to achieving a successful outcome.

The design of equipment and environments is essential to the hygienic production of food, not only in the ability to clean and disinfect them but also to operate in a way to reduce the risk of build-up of microbial, chemical, physical and allergen hazards. The European Hygienic Engineering Design Group (EHEDG) offer a number of excellent texts supporting the principle of hygienic design, and for those interested in a basic introduction to hygienic design principles, there is a simple, free video produced by CampdenBRI on the topic.

Cleaning chemicals and disinfectants, as well as the method and equipment to be used, need to be chosen carefully and this should be conducted by individuals who have expertise in this area. This is because many chemicals are not suitable nor effective at removing certain foodstuffs from surfaces due to fundamental incompatibility with the food or the surface. In addition, some chemicals may not be safe for manual use and may only be suitable for automated clean in place (CIP) systems. A number of useful texts and videos are available describing the principles underlying the mode of action and compatibility of different cleaning chemicals and disinfectants/biocides.  Expertise can also be sourced from one of many reputable, cleaning chemical service providers (Diversey, Ecolab, FoodClean, PHS). In addition to the different chemicals, there are many different methods of cleaning and disinfection that may be employed for different circumstances such as surfaces, air, equipment and the environment. The choice of equipment to be used is also important both in terms of their ability to access areas to be cleaned and storing, maintaining and cleaning/disinfecting them such that they do not become sources of contamination in their own right. The selection and management of specialist vendors of such equipment and utensils is as important as the choice and use of critical raw materials for the production of safe, quality food (Vikan, Klipspringer).

The generally accepted approach to manual cleaning and disinfection of equipment and environments, other than those that are intended to remain dry i.e. low moisture foods, is to:

  • Remove gross debris
  • Rinse with water to remove residues
  • Apply a detergent (at the correct concentration) to remove protein, fats and other food adhering to the surface
  • Scrub the surface with suitable equipment/utensils
  • Rinse with water to remove detergent
  • Inspect to verify efficacy of cleaning
  • Apply disinfectant (at the correct concentration) and leave for the specified contact time
  • Rinse with water, if applicable
  • Test to verify efficacy of cleaning and disinfection

 

There are many variations to this depending on the individual circumstances pertaining to the equipment, environment and the food matrix. For example, some foods and processes result in high amounts of organic debris build up, some have high fat content, others have a propensity for scale build up, and many suffer from a combination of all these properties and more. Different process equipment and surfaces present considerably different risks regarding harbourage points where food can become trapped and where microbial, chemical and allergen cross contamination risks are created. Indeed, even without entrapment points, poor cleaning and disinfection can result in microbial biofilms that build up over time, compromising the safety and quality of the product.

Different cleaning and disinfection regimes operate for clean in place (CIP) systems. The removal of operator exposure means that higher flow rates/pressure and temperatures can be used, which is helpful for greater efficacy. Likewise, for low moisture products where the presence of water can introduce significant risk of microbial proliferation, dry cleaning techniques using physical removal of product and alcohol-based disinfection, is often employed between the period for full wet cleans.

Notwithstanding the many different combinations of approaches to cleaning and disinfection, once a method is established it must be documented into a cleaning instruction or schedule. This needs to be clearly documented, easily understood, and those undertaking the cleaning should be properly trained. Most chemical or hygiene service providers will generate cleaning instruction cards for clients or provide them with proformas to undertake this task and a useful video on this is available. In addition, many IT based food safety management solutions also include provision for documenting the cleaning instruction, schedule and provide a means to record compliance and verifications checks such as Safefood360°.

Allergen cleaning

It is important to recognise the critical role that cleaning plays in managing risk in relation to allergens. All the same principles apply but in the case of allergens, it is the nature of the residual allergen component that presents the risk, rather than the presence of residual nutrients and/or micro-organisms. Thus, the design of equipment and surfaces, the choice of chemicals, the method of cleaning and the utensils/equipment used for cleaning are all similarly important. These considerations were reviewed in a recent LGC Assure Newsletter on Free From Foods, in a specific video on cleaning and control of allergens, a blog on colour coding of cleaning equipment and with a very helpful interactive factory map on allergen risk management.

 

Validation and verification

Establishing the efficacy of cleaning for the removal of allergens, and cleaning and disinfection for the removal of micro-organisms, is key for the safety and quality of the food. Basic validation and verification is often accompanied by visual assessment post cleaning to ensure that there are no signs of visible food debris left on equipment or surfaces. However, visual techniques are not sufficient to establish the presence of residual amounts of allergens or micro-organisms and therefore, validation and verification using analytical techniques is essential. Validation is carried out under controlled conditions where known initial contamination levels on the equipment (allergens or micro-organisms) are subject to the cleaning/disinfection regime that will be employed during routine hygiene operations. Swabs of surfaces, rinse water and product are taken before and after cleaning/disinfection and the presence and/or level of the target micro-organism/allergen is determined. Cleaning and disinfection can be optimised through the use of effective validation. Thereafter, routine verification should be employed to check that cleaning and disinfection remain effective through the use of similar testing or by the use of rapid tests for specific hazards or indicators. For example, rapid tests are available for most of the key allergens to verify cleaning efficacy and rapid indicators of the presence of food residues on surfaces e.g. protein, ATP and A3 can also usefully serve as part of cleaning verification.

 

People

Training in food businesses is often focussed on fundamental hazards and controls such as micro-organisms, chemicals, allergens, or broad principles such as HACCP and risk assessment. However, a detailed understanding of cleaning and disinfection for the control of such hazards should be considered a foundation stone in the education of food business employees, whether in technical or production roles. Training can often be sourced from the chemical/hygiene service provider e.g. Diversey, CampdenBRI, Kersia, Christeyns.

 

Third-Party certification

Cleaning and disinfection procedures, including the design and maintenance of equipment and the environment, are key components of voluntary third party assurance standards such as the BRCGS Global Standard Food Safety and other GFSI recognised certification programmes. In addition, the safe management of chemicals is also an important element of such standards. A key benefit of these standards is the insight that can be drawn from the review of collective audit data and, in particular, non-conformities. A review of the non-conformities arising from audits to the BRCGS Global Standard Food Safety Issue 9 since its implementation in 2023, highlight hygiene including cleaning and disinfection, amongst the top 10 non-conformities, accounting for almost 20% of all major and minor non-conformities.

 

This brief exploration of cleaning and disinfection aims to provide you with some helpful insights in your food safety assurance journey. Please do explore some of the links provided as there is a wealth of help and assistance out there to support you in the delivery of safe, high quality foods.

Other useful reference sources regarding cleaning, disinfection and general good manufacturing practices:

   

Author

 

Alec Kyriakides

BRCGS International Advisory Board Chair

Independent Food Safety Consultant