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Chemical warfare

By John Dunn , 05-Feb-2010

Food firms should clean factories with caution and conscience. John Dunn reports

Glug glug. Most food factories do it. You open your bottle or drum of cleaning chemical, 'glug glug' it a few times into the bucket, top up with water and away you go mopping and scrubbing, blissfully unaware of how effectively or ineffectively you are cleaning your factory and how much it is really costing you. Doesn't anybody ever take any notice of the chemical manufacturer's precise dilution instructions? Hardly ever, it seems.

Philip Shaw is divisional director of Servest Pest Control and on the board of the Society of Food Hygiene and Technology. Previously he spent 10 years at Rentokil Initial as md of its specialist food factory cleaning division. "The biggest problem I've found is the misuse of cleaning chemicals," he says. The chemical supplier will say you need to dilute one part chemical to five parts water. But when the operative picks up the bottle they invariably give a 'glug glug' dilution. It is completely the wrong mix of chemicals for cleaning. Also, 'glug glug' is harmful for the environment because you end up with far too much toxic chemical in the drains."

One reason for following the chemical supplier's correct dilution is cost, suggests Shaw. The chemicals used for cleaning food factories are not cheap. "They are dearer than petrol. Some of the strong acid-type chemicals are very expensive indeed. If you 'glug glug' them, not only have you got the wrong dilution and the chemical does not do what it says on the tin, but instead of putting just 10p worth in, you have probably put £3 worth in. And that soon adds up over the whole factory. With 'glug glug' you are literally pouring money down the drain."

Most chemical suppliers offer automatic or manual dosing systems. The automatic systems generally use water flow to automatically mix the correct dilution. They are self-priming and give accurate and adjustable dilutions for a wide range of water flow. The manual ones use a simple hand pump to squirt a measured dose into your container. Provided the operative has been trained in how to use these pumps, there shouldn't be a problem, says Shaw. However, these dosing meters cost money. And some food manufacturers won't purchase them and happily continue with their 'glug glug' mentality, he warns.

Simon Bishop also sees too much 'glug glug'. As founder of factory hygiene consultancy, Technical Management Solutions, Bishop says there is a general lack of understanding about the use of cleaning chemicals in the food industry. "You will often find someone saying: 'I'll put an extra 10% in because it will give me 10% more effectiveness.' But the chemical companies have spent millions of pounds developing these products and these firms will tell you the right dilution to use, based on science and trials."

 

Heart of the problem

The heart of the problem, suggests Bishop, is that food factories don't see cleaning as an added skill for their workforce. "Most UK food companies employ their own cleaning staff, with the exception of the ambient sector such as bakeries. A bread plant, for example, is dusty, often has high roofs where access is difficult and is complex, making it hard to clean. So specialist cleaners are generally used. But in general I believe cleaning should be maintained in-house, with companies creating a skilled labour resource to do it." However, getting the right labour resource in cleaning can be a problem, says Bishop. "Generally in the food industry cleaning staff have to work nights or weekends and the pay is not great. So the skill-set and the labour pool that you can call upon to get your cleaning staff is not always the best."

So you need to treat and train your cleaners as key skill operatives, says Bishop. "These people are using chemicals; they are taking machinery apart; they are being asked to work to a number of standards. If you just treat them as someone with a mop then you will get what you pay for someone with a mop. But if you have six people who are trained and 10 people who are not trained, then the six people who are trained will do a better job than the 10 who aren't. And you can use the money saved from the 10 people to pay the six people."

The other problem with cleaning, says Bishop, is lack of planning. "People completely underestimate the time it takes to clean. I worked on a project where the cleaning staff wrote into their cleaning procedure the number of man-hours needed to clean each machine. It is paying dividends now because they can justify how long it takes to clean the factory and if any of those hours are taken away, the factory will not be clean. Planning of cleaning is really critical in the food industry. You must plan for the number of hours you need and those hours should not be negotiable.

"Quite often when I go to a factory, they don't know what a properly clean factory should look like. I have to tell them: 'This is how I want it to look every day.' Also, says Bishop, engage a chemical provider a good one and use their advice. They know best. Also, there is help available from organisations such as Campden BRI which has written a comprehensive guide to factory cleaning (Guideline 55. Cleaning and disinfection of food factories: a practical guide).

 

Science of food fouling

But if 'glug glug' is not your cup of tea and you really want to get to know the science behind food fouling and why your machinery gets dirty and how you can clean it properly, then pop along to Jesus College, Cambridge on March 2224 for the fourth international congress on Fouling and Cleaning in Food Processing 2010. The aim is to bring researchers and industrialists together to hear the latest developments in understanding food fouling and how it can be cleaned off more effectively.

There are several reasons for the continuing international search for better ways to clean off food fouling, says Dr Ian Wilson, congress secretary. "One is to know exactly when your system is clean because most of what we are talking about here is cleaning-in-place. You don't really want to have to open a machine in order to check that it is clean. So there is on-going research into developing sensors and assurance techniques to make sure that equipment is clean without having to open everything up."

Another issue for the food industry, says Wilson, is the cleaning of multi-purpose processing plant which process lots of different food materials. "Sometimes you have to process something completely new which means you have to work out what is the best way to clean it, because it is almost certainly going to foul up. So there is a lot of interest in looking at the material science of food products to come up with faster cleaning solutions, rather than spending months on trial and error." It is the chemical equivalent of rapid prototyping used in engineering industries, says Wilson, where a one-off prototype part is built up directly from the computer data used to design the part. Birmingham University's chemical engineering department, for example, has now drawn up a 'cleaning map' that classifies food soils according to whether they are based on starch, sugars, proteins and brewery deposits. It then gives the best removal conditions based on the physical properties of these spoils. The work is part of the government-funded project ZEAL (Zero Emissions through Advanced cLeaning) led by Birmingham and including Cadbury, Unilever and Scottish & Newcastle.

But then there is a whole other world of bacteria and food contamination. In particular, says Wilson, the congress will be looking at how surfaces used in the food industry can either exacerbate the problem of bacterial attachment or in fact reduce it. "What is a non-stick surface for one bacterium is not necessarily non-stick for another. You know bacteria as soon as you find that one of them doesn't stick to a surface, along comes another one that says: 'Oh, I like this.'"

 

Titanium surfaces

Part of the problem, says Wilson, is that everyone is happy with stainless steel. "It is certified. You can sterilise it. And all the hygiene and cleaning codes are set up for stainless steel." But recent work at Manchester Metropolitan University, for example, has shown that titanium could be a better work surface than stainless steel. Abrasion, cleaning and impact damage all increase the surface roughness of food work surfaces and researchers at Manchester Met are looking at the way different work surfaces harbour bacteria. They have found that titanium could work much better than stainless steel because some pathogenic bacteria such as E.coli find it more difficult to attach themselves to titanium. This will lead to new designs of food work surfaces that are easier to clean, they suggest.

But what if you could use a basic surface and coat it with a substance designed to kill specific bugs? The surface would disappear after a while but then what if you could clean it or recoat it with a lacquer, wonders Wilson. "Some people in the dairy industry are now looking at so-called temporary or sacrificial coatings," he says.

 

Key Contacts

Campden BRI 01386 842000

Ecoclean (Servest Group) 01284 703535

Fouling and Cleaning in Food Processing 2010 01223 334791

Society of Food Hygiene and Technology 01827 872500

Technical Management Solutions 07908 232095

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