Cleaning of Food Plants – Science or Sorcery?

The scientific method as applied to the cleaning process within the food industry is more primitive than in management practice.  There are many reasons for this, and many reasons why this should not be so.  For some time salesmanship within the industry was experienced as a case of the ignorant selling to the innocent.  Salespersons were 9 to 5 operators with little or no experience of cleaning and a half knowledge of food legislation.  It was to their strengths that they played, snowing their customers under with paper that by implication suggested a professional approach.  This is not how the relationship between supplier and customer should be.  Therefore, rather than rehash all the pitfalls of poor hygiene etc, I would like to address the issue with regard to the type of relationship that should and could exist between cleaning supplier and producer.  I would also like to demonstrate by example how such an outcome can be attained, achieving into the bargain the goal of any cleaning regime – a clean plant.

To reach this end point it is however necessary to briefly describe the cleaning process.  Cleaning is the process of applying energy to a surface over a period of time in order to remove dirt and soiling.  Energy used may be applied in the form of: manual labour, mechanical energy, and heat or chemical energy.  Each form of energy can replace any other and produce the same result so the most economic form of chemical energy is normally used to replace manual labour and thus reduce the cost of cleaning.  The main chemical used is water, which acts in three distinct ways.  Firstly as a solvent, dissolving water soluble dirt, secondly as a medium of heat transfer melting fats like butter and lard which do not dissolve and lastly as a medium for transferring physical energy as in pressure washing or rinsing.  The rate at which water dissolves depends on the degree to which it is in contact with the dirt.  Water is a poor wetting agent and detergents are used to allow water to come in contact with and penetrate the dirt, speeding up the dissolving process.

There are many important points above but none more so than the fact that each form of energy can replace any other and produce the same effect.  This gives us some insights into the range of variables within the system.  So how do we optimise the cleaning process?  One thing is for sure as Juran’s often quoted comment states “if you always do what you always did you will always get what you always got” so change is necessary and none more so than the involvement of senior management.

But what can a company do to change? They can change their cleaning materials; they can even change their cleaning supplier.  You can focus on suppliers who provide you with realms of paper.  Providing you with magnificently produced cleaning schedules and brightly coloured material safety data sheets, all necessary but irrelevant.  Cleaning success is not a function of the volume of documentation supplied by a chemical supplier but the quality of his or her knowledge of the cleaning process.  Therefore a more systematic approach is required as demonstrated by the following example.  A food processing company had been on the merry-go-round as described previously.  They were frequently changing cleaning materials in an effort to improve the cleaning process.  Management decided enough was enough and committed to change.  The first item looked at was the cleaning material.  The company knew at that time product B was the most efficient material they had used to date.  Their initial request was to provide a more efficient cleaning product.

The project was undertaken and by analysing the most effective product to date, product C was designed from first principals.

To demonstrate the efficacy of C, a test was developed in conjunction with CAL Limited, an independent test laboratory.  The objective of which was to measure the quantity of Oils, Fats and Greases (OFG’s) remaining on the surface of a conveyor belt after cleaning.  Three products were tested and their efficacy compared, the greater quantity of OFG’s remaining on the surface, the poorer the efficacy.  In parallel a second test, in similar areas, was carried out using the Biotrace™ cleantrace swab method.  This test involved swabbing the cleaned area with a swab inserting the swab into a light measuring unit and obtaining a result in light relative units (rlu).  The higher the rlu reading the greater the soiling.  The objective of the second test was to compare both methods.  The results obtained were as per Table 1.

Table 1 – Results of cleaning – Oils, Fats & Greases analysis.

The results clearly demonstrate the efficacy of the product and the suitability of the Biotrace™ method for further testing.

The provision of a new product however was only half the story as the most efficient product in the world is still useless if used incorrectly.  This point was not lost on the company who now enlisted the supplier’s help to improve the process.  A second test was required to settle an argument between the supplier and the cleaning supervisor.  The companies cleaning supervisor suggested that hot water was required to rinse down the plant before application of the cleaning material.  The supplier disagreed, pointing out that at least half of the soiling comprised protein, which was water soluble but would denature if the initial rinse water was too hot and cling more tenaciously to the surface being cleaned.  The second test was carried out along the same lines as the first, with one site initially rinsed with cold water whilst the second was rinsed with hot.  Table 2 documents the results, and demonstrated to everybody’s satisfaction the most effective method of cleaning the said surface was with Product C prior to a cold water initial rinse.

Table 2 – Results of cleaning, post cold and host rinse.

The results as per both sets of tests were taken on board and a new set of procedures put in place.  Firstly the plant was rinsed with cold water under low pressure.  Secondly product C was applied to all surfaces and was allowed to act for fifteen to twenty minutes before rinsing away with hot water.  This method produced a clean plant and further enhanced the system a non-rinse sanitiser was applied to reduce any residual microbial levels.

In conclusion, the goal of a cleaning regime must be a clean plant.  Such a goal is a management prerogative and must be part of the management process.  Voluminous documentation and glossy brochures are irrelevant if the goal is not being reached.  Choose a supplier for his/her repository of knowledge and nothing else.  See cleaning materials for what they are, one variable within a system.  Do not forget that cleaning is your responsibility and finally, beware of snake oil salesmen.

Biotrace are the world leaders in rapid hygiene monitoring systems using ATP bioluminescence technology.  This technology provides the user with instant results verifying the efficacy of the cleaning process.  For more information contact:

Malcolm Bell,
Techno-Path,
The Rosse Centre,
Holland Road,
National Technological Park,
Limerick.
 
Tel: 061 335844
Fax: 061 203034

Paul Gannon is the owner and managing director of Gannon Chemicals Ltd and has been working in the cleaning industry for the past 20 years.  Specialising in detergent chemistry, he is a formulator/designer of cleaning products and a cleaning consultant to the food processing industry.  He holds a B.Sc. a post Graduate Diploma in Industrial Chemistry and an MBA.