ABC’s of Manual Cleaning - Part I: Why is it important?

This blog series will go over the various ins and outs of manual cleaning and why it is necessary for the safe production of food. It is essential for food processors to understand that the proper selection, use, cleaning, storage, and care of tools employed can prevent or minimise cross-contamination of food from hazards that are of a public health concern, e.g., microorganisms, allergens, and foreign materials.

Cleaning and disinfection of environmental surfaces (both food-contact or non-food contact) and food production equipment can be a time-consuming operation in food facilities. Nevertheless, the maintenance of sanitary conditions to ensure product safety and quality is a regulatory, industry, and global food safety standard requirement.

In 2015 the WHO estimated that more than 23 million people in Europe fall ill from eating contaminated food every year, resulting in 4654 deaths¹. The use of contaminated equipment and utensils is one of the top 5 contributing causes to foodborne illness outbreaks².The key food safety hazards of public health concern are bacterial pathogens, allergens, chemicals, and extraneous foreign material – and consequently, cleaning methods and equipment capable of minimising the risk of these hazards are required.

Industry cleaning methods may range from being process-specific (e.g., clean-in-place [CIP] for cleaning processing pipework and closed vessels) to the much simpler, process-agnostic manual cleaning involving the use of brushes, scrapers, squeegees, etc.

Automated cleaning isn’t always fool proof

In contrast to manual cleaning, CIP normally involves the automated cleaning of equipment parts, such as the interior of pipes, vessels, or fittings without disassembly. This is generally done by pumping chemicals at a set concentration, temperature, and pH through the system, for a controlled period, at a flow rate that generates turbulence, which provides the mechanical action required as part of the cleaning process in a closed system. Clean-out-of-place (COP) involves disassembly and removal of parts to a remote automated cleaning system.

Once all the cleaning parameters used by these automated systems have been determined and programmed in, cleaning is as easy as pressing a button. However, the biggest limitation of CIP and COP cleaning is that the poor hygienic design of some equipment and surfaces, e.g., the presence of narrow, inaccessible spaces, or dead-end zones that allows contaminants to get trapped and be difficult to remove, doesn’t always allow for a thorough clean using the automated method.

 
CIP components, like spray balls; and the valves, couplings, and sampling ports of CIP cleaned processing pipework also require regular disassembly and manual cleaning, to ensure the on-going efficiency and effectiveness of the CIP clean.

Clean before you disinfect

If food equipment and surfaces aren’t cleaned properly, certain microorganisms may survive and persist by secreting a slimy, extracellular polymeric substance that can enmesh other organisms, nutrients, moisture, and foreign materials to form a biofilm that can firmly attach to a surface. According to Moorman and Jaykus (2019), manual cleaning is important for surface biofilm removal because “one just can’t sanitize one’s way out of a persistent biofilm problem within a facility. Biofilm eradication, therefore, generally requires equipment teardown, deep-cleaning and sanitation, and a follow-up verification.” ^3,4

Proper cleaning of equipment and surfaces, therefore, is the first step toward better overall sanitation in food processing plants. Debra Smith, Vikan’s global hygiene specialist, clearly demonstrates the importance of manual cleaning action and the use of cleaning detergent and potable water to significantly reduce surface biofilm load rather than simply immersing a dirty piece in a chemical solution⁵. Disinfection only follows appropriate cleaning and rinsing of the surface.

In a nutshell, applying detergents and disinfectants alone cannot make a fundamental difference in removing surface biofilms. Manual cleaning will always be required, in addition to other cleaning methods, because there will always be hard-to-reach places where biofilms can form and only be effectively removed through manual cleaning.

Selected References:

1. WHO (2015) estimates of the global burden of foodborne diseases: Foodborne diseases burden epidemiology reference group 2007-2015.
   Link: https://apps.who.int/iris/handle/10665/199350
   
   
2. Top5CDCRiskFactorsContributingFoodborneIllness.pdf (sbcounty.gov)
   
   
3. Moorman, E., & Jaykus, L. A. (2019). Impact of Co-Culturing with Pseudomonas aeruginosa on Listeria monocytogenes Biofilm Physiochemical Properties and Sanitizer Tolerance. In IAFP 2019 Annual Meeting. IAFP
   
   
4. Remco (2020). The Role of Manual Cleaning in Biofilm Prevention and Removal. Whitepaper Link: https://go.remcoproducts.com/biofilms
   
   
5. Vikan (2020). Biofilm Demonstration Workshop. Video Link.