Electrolysed Water, Sustainable Sanitisation for the 21st Century?

Background

To find a product that is effective at reducing bacteria and viruses, is safe for use in public areas and with foodstuffs, has a short contact time and is also low on cost, is the ambition of every infection control professional.

The chemical industry has reformulated and repackaged its ever increasing product ranges over the last 50 years in its attempts to satisfy the constantly changing demands of infection control practitioners. However, behind the shiny new packaging and marketing campaigns, there is really very little in terms of true, chemical development.

In the 1960s, Russian scientists commenced development of a commercial application for water electrolysis. There was clear evidence that this technology could offer something that, up till then, had not been available. Early testing showed it to be a very effective and, potentially, low cost means of killing bacteria. Unfortunately, however, the technology proved difficult to harness, especially on a scale necessary to realise its cost efficiency.

30 years later several Japanese companies reassessed the technology and, using their nation’s aptitude for electronics, succeeded where the Russians had failed. One of the most prominent companies involved was the Hoshizaki Electric Company, which quickly began producing cost effective production units with minimal footprints under the brand name ROX, derived from (Reduction OXidation).

With the backing of Hoshizaki’s world renowned reliability alongside its sheer production flexibility and cost efficiency, ROX sold in its thousands across the food production and health care industries throughout Japan.

ROX is now available in Europe and specialist distributor, EOwater, is driving the market development in the UK for Hoshizaki.

What ROX Produces

Water electrolysing, of course, is not in itself new but an easy and reliable method of harnessing it on demand has never been available before. ROX’s technology starts by cleaning tap drawn water and adding salt to produce a saline solution. This solution is then electrolysed, causing it to change to two new products, one an alkaline, the other an acid.

The alkaline is a 1% solution of sodium hydroxide while the acid is a 0.1% solution of hypochlorous acid. The alkaline is a useful cleaning solution, however the acidic water is a potent sanitiser.

Hypochlorous acid is, essentially, an unstable element of chlorine, which means that it quickly reverts to its original state. Quite simply, although it is extremely powerful when released, at which time a light smell of chlorine is apparent, within a few seconds it disappears, as the hypochlorous acid dissipates.

Drawn on Demand

For a commercial chemical manufacturer, producing hypochlorous acid is not financially viable as its extremely short shelf life makes it highly impractical to store. Therefore, hypochlorous acid is not readily available to purchase.

The Hoshizaki ROX, however, enables hypochlorous acid to be made on site and on demand.

Because the hypochlorous acid is only drawn off as required, there is no wastage. At the time it is drawn off, its efficacy is at its most potent level, so there is no compromise on quality. The customer also has the option to store it in opaque spray bottles where it will remain useful for a minimum of 7 days.

Once used, the product can be safely discharged to the main drain without effect.

Bespoke Systems

EOwater designs the optimum system for every site with as many user access points as required. ROX systems range from simple over-the-sink production units to systems with over 600 litres of storage and the capability to produce over 4,000 litres of both acidic and alkaline water per day. Numerous units can be combined for unlimited production and unlimited storage. In Japan, where many systems are in use, it is common to find a small, single outlet ROX unit in a café or restaurant and complex configurations serving major food production units.

Safety

The acidic water is designed to be used as part of a hand wash system and, in Japan and US, is approved as a “Food Additive”. This clearly indicates that it is a low hazard product that is safe to use and to come into contact with skin. It is not even harmful if accidentally ingested. (Reports available)

Because it is completely safe, it can be used in public areas without risk – even when human contact is likely.

Use

The process of killing bacteria is usually achieved within seconds, with common bacteria such as MRSA dying in just 5 seconds. Because of its unstable nature, the chlorine dissipates almost instantly, leaving no residue. In the case of hand washing, within seconds of drying hands there is no smell of chlorine. When used for washing food, the flavour is completely untainted while when used. The speed of the process prevents bacteria and viruses from developing immunity so, using ROX in place of standard chemicals, means that it will always be effective and also eliminates the need for brand alternating.

Cost

When a ROX system is installed there is no financial advantage to the supplier whether the customer produces large or small volumes of product. Unlike traditional chemical cleaners and sanitisers, where increased demand means larger orders, there is virtually no more revenue generated from greater use of ROX equipment. In fact, when all costs are considered as a capital project, to include finance, water, electricity and salt, the average cost per litre for a standard installation is only 2p.

Research papers

As part of its commitment to research and development, Hoshizaki has supplied ROX equipment to various universities around the world to encourage independent research. This has resulted in much published scientific evidence to prove that it does work as stated. Essentially, all the research concludes that acidic water kills a wide range of bacteria and viruses, is safe to use, and leaves no residue. It has been shown to have beneficial effects when used to clean fruit and vegetables in that it extends its shelf life, has no adverse effect on the quality of the foods it is used to wash and brings big benefits to fish and shell fish that are to be eaten raw.

The research papers also raise a further issue – why is it so effective so quickly? It is agreed by all that bacteria and viruses are killed by ROX water and that there are three main components of the effectiveness, chlorine content (around 80ppm) ORP (more than 1200mv) and pH (around 2.8). However, from a vast array of studies covering applications across food production, food processing and food consumption, farming and horticulture, health care and nursing homes, the researchers cannot agree on why it is so effective – but unanimously agree that it is.

References

Kim et al: Role of ORP in Electrolyzed Oxidizing and Chemically Modified Water for the Inactivation of Food-Related  Pathogens:  “ORP should be considered as the primary indication of disinfection (or oxidation) capability.”

Fabrizio et al: Comparison of Electrolyzed Oxidizing Water with Various Antimicrobial Interventions to Reduce Salmonella Species on Poultry:  “Many studies have described the use of both pH extremes being used to inhibit of destroy foodborne pathogens.”

Koseki et al: Decontamination of Lettuce using Acidic Electrolyzed Water:  “We had concluded the main factor of antimicrobial activity of AcEW was available Chlorine.”