Ozone treatment maximises bug kill in high risk food production areas

As the use of aggressive sanitising chemicals -- particularly those based on chlorine -- is progressively restricted in Europe, food processors are urgently in need of effective alternatives.

In response, Steritrox has developed a sanitising system that doesn't rely on harmful and expensive chemicals but still delivers maximum killing power. It uses ozone-based technology to sanitise any food processing plant in a fast, safe and controlled process.

Hygiene managers in food plants are constantly battling to prevent a wide range of potentially harmful micro-organisms from contaminating products. A variety of chemicals have been traditionally used to systematically disinfect all aspects of the manufacturing environment from walls, floors, surfaces and equipment right through to the product itself.

One of the biggest issues currently facing the industry is that most high care areas continue to rely on a range of chemicals, including various forms of chlorine, such as chlorine dioxide and sodium hypochlorite.

Also used are branded forms of quaternary ammonium compounds and even bromine or iodine-based products. The long-term use of some of these products is now coming under close scrutiny from environmentalists, claims Steritrox md Peter Townley.

Misunderstanding

Advanced oxidation has for many years consistently demonstrated the killing power needed to meet the industry's strict standards, but it has in the past been largely misunderstood and poorly implemented, claims Townley.

Modern process techniques, however, have now made it possible to turn molecular oxygen into highly reactive ozone, which in turn reacts with humidity to produce naturally occurring compounds including hydroperoxides, super oxide ions and hydroxyl free radicals, says Townley.

These controllable compounds are all highly effective antimicrobial and biocidal agents, and will also efficiently destroy even extreme odours, ultimately breaking down naturally to leave no detectable residues.

The problem in the past has always been managing the ozone system to deliver a controlled killing action that is compliant with the stringent operational environment that is essential in a modern food production factory.

However, Steritrox has developed a sanitising system that addresses these issues, providing the enhanced microbial killing power associated with advanced oxidation without the need for extended production down-time previously experienced with ozone-based fogging systems or the harmful side-effects of the aggressive chemical systems.

The process actively controls the production of an ozone-based vapour that quickly permeates all elements within the production area with a biocidal atmosphere. Sanitisation is automatically managed under computer control and transforms naturally occurring elements contained in the air into a highly reactive vapour which is rich in free radicals.

Once the sanitising programme is started and the operator leaves the room, the Steritrox vapour diffuses into every corner of the room, bathing all exposed surfaces and penetrating hidden areas and fabrics such as drains and air conditioning vents.

The atmosphere is sustained for a short period of time, typically less than one hour, during which time all bacteria are said to be destroyed. The vapour in the atmosphere is then neutralised using a quenching agent. This produces a further burst of free radicals, which not only increases the killing potential but also uses up all the remaining Steritrox vapour.

SAFE to use

This removal of any residual vapours makes it safe to enter the room within a few minutes of the process finishing. The only residuals are water and fresh air.

The new system is said to give the operator complete control over the sanitising process and in most cases means the whole procedure takes less than an hour from start to finish.

Initial testing at both Campden and Chorleywood Food Research Association and Manchester University over a range of eight major organisms (Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, Bacillus cereus, Staphylococcus epidermidis, Listeria monocytogenes, and Enterococcus faecalis) has been supported by field trials to prove the system to be extremely effective, efficient and robust, says Townley.

One major food processing company recently started using the Steritrox process to sanitise its high care food preparation unit in the Midlands. In a production area some 1,800m3in size full of production equipment the process completed its sanitising cycle within an hour and consistently achieved the desired kill rate.

Within five days of initial application of the process the background micro-count had dramatically improved as the vapour permeated into previously hard-to-get-to places. Three instances of Listeria were found on the first three nights of treatment. All were eradicated on each occurrence and significantly the infection did not reoccur on days four and five.

The Steritrox process is now being used by several food processing companies in the UK as part of their sanitising procedures.

Contact: Steritrox, Tel: 0161 430 8721​