The International Ozone Association (IOA) was formed in 1973 to serve as the central vehicle and authority for the global gathering, dissemination and transfer of ozone technology knowledge. The IOA brings together the world’s leading ozone scientists, engineers, systems designers, technologists, ozone equipment manufacturers as well as the leading end users to share their experiences and research data. In partnership with Water Quality Products, the IOA O3 Zone monthly column will educate readers about this exciting and rapidly growing technology.
Any conversation about the status of the bottled water industry around the world will eventually touch on ozone. Both in terms of the future of bottled water and the physical end of the bottling process, ozone is the endgame. With a single application of ozone gas, a bottler can disinfect the water stream, the bottling machine’s water contact surfaces, the bottle and sealed cap, and sometimes, even the air contained in the bottle. Furthermore, this single ozone treatment can be engineered to provide high-quality disinfection residual to ensure a product with the greatest quality and longest shelf-life.
Ozone, a triatomic allotrope of oxygen, is the world’s most powerful commercially available oxidant. Widely known as the reactive barrier that regulates the earth’s temperature and sometimes misunderstood as a byproduct in urban pollution (Ozone is more of a temporary byproduct than a pollutant.), ozone actually has a well-documented history of scientific and industrial applications due in large part to the efforts of the IOA, the information clearinghouse and auth-ority on ozone technology since 1973.
It has been shown that ozone treatment combined with filtration can remove undesirable substances without any major alteration of the water’s chemical composition, which is important for meeting U.S. FDA regulations and consumers’ expectations.
Based on the shared development and end-use, the history of ozone in bottled water is grounded in the history of ozone use for municipal water treatment. Additionally, many bottlers who don’t rely on groundwater or surface water draw their water from U.S. EPA-regulated municipal water sources and then perform some finishing processes to handle chlorine odor and taste—a continuation of the existing process.
Ozone’s first industrial application was for municipal water treatment in Nice, France, in 1906. Across the Atlantic in the U.S., rapidly expanding cities along with burgeoning agriculture and industrial sectors provided ample demand for usable water, and ozone was quickly adopted as an interesting alternative to chlorine treatment.
According to Rip Rice, a founding member of the IOA, “The first cont-inuous process for the disinfection of drinking water in the U.S. may well have been ozonation.”
Indeed, military scientists at Fort Niagara were searching for an effective water treatment method and experimented with ozone disinfection in 1909. Though their results and pro-gress were positive, the technology at the time was not well suited for mobile military units. The shortage of reliable ozone technology and the funds to invest in it slowed the use of ozone. Robert Bunsen, pioneer of spectro-scopy, predicted: “When ozone can be produced commercially hundreds of uses will be found for it.”
This proved true as ozone was implemented not only in drinking water but also for the oxidation of industrial process chemicals beginning in the 1940s, and odor oxidation became an established market in the 1960s. As it was implemented more broadly, ozone’s other uses, such as coagulation and color removal, were also utilized. Today, ozone is used in industries such as industrial water treatment, pharmaceuticals, fish hatcheries, swimming pools, electronics, and the bottled water industry—in which 95% of U.S. bottlers use ozone for disinfection. Around the world, the market for ozone technology is projected to grow more than 6% per year through 2009.
Ozone, and certainly its technological advancement, was a key factor in the development of the bottled water industry, which averaged double-digit growth rates in the U.S. over the last 16 years, and is the fastest-growing product in the beverage industry. Ozone is crucial in bottled water for improved taste, elimination of odor, improved clarity, and increased storage life—and ozone also completely eliminates the need for chlorine and its harmful byproducts.
In the 1970s, as bottled water consumption grew around the world, the bottling technology and process were not as consistent as they are today. Sometimes, bottles were improperly sealed, so in the handling of the bottle, airborne micro-organisms could enter and reproduce in the bottle. After time on the shelf, microorganism growth could compromise the purity and health of the water, sometimes creating a slime ring at the air-water interface in the bottle.
Bottled water wasn’t always disinfected effectively, and this growing industry was faced with significant scrutiny by the media and public due to bottled water recalls. Ozone technology, propounded and supported by the IOA in those early days of bottling, was able to take water bottling to the next level, which allowed the industry to grow markedly and become an everyday consumer beverage product.
“One might say that the newly developed ozone treatment saved the bottled water industry in the early days,” said L. Joseph Bollyky, Ph.D., former president of the IOA.
In addition, the increased environmental awareness of the 1960s and 1970s brought about more stringent environmental regulations. In 1986, the Safe Drinking Water Act was amended to include testing standards for Giardia, enteric viruses and Legionella. It established a concentration x time (CT) value to achieve required disinfection levels for EPA-accepted oxidizing biocides. Ozone’s CT value is lower than the other EPA-specified disinfectants because of its rapid and powerful oxidation. Ozone’s all-purpose disinfection hits every stage of the bottling process, and its comprehensive reactivity assures a safe and sequential decomposition back into regular oxygen, providing a clean, fresh taste in the final product.
In 1982, the U.S. FDA declared ozone to be “generally recognized as safe” (GRAS) for food contact, and therefore, also in bottled water. The FDA has established ozone treatment as a Good Manufacturing Practice (GMP) for bottled water.
The FDA adopts the relevant drinking water requirements set by the EPA, and in turn, the International Bottled Water Association (IBWA), which represents 85% of bottlers in the U.S., sets its regulations based on those of the EPA and FDA and specifies ozone application as a treatment practice.
In March of 1997, the EPA recognized the contribution and value of the IOA, with its wealth of experience in ozone application technology and compendium of scientific studies. The IOA became a participant and stakeholder in the REG-NEG process, the development of EPA regulations.
One issue in the application of ozone for bottled water is the incidence of bromine in groundwater. While naturally occurring minerals add a characteristic taste to some bottled waters, oxidation of these elements can lead to complicated byproducts. Bromate (BrO3-) is an important consideration for ozonation of waters containing more than 0.10 mg Br-/L. When high levels of bromide are present, overzealous ozone treatment can lead to a bromate level higher than the 10 µg BrO3- maximum contaminant level (MCL) established by the EPA. Steps can be taken, however, to minimize bromate production. By dosing ozone accurately with properly designed bottling systems, the treatment process (CT) value will disinfect the water effectively while mitigating bromate production. Furthermore, studies have shown that lowering the pH of the water from 7.6 to 6.8 results in almost 60% reduction in bromate to under the MCL while maintaining the high-quality taste expected.
As obstacles to effective disinfection arise, practical analysis and technology are able to employ ozone’s dynamic and flexible reactivity to find an even better solution.
Ozone’s dynamic nature made it a challenging molecule to utilize until reliable and affordable equipment was developed. Then, later in the 20th century, an acceleration and expansion of applications began, and today, ozone is an integral part of commercial and industrial applications through the professional and scientific efforts of organizations like the IOA, IBWA and American Water Works Association, among others. The IOA (www.io3a.org) has been instrumental in facilitating and sharing the scientific discourse necessary to harness technology that effectively applies ozone in diverse and specific applications.
As bottled water continues to grow in developing markets all around the world, ozone will continue to enable both small bottlers and large corporations such as Coca-Cola to scale their operations and adopt new technologies while producing high-quality, easily storable product.