Hand Hygiene and Glove Failure

I read some disturbing information about hand washing recently.  From various surveys among the general public in the UK, it transpires that 31% of men and 17% of women did not wash their hands after using the toilet.  58% of those that did wash their hands used water without soap.  26% of men and 17% of women do not wash their hands before preparing food.

Wearing gloves can lead to a false sense of security.  A further survey showed that with vinyl gloves, 34% allowed bacteria to penetrate and 53% failed in use.  With latex gloves, 20% allowed bacteria to penetrate and 3% failed in use.

This highlights the importance of hygiene training for new recruits in the bottling plant. Make sure that hand washing facilities are well placed and in good working order, with provision of soap and means to dry the hands.

Bactericidal hand soap is recommended for washing followed by alcoholic gel for hand disinfection.  These should be dispensed from hands-free dispensers.  A thorough hand-washing regime is essential whether or not gloves are used.  New glove materials are available which combine the flexibility of latex with the strength of nitrile.

To avoid any transfer of bacteria from touched surfaces, long-lasting disinfectant sprays are available which may be applied to door handles, plastic curtains and surfaces in toilet areas.

Washing Polycarbonate Bottles

I am sure that you are all aware of the factors involved in providing a clean bottle.  These are chemical type, concentration, temperature, physical agitation and time.  However, there is another factor of importance and that is compatibility of bottles with your washing process.

Apart from excessively high temperatures, the factor most likely to affect bottle compatibility is the type of chemical used.  The formulation must be balanced to give good cleaning and appearance with no streaking and maximum bottle life.  Unless the chemical has been specifically formulated for polycarbonate washing, it is likely that problems will arise eventually.

High alkalinity can be the worst offender, but careful formulating will offset the effects of causticity and produce an excellent clean without causing bottle damage.  One of the key ingredients in doing this is the detergent.  By "detergent" I mean a real detergent, not just a mixture of alkali and water softener which is characteristic of many products on the market.  By careful selection of detergent, the bottle will receive protection from the effects of the alkali and, as a bonus, will aid draining and reduce carry over.  If your product does not generate a measured level of foam, it does not contain a detergent.

If your supplier has formulated correctly, he will have carried out compatibility checks on polycarbonate.  The testing involves putting polycarbonate strips under stress by bending and then immersing them in neat product.  The kind of results we obtain are shown in the photo.  This product was highly alkaline with no protection.

You may say that bottle lifetime is not a real concern.  However, there is another, more insidious, factor and that is the formation of microcracks.  These may not be so obvious, but they are breeding ground for bacteria, algae and other undesirables and these bacteria will only emerge after the bottle has been filled for some time, unfortunately when the bottle is with the customer.  Bottle compatibility is therefore important in providing the highest quality product.

Chlorine Dioxide Disinfection and Water Treatment in the Bottling Plant

Chlorine dioxide has been used for treatment of drinking water for many years. Application in the bottling plant for treatment of the water is fairly common and use as a disinfectant for water-contact surfaces is increasing.

Ozone has been used classically for terminal disinfection in the bottle washing process or as treatment of the final rinse water.  Treatment of the water itself is also common despite several disadvantages. These are predominantly the high cost and tendency to create damaging bromates and ketones. 

Chlorinated disinfectants have been used for treatment of water, but in the bottled water industry this is avoided, to prevent formation of halomethanes and haloacids, both of which can produce a taint in bottled water. 

Chlorine dioxide is quite different and does not have the disadvantages of other chlorine-containing compounds. Chlorine dioxide is a gas which dissolves easily in water. The breakdown products are chlorides  which are used by the body in several natural metabolic processes.

Chlorine dioxide is excellent in removing biofilm and is often used in the health care sector for this reason. Application in the brewing industry has been known for many years. What are the applications in the bottling plant?

There are different ways of generating chlorine dioxide.  For automatic and continuous use, the gas is generated by a chemical reaction between two materials which are automatically monitored and mixed. On a cost basis the initial outlay and running costs are much less than using an ozone installation.

                                Chlorine Dioxide Generator for Bottling Plants

For treatment of pipe work and other water-contact surfaces, it is possible to generate the chlorine dioxide manually by mixing a chlorate with a suitable acid and using the mixture immediately. However, stabilised forms of chlorine dioxide are available which remain stable for extended periods if stored correctly.  Several stabilisation systems are used, many relying on careful control of pH.

Chlorine dioxide sources in tablet form are also available, useful for disinfecting water coolers.

Airborne Bacteria in the Bottling Plant

I have written previously about the dangers of airborne bacteria and their role in causing many cases of bottled water contamination.

During production, with efficient positive pressure airflow, this should not be a problem. However, during the night and at the weekend, bacteria, dust, pollen particles and mould spores will settle on your washer, filler, cap chute and other objects in the plant. Start up can therefore be a vulnerable time for your operation.

An effective solution uses UV-C technology to destroy airborne micro-organisms. Untreated air is drawn through a particle filter, removing dust and pollen particles. The air then passes over a 36W compact UV-C tube positioned within a baffle chamber.

This chamber prevents any UV-C light escaping the unit, whilst ensuring all the air drawn in passes over the tube. Treated air is then expelled out of the unit.

The unit has been independently tested to prove its effectiveness against the most common airborne bacteria, yeasts and moulds.

More recently, high tech devices have appeared on the market using cold plasma technology which effectively destroys micro-organisms in the air by generating transient oxidising chemicals.

Hygienic Design of Bottling Plants

One of the observations I have made in visiting many bottling plants, is the wide variations in machine configuration and location. The design of the plant environment is important in maintaining good quality water and avoiding contamination problems, in particular around the bottle washer and filler.

It is important to keep the bottle washer, and particularly the filler, enclosed and protected from the outside environment as much as possible. One enigma in all this is that you are introducing dirty bottles into an area that you want to keep clean. This is where configuration of the machine is important.

The incoming dirty bottles should be kept away from the filler. Some configurations are not ideal particularly where the conveyor carrying dirty bottles passes close to the filler. The bottles are often covered in dust and I have seen operators occasionally wiping dirty bottles with a cloth before loading the washer. This causes dust to fly around. 

The fork-lift truck and conveyor loading area is often separated from the washer by plastic curtains, which is not best practice. The washer and filler should never be in an open area with open access to other areas such as warehousing.

If plastic curtaining is used, it must be kept clean otherwise bacteria can build up rapidly. Positive air pressure should be maintained in the bottling plant room, or if that is not possible, within the machine itself. 

Access to the bottling plant should be restricted to essential personnel. Preferably white boots, coats, hats and protective gloves should be worn in the plant. The latter should be changed regularly or disinfected with an alcohol gel.

Bottle Washing in Cold Water?

In talking with bottling plant supervisors, one of the concerns has been how to safeguard against plant malfunctions.

For example, if the heater is on the blink and you cannot reach the desired temperature of 62-63 deg C, what do you do - stop production, battle on at a lower temperature and keep your fingers crossed? What do you do if the ozonator starts to play up - stop production immediately?

Plant operators have been asking for some kind of safety net or second line of defence when these things happen. In fact, there are bottle wash products available that will help address these issues.

If the bottle wash product contains an additional disinfectant component, the value of this will come into play when things start to go wrong.

The disinfectant component has to be approved for indirect food contact and not interfere with the cleaning performance. In the event of an equipment malfunction, the concentration of the product may be increased to  give an additional sanitising safeguard.

It could be ideal for those who have no alternative but to wash in cold water. The degree of additional sanitising may be adjusted simply by increasing the overall concentration as required.

Sanitising Wipes and Sprays for Cooler Servicing

A lot depends on how you want to use wipes and some users prefer a cleaning/disinfecting wipe rather than a purely disinfecting wipe.

If the wipe is to be used for sanitising watercoolers, there can be problems in effectively treating tap areas simply because it is difficult to get into the tap. Sprays, on the other hand, are much better for this purpose.

The wipes are great for cleaning and disinfecting the outer casing of the cooler. However, a number of sanitising wipes on the market contain a quaternary ammonium compound as active ingredient and these wipes should not be used on surfaces that subsequently come into contact with the drinking water.  The reason for this is that bio-acclimatisation can occur because of the slight residual effect of these compounds.  This could lead to biofilm growth.

At the end of the day, I would recommend sprays rather than wipes, but if you prefer to use wipes, then make sure that the wipes have a high wet strength and low lint content, otherwise contamination with wipe fragments could occur in the cooler.

Ensure that the wipe does not dry out in the packaging, alcohol-based wipes are notorious for this.  Pouches with a resealable flap are best for preventing dry-out.

Some sprays are based on peroxide, although a new generation of sprays is available which uses a long-lasting disinfectant effect.  The latter is available as a sanitiser (cleaner/disinfectant) as well as a terminal disinfectant. 

How to Disinfect Water Coolers

A useful product available on the market is a disinfectant based on hydrogen peroxide and silver ions. It is recommended for servicing coolers and general disinfection around the bottling plant.

The packaging provides a combination rinse and spray, enabling application by dilution for watercooler disinfection and as a simple spray, by means of the integral and refillable trigger bottle provided. These have proved to be extremely popular, particularly since the price is much less than other alternatives on the market.

It is appropriate to explain the action of silver ions in the formulation. Silver is a well-known biocidal material,  in fact the Romans were aware of this action and stored wine in silver containers to prevent biological deterioration. 

The combination of silver and hydrogen peroxide creates a synergistic disinfectant effect that is more powerful than hydrogen peroxide alone. This, in theory, enables you to use less of the product than hydrogen peroxide alone. 

Among the advantages for the combination are: the more rapid kill rate; the greater effectiveness on algae and fungi; a longer-lasting biocidal action; greater stability in the presence of heat and light and an expected higher efficacy on biofilm.

An additional plus point for the product is the flexible combination pack which enables the trigger spray to be  refilled from the 5 litre container using the convenient tap.

Treating Green Bottles

Green bottles have always been something of a vexed question. Once the filled bottle leaves your plant, you have little control over what happens to it, particularly when it is empty and left for collection.

Bottles left in sunlight and a warm environment are susceptible to algal growth. When green bottles are returned for filling what do you do? On the one hand you can throw them away, but if the algal growth is not too bad perhaps they can be cleaned and returned to the wash/fill cycle.

Green bottles should never be put through the normal washing process, otherwise the bottlewasher quickly becomes contaminated with algae. A separate process is required using good mechanical action, preferably with brushes, and a strong bleaching detergent. Good rinsing is essential.

Simple rigs can be set up to carry out this task and the best detergent to use is a low foam chlorinated alkali at a temperature of about 55 deg C. The temperature must not exceed 60 deg C otherwise the chlorinated product will degrade and cause corrosion, even of stainless steel.

Bottle Washing in Hard Water

Many bottlers wash their bottles in the same spring water that goes into the bottles. I assume that the cost exercise has been done that shows it is more cost effective to do this rather than use mains water.

Using spring water can be a problem if the water contains a lot of calcium, magnesium and some iron. The detergents used in bottle washing have to be specially formulated to take account of the high hardness sometimes encountered and higher concentrations of product are often necessary.

 A saving on detergent can be made if a water softener is used, although the running costs of resin replacement need to be taken into account.

If your water is very hard, it is essential to ensure that the dosage of detergent is adequate and that compensations are made for drag-out during the course of the day. The bottles will “drag out” detergent product as they move into the rinse section. Some washers do not have the luxury of a drain time before passing into the rinse.

The consequences of under-dosing can be catastrophic in very hard water resulting in rapid scale-up of tanks and heaters. It is essential therefore to monitor detergent concentration regularly which may be done easily with a conductivity meter. A more sophisticated system involves automatic top-up using a conductivity probe linked into the dosing device.

                                         Scaled-up heater element

                                           

Reusing Old Water Coolers

The Waste Electrical and Electronic Equipment Directive has been in force for some time. This is intended to ensure that all electrical appliances such as watercoolers and TV monitors are dismantled and recycled at the  end of their useful life, rather than dumped into landfills.

The cost to the watercooler industry is estimated at between £8 million and £10 million. Invoices should show a recycling charge for all coolers bought or rented. This will help monitor compliance and be checked in distributors’ audits.

However, I am sure that we will see refurbishment and reuse of old product rather than just disposal. Innovative solutions will be created for using component parts of old coolers. Whereas the old material may not be reused for water contact in coolers (due to food-contact materials laws) the manufacturer may trade its recycled materials, similar to the trade in waste polycarbonate.

This initiative is to be applauded, but it raises questions of maintaining good hygiene in refurbished coolers. Surfaces which become worn or develop microcracks are more susceptible to growth of biofilm and  more difficult to clean and disinfect. It is essential, therefore, to have a very efficient cleaning and disinfecting regime.

UV or ozonation may not be completely effective in keeping refurbished coolers free of bacteria. It is important to rely on manual operations- for cleaning, descaling, using appropriate acids, and disinfecting with the best material for dealing with biofilm.

Peroxide, or peroxide synergised with silver, is excellent for destroying biofilm. Descaling is done most cost effectively with high-strength phosphoric acid. 

Because the high-strength materials are difficult to handle, I recommend the use of a dosing device which enables dilution and dispensing into the cooler tank without manual mixing or pouring.  

The issue of refurbishment is still under debate but I expect refurbishment schemes will be developed.

Hand Washing in the Bottling Plant

I cannot emphasize enough the importance of correct hand washing. The hand washing area should have a supply of anti-bacterial soap in a clean, hygienic dispenser. Soap should be non-perfumed, low-odour, mild to the skin and taint free.

The temperature and flow of water can have an effect on the success of hand washing. Water should have a decent flow and temperatures between 40-45 deg C. Taps should be knee operated or a hands-free design to avoid contact with taps and sinks.

Drying hands after washing is important because wet hands reduce the effectiveness of the alcohol disinfectant. The preferred method of drying is with good quality paper towels.

The correct method of washing hands is as follows: wet hands before applying liquid soap, rub hands together vigorously for about 10-15 seconds covering both sides of hands, fingers, thumbs, nails and wrists, rinse thoroughly with clean water and dry with a paper towel, apply alcoholic gel to hands and massage all surfaces, allow to air dry.

If gloves are worn, apply alcoholic gel to glove surfaces before work. Wedding rings can be a site for bacterial pockets and rings should always be lifted and turned when washing/disinfecting.

Insects in the Bottling Plant

Bottling plants should be insect free. The most efficient way of doing this is to install an electrocutor. However, careful thought should be given to the design of the equipment and the siting of the device.

When an insect flies into the electrocuter it literally causes the insect to explode. Unfortunately this creates a lot of debris which can easily fly out into the bottling plant. Look out for designs that minimise excessive spatter-back when the insect is killed.

The unit should not be in the vicinity of the filling section otherwise debris may cause contamination during filling. The design of electrocutors has not changed very much over the years but non-electric systems are available. These use glueboard technology and UV lamps. The insect literally sticks to the glueboard without exploding. 

Another aspect is the lifetime of the UV lamps. The power of the UV light is not constant during use and will tail off after several months becoming less effective. This is not noticeable to the human eye. Ensure that the elements are changed at the correct time and service from the supplier is undertaken regularly.

Flavoured Spring Water?

Consumers are being misled by the term “spring water” and further misled by the flavoured spring water drinks, according to a report in “The Food Magazine”. A survey by the Food Commission found that many such drinks use preservatives, colouring, artificial sweeteners and other additives, even though the name on the front implies a relatively pure drink.

Shoppers complained that what they thought was pure water with a drop of fruit flavouring was in fact a sweet soft drink with preservatives and additives, according to the report’s author. The descriptions on the front of the bottles are very misleading.

Tesco’s Spring Water Drink with a hint of grape and blackberry juice for example, or Boot’s Mandarin Still Spring Water with the flavour of mandarin both contain artificial sweeteners, preservatives and acidifiers. Sainsbury’s Crystal Spa made with spring water and natural tangerine flavour has more added sugar than Coca Cola, while Ribena’s Spring has an incredible 13 sugar lumps in a single serving.

Unlike mineral water, which is tightly defined by law, spring water is less rigorously defined and if a flavouring   agent is added then the product is defined as a soft drink, not bottled water, and all the colouring ingredients, preservatives and sweetening agents used in soft drinks can be added.

When Perrier added “a twist of lemon” to their water they started a trend which other companies have been quick to exploit. Shoppers are paying a lot per glassful - these are soft drinks charged at Perrier prices.

Of course, the Australians have gone one stage further and are selling a sparkling “Alcoholic Spring Water” with flavourings and vodka.

"Bisphenol-A Free"?

There has been much debate in the past about the potential dangers of bisphenol-A leaching from polycarbonate bottles.  A lot of research has been done and the European Food Standards Authority has indicated that there is no evidence of any danger from the use of polycarbonate bottles in the bottled water industry.

However, some countries have advised against the use of polycarbonate bottles in baby feeders where high sterilisation temperatures are often used.  As the debate and research go on, new bottles have appeared on the market in 19L, 11L and other smaller refillable bottles with the statement "bisphenol-A free".

To my knowledge, polycarbonate cannot be made without the use of bisphenol-A, so the new bottles are not made from polycarbonate but rather PET with special additives.  The additives are designed, among other things, to improve high temperature stability while maintaining the clarity of the bottle.  This enables high-temperature washing without shrinkage.

However, the chemistry of the additives is fairly complex and more long-term work would be needed to ensure that recyclability is not compromised when re-worked with standard PET or that leaching of undesirable components is no longer an issue.  I am sure that much work has been done already, but it may take some more years' of research before we can dispel completely all fears about unwanted chemicals entering the food chain.

Foam Cleaning

Foam cleaning can be an ideal way of ensuring good hygiene in the bottling plant. The advantages of foam are numerous: increased contact time maximises active ingredients’ effectiveness; the foam is a visual marker for the operator; the expanded foam reduces water and chemical usage; cleaning of large or awkward surfaces is made easier and quicker and therefore downtime for cleaning may be reduced.

Two pieces of equipment are described here which seem ideally suited to the bottling  plant environment. Neither of them requires compressed air and one of them does not need a water line. 

The first is a pump-up foam unit. The dual tube technology draws the chemical and compressed air from the tank into separate tubes creating thick foam when mixed at the trigger foam wand. Flow in the air tube is controlled by a needle valve giving the user the ability to control the consistency of the foam.

The second unit is a spray and foam dispenser which is wall mounted. This enables the operator to generate a cleaning foam, followed by a water rinse and finally a terminal disinfection, all from one piece of equipment.  The only requirement is a water line.

 A single control knob determines water flow and chemical selection, giving accurate dilutions. A built in foam wand hanger prevents foam wand loss or damage.

The ideal foaming chemical is a chlorinated foamer useful for general disinfection and removing mould growth.  An acidic foaming product is ideal for descaling or brightening stainless steel. Recommended disinfectants for spray application are peracetic acid (for water contact surfaces) and quaternary ammonium solutions for floors and walls.

COSHH and Risk Assessments

The COSHH Regulations are designed to prevent people at work being exposed to hazardous substances. The Risk Assessment is a key part of this. The whole process is usually covered by 5 stages: identification; assessment; prevention/control; training and monitoring.

All chemicals must be itemised which are used on the premises along with a list of current work activities. Labels should be checked on containers to determine type of chemical, method of use and precautions. If the  assessment sheet shows there is no likelihood of risk to health from the substance concerned, no further action is required.

A decision is required for each substance and every time the use of the substance, the method of work, its frequency of use, etc is changed, there will be need for a new assessment.

Identification and assessment of the risk will give you an insight into the control and prevention measures necessary to comply with the COSHH Regulations.

The requirement for risk assessments applies not only for chemicals used in the bottling plant, but also for chemicals taken into customers' premises during water cooler servicing.