Ozone Re-Emerges as an Economical and Green Safety Tool

In 2000, the Electric Power Research Institute published “Food Industry 2000: Food Processing Opportunities, Challenges, New Technology Applications.” The report contains the following statement: “Ozone destroys bacteria, mold, mildew, spores, yeast and fungus. It inactivates viruses and cysts. Chlorine is not very effective against viruses and has limited effect on some types of bacteria … ozone reacts much faster than chlorine.”

Ozone is a cleaning and a sanitizing agent. Ozone-based systems have been marketed to the food industry for some years but have not gained wide acceptance until recently. The reasons for this lag include inadequate science, ineffective validations, lack of service after purchase, and general skepticism about new technology.

So what has changed? The main thing is the sudden realization that ozone systems can keep a plant clean and sanitized throughout the production day for less money than current modalities. The recent rash of food safety warnings and the resultant recalls have brought financial disaster to affected companies. Ozone systems now operate in many food industries, including seafood, poultry, produce, beef, pork, prepared foods, and water bottling.

Food processors are, by necessity, taking a second look at the new generation of ozone systems and their unequaled ability to maintain plant cleanliness and sanitation throughout a production day. The capacity of ozone as an effective degreaser and sanitizer on conveyor belts during production greatly reduces the risk of cross contamination. Ozone sprays are used continuously on direct food surfaces such as conveyors, knives, slicers, and portioners, assuring their cleanliness throughout production.

Recently, processors have even begun interventional ozone cleaning of indirect surfaces at breaks and shift changes. Ozone’s use during production yields a cleaner plant and decreases the labor time needed for full plant sanitation. Ancillary benefits include reduced energy costs resulting from a large reduction in hot water consumption and chemical cost reductions resulting from lessened chemical usage. Return on investment for direct costs can typically be realized in six to 10 months.

Industry Mea Culpa

The past failures of ozone can largely be traced to the ozone industry itself. The fact that ozone is stronger and acts more quickly than equivalent concentrations of chlorine, coupled with its many cost-saving advantages, seemed to guarantee its rapid adoption. Numerous mom-and-pop operations sprang up, touting ozone as the next generation of sanitizing technology.

Unfortunately, because of ozone’s instability, it cannot be pressurized or heated, which made early ozone systems ineffective. The small companies lacked the funds to keep up with the needed science and to develop the sophisticated systems essential to manufacturing a reliable product for commercialization. Mixing technologies were crude, leading to “off-gassing” problems that raised worker health issues.

Ozone companies knew how to make ozone but knew nothing about the industries they were trying to supply. They didn’t have the funds to develop a competent application engineering capability. Too often, a company would ship an ozone system to a customer, claiming the system could sanitize. The customer was left to implement the system, usually a recipe for disaster. More recently, however, the emergence of several better-funded companies has allowed the industry to address its shortcomings and begin to realize its potential.

Ozone 101

Ozone is usually dissolved in water and applied as an aqueous solution. Ozone application to direct contact surfaces is begun prior to the start of production and is continued all during production, keeping surfaces clean and sanitary through the day. It is easier—and obviously more desirable—to keep belts and equipment clean during production than it is to clean them after they are heavily soiled. Ozone systems are also used to augment current cleaning practices, providing the additional sanitation benefits of continuous cleaning.