What is Ozone?

Ozone is simply a gas composed of three oxygen atoms. It is formed when oxygen is exposed to a high-energy field causing some oxygen molecules (O2) to break down to oxygen atoms (O). The oxygen atoms (O) then react with the oxygen molecules (O2) to form ozone (O3). Notice that this is a reversible reaction meaning that ozone can decompose back to oxygen.

Ozone is an extraordinary sanitizing agent that’s economically produced and remarkably effective in applications involving oxidation, sanitation and disinfection. On June 26, 2001, the FDA published a Final Ruling approving ozone as an additive to kill food-borne pathogens. This approval opened the food industry to begin utilizing ozone in their plants and processes to replace conventional sanitation techniques such as halogenated chemicals (i.e. chlorine, iodine, etc.), steam or hot water.

Overview of Ozone Sanitation

Originally discovered in the 19th Century, ozone, a form of activated oxygen generally produced during lighting storms and continuously occurring in the stratosphere due to the action of ultraviolet (UV) rays, is being rediscovered in the 21st century. This naturally occurring compound is now being artificially produced and used in large quantities.

In 1886 ozone was recognized as a disinfectant for water and in 1891 the first pilot plant in Germany proved ozone effective against bacteria. Europe has for over100 years used ozone to treat drinking water and as a sanitation agent. Ozone is one of the earth’s best and strongest natural oxidizers ranking well ahead of chlorinated products.

Chlorine, however, became the chemical treatment of choice after WWI, when the chemical industry found economical methods to produce it. Today, scientists are finding that when chlorine (and other halogen chemicals) reacts with the organic matter dangerous halogenated hydrocarbon by-products such as trihalomethanes (TMH’s ) are produced. When these are found in drinking water they are known as carcinogens and their levels strictly regulated by the EPA.

Historically the United States has established agencies to overview and regulate chemical contact with food and food production; FDA, USDA, FSIS, FFDCA, ARTCA, etc… Definitions were created in which a “food additive” was defined as “any substance, the intended use of which results or may reasonably be expected to result, directly or indirectly, in its becoming a component or otherwise affecting the characteristics of any food”. In 1958 the FDA was required to approve any additive prior to its inclusion in food. There were two exempt groups of substances:

(1) All substances that the FDA or USDA had determined were safe prior to 1958 (i.e. sodium nitrite for lunch meats, etc.).

(2) Generally Recognized-As-Safe (GRAS) substances whose use was accepted as safe before 1958 (i.e. salt, etc.).

In 1982 the FDA declared ozone a GRAS treatment for bottled water. This now allowed US companies to use ozone in its first food application. At that point in time ozone was generated either by UV light or corona discharge. Corona discharge became the choice for most water treatment because it could generate larger amounts of ozone gas. These early generators were normally quite large and the cost to create a pound of ozone was expensive. Ozone, however, continued to be used because of it oxidizing potential (5 times more than oxygen and about twice that of chlorine) and its documented ability of destroy a wide spectrum of microbes (Organisms Killed by Ozone).

In 1997 the FDA was presented with a study that affirms the history and safety of ozone use with foods. The FDA allowed the study to stand as GRAS and in 2000 an “additive” petition was filed by EPRI for the safe use of ozone as an antimicrobial agent for the treatment, storage and processing of foods. On June 21, 2001 FDA publishes it Final Ruling; “the FDA amends the food additive regulations to provide for the safe use of ozone in gaseous and aqueous phase as an antimicrobial agent on food, including meat and poultry.”

Now that ozone has been documented to be a highly affective sanitizer and disinfectant and approved by the regulatory agencies why has it not swept the food industry? The answer to that is simple. There is no institutional knowledge of ozone in any industry. Engineering firms have had little to no formal training in the affects / benefits of ozone. They are well schooled in convention chemical treatments because that’s what has been taught. Since they have no practical experience with ozone most are uncomfortable in recommending something unfamiliar to them. Additionally, chlorinated products and other chemicals are approved and documented so they are professionally correct in recommending their use.

Other variables which have delayed the acceptance of ozone have been the size of the generators, cost to generate ozone gas, ozone generation equipment reliability and the ability to mass transfer large concentrations of the gas into water.

Today, the latter reasons have been overcome. Ozone generator size and cost have fallen significantly as has the cost to generate ozone. Equipment reliability has improved dramatically and the technology to get higher concentrations of ozone in the water is now available. The challenge that remains is the education of the manufactures and the engineering firms on the benefits of ozone to industry, consumers and the environment.


McClain Ozone developed the concept of “Ozone-on-Demand” and it is incorporated into all of our sanitation systems.

“Ozone-on-Demand” is simply the direct delivery of ozonated water from the sanitation system to the point of use. These systems provide on demand ozonation, degassing and delivery of ozonated water to the point of use at variable flow rates.

Although this seems a simple concept, historically ozone systems utilized recirculation tanks to degas and store ozonated water and the water was then taken from the tank to the point of use. This type of system required continually running ozone and recirculation systems, large storage tanks, auxiliary pumps, hard piping installations, constant flow rates and did not lend themselves to mobile point-of –use applications.