Protection of the Whole Bottling Plant Environment

Watercoolers with anti-microbial surfaces are a technological advance, but it would be an even greater advance if your whole bottling plant could be treated in a like manner. 


This is not as far-fetched as it seems, in fact, such a treatment is already available. In previous publications I have talked about airborne bacteria and transference of bacteria from one surface to another, by hand or by contact with contaminated clothing or gloves. A surface treatment for floors, walls and ceilings is available which creates an anti-bacterial coating.


The procedure involves cleaning the surfaces thoroughly and then spraying a solution of the active component onto the cleaned areas. After drying, the film hardens and the anti-bacterial surface is fixed. Normal cleaning products will not remove the film.


Previous applications have been in hospital environments, but the application in food and beverage preparation areas is a natural next step. The biocidal elements do not leach out of the film therefore safety, toxicity and taint are not issues.


The treatment is ideal for new bottling plants before commissioning , but post application is equally valuable. 

E. coli in the Bottling Plant

The recurring news items about E. Coli infections in the UK and Continental Europe show how contaminated food distributed to the general public can have disastrous consequences, not only for the unfortunate people affected but also for the food supplier.


E. Coli is found in animal intestines and contamination can occur easily in the abattoir during the disembowelling process. It can be prevented by good cleaning and disinfection programmes.

Fortunately, in the bottled water industry such contamination is rare because of the strict hygiene practices required. However, bottling plants on farming land do carry a higher risk. I know of one bottling plant which is adjacent to an abattoir so that extra hygiene precautions need to be taken.

Most contamination in the bottling plant is either walked in on footwear, floated in through doorways or transferred by human contact. Floors are particularly susceptible and it pays to use a disinfectant with residual action so that protection is maintained for extended periods during the shift.

Disinfectants based on quaternary ammonium compounds provide this residual action and are specially suited for treatment of walls and floors. It is advisable to use two different types of disinfectant in long-term treatment of floors, to prevent any possibility of acclimatisation by microorganisms. A chlorinated foamer is ideal as a companion product. 

Meanwhile, despite the bad image of the bacterium, E. Coli can look quite attractive and photogenic, as this picture of an unusual swimming variety shows.

Hand Hygiene

Hand hygiene is a key factor in ensuring that bacterial contamination stays out of your bottling plant and cooler servicing room.


Facilities must be available for washing hands, with easy access, warm water and a sink area that is easy to keep clean. A supply of paper for drying hands and a box of protective gloves must always be nearby. Hand  washing should become a ritual whenever an operator or visitor enters the plant. 


Two products are required next to the sink - a liquid soap and an alcoholic gel. The operator washes hands thoroughly first, then dries with a paper towel and finally applies the alcoholic gel. The gel should be of the type which dries quickly without leaving any odour or residue. 


Protective gloves are no substitute for hand washing and hands should be clean and disinfected before wearing gloves. The gloved hand should be treated with alcoholic gel at regular intervals to offset contamination arising from accidentally touching the face, hair or items of clothing.

Physical Contamination of Bottled Water

We all know that most foreign bodies get into 19L bottles at the customers’ premises, normally when the bottle is empty, and then the bottle is hijacked for other purposes.


It is very rare that objects enter the bottle in the bottling plant, but it can happen, the most obvious items being human hair and insect fragments. Protective clothing needs to be worn to protect the water from contamination. Over-clothing should be without top pockets and designed to completely cover the upper body. Hair protection needs to be worn so as to completely cover the hair. Disposable hair covering should be changed daily.


Hair covering should be put on before coats and taken off after coats to prevent hair falling on shoulders. An adequate non-glass mirror should be available to enable staff to check that their hair protection covers 100% of their hair.


Electric fly killers should not be positioned close to the filling section to avoid insect fragments being spattered into this area. The design of the fly killer should be such that most of the debris falls into a catchment tray. An alternative is to consider a UV based non-electric killer with a glue board.


Make a study of glass in the bottling plant and assess the risks associated with breakage. Remove all unprotected glass and replace with a suitable glass alternative or protect with shatterproof film. Ensure that a glass breakage  procedure is in place and that it will be immediately implemented if a breakage occurs.


Light fittings should all  have unbreakable diffusers or covers (not glass), and where fluorescent tubes are fitted the diffusers should have covered ends. Shatter-proof fluorescent tubes are available as an alternative to using covers. Where possible, light fittings should be flush with the ceilings.


Watch out for fragments of bottle caps. The bottle washer is usually littered with cap fragments at the end of the shift. The likelihood of fragments getting into the filler section is remote, but ensure that cap debris are cleared out of the machine regularly.


A more risky point is during capping. Make sure that the capper is well adjusted and that the caps are completely compatible with the neck dimensions. If some caps are incompletely seated, dissuade operators from bashing them with a hammer, this may cause some plastic bits to fly off into the water.


As mentioned at the beginning, the likelihood of foreign bodies getting into the water is remote, and with good housekeeping practices probably it will never happen. However, it is important to be aware of all the hazards that may lead to this unlikely event.

Sanitising Pipework and Holding Tanks in Bottling Plants

Water is best kept in constant flow from source to filling. Water for bottling, natural mineral water in particular, should not be retained in static bulk storage for more than 24 hours.


The design and operation of the storage tanks should restrict the time from abstraction to bottling to a minimum. Air entering the head space of tanks should be filtered or treated to prevent contamination of product water.


Water is the world’s best solvent - it will dissolve or absorb all manner of substances. It is therefore highly vulnerable to picking up taste and odour taints. It is well worth using stainless steel, grade 316, for all pipework, tanks and bottling equipment.

In the case of product which has not been treated or disinfected, eg natural mineral water, great care must be taken to prevent microbial contamination and pollution. Cleaning of tanks and pipework deserves careful attention.  Alkaline or acidic CIP cleaners are ideal for cleaning and descaling closed systems and terminal disinfection is best carried out with peracetic acid or, alternatively, hydrogen peroxide.

How to Prevent Corrosion in Bottle Washers and Coolers

Corrosion of stainless steel parts in your bottle washer, or in watercooler reservoirs, is something that you may not have considered. In fact, if good quality stainless steel is used, there should be few problems. However, in certain circumstances problems may arise.

Acidic products are used for descaling bottle wash equipment and watercooler reservoirs. Selection of the correct acid is important in a spring-water or mineral-water environment because the scale comprises salts from the water. The salts which potentially can be involved in corrosion are the chlorides. If the correct acid is used, for example phosphoric acid, there should be no problems, but if certain other acids, such as nitric acid, are used there is a grave danger of corrosion, leading to perforation in the worst cases.

The picture shows a microscopic image of stainless steel after exposure to nitric acid and chlorides. The preferred acid to use is phosphoric acid. In all applications of acidic products it is always recommended to rinse thoroughly after use.

Chemicals in Drums or IBCs?

If you order large quantities of bottle wash detergent, you may wish to consider delivery in IBCs (Intermediate Bulk Containers) rather than drums.

This has several advantages, for example, the cost per litre is lower since you are no longer paying for all those drums. From an environmental viewpoint, you do not have to dispose of plastic containers because empty IBCs can be removed for re-use without any additional cost. The other issue, however,  is how to transport the product to your bottle washer.

You may prefer to keep refilling a drum from the IBC, although a better method is to install automatic dosing. This will enable you to add the initial charge and continue to top-up throughout the day automatically. There will be fewer handling operations and this will create enhanced operator safety.

Top-up can be done using a timer or a conductivity loop, where additional product is added only when the conductivity falls below a certain level.

How to Prevent Green Algae in Bottles

In the summer months, there is always an increase in numbers of green bottles being returned for washing.  Once green bottles enter the washer, this can lead to contamination of all other bottles during the washing process.  Unfortunately, the storage of full and empty bottles by the customer is not always ideal, but with a few simple precautions, it is possible to reduce the incidence of green bottles.

Algal spores are everywhere in the environment and they can be carried easily by the wind.  With sunlight, warmth and moisture, algae can grow quickly and soon become visible in the bottle.  Empty bottles, if stored outside, must be covered with black or dark plastic wrappings and not left outside for more than seven days.  Filled bottles should not be left outside for more than 24 hours and never in direct sunlight.

Customers should be advised on best storage places, for example avoiding direct sunlight at windows, and keeping empty bottles away from dusty environments.  Regular collections should be made to avoid prolonged exposure of empty bottles.

Checking bottles before washing should be done thoroughly and diligently, badly contaminated bottles should be discarded.  Bottles with small amounts of algal contamination should be pre-washed with oxidising products before entering the main washer.  Older bottles have more tendency to suffer from algal growth. This is because of the presence of micro-cracks, which create a refuge for spores during the washing process. Micro-cracks are a result of stressing the polycarbonate through transport and too many wash cycles.  Older bottles should be discarded and recycled.

Preferably use a wash detergent containing a disinfectant component and ensure that the wash temperature does not fall below 60 degrees C. At the end of the shift,  the washer should be thoroughly disinfected with a suitable material such as peracetic acid.  

How to Remove Biofilm

The attachment of bacteria to a surface and the development of biofilm can be viewed as a survival mechanism. Bacteria benefit from capturing nutrients from the water and developing protection against disinfectants. Potable water, especially high purity water systems, are nutrient-limited environments, but even nutrient concentrations too low to measure are sufficient for microbial growth and reproduction.

How does life in a biofilm help bacteria acquire nutrients? Trace organics will concentrate on surfaces; extracellular polymers will further concentrate trace nutrients from the bulk water; secondary colonisers use the waste products from their neighbours; by pooling their biochemical resources, several species of bacteria, each armed with different enzymes, can break down food supplies that no single species could digest alone.

Biofilm bacteria may be 150-3000 times more resistant to biocides than free-floating bacteria. In order to destroy the cell responsible for forming the biofilm, the disinfectant must first react with the surrounding polysaccharide network. The cells themselves are not actually more resistant, rather they have surrounded themselves with a protective shield. The disinfectant’s oxidising power can be used up before it reaches the cell.

In fact, biofilm bacteria often produce more exopolymers after biocide treatment to further protect themselves. It is important therefore to choose the correct disinfectant and to apply it in the correct manner. A constant application of disinfectant at low strength may actually encourage biofilm growth. Disinfectants based on hydrogen peroxide synergised with silver ions are effective against biofilm.  With synergised hydrogen peroxide, the active oxygen arising from the peroxide destroys the biofilm, thus enabling the trace silver components to destroy the bacteria or viruses unhindered.

Biofilm build-up in drains within the bottling plant can cause bad odours and requires a flush through with peroxide to destroy the biofilm and kill odour-causing bacteria. The breakdown products from the peroxide are harmless and can actually benefit surface water by oxygenating the effluent.

Certain other disinfectants are also very effective against biofilm, namely peracetic acid and chlorine dioxide. Peracetic acid works well even at low temperatures, e.g., around 5 degrees C. Chlorine dioxide is highly effective and is recommended for CIP (Cleaning in Place) disinfection programmes.

Exploding 19L Bottles

I have written previously about foreign bodies in bottled water and occasional misuse of 19 litre bottles. I was amazed to find out that the bottles are often used in chemistry experiments in schools to demonstrate dangerous reactions between various substances and water.

The picture, taken from a chemistry journal, shows the violent reaction resulting from the addition of metallic sodium to water. You may remember this demonstration from your school days. While I understand that this is a safer option than an open dish, it is not setting a good example. Do not try this in the bottling plant!