Executive Overview of Ozone Sanitation in the Food Industry
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 1891the first pilot plant in Germany proved ozone effective against bacteria. Europe has for over100 years uses ozone to treat drinking water and as a sanitation agent. Ozone is the earths’ best and strongest natural cleanser 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 that chemical. Today, scientists are finding that when chlorine reacts with the organic matter in water dangerous by-products ( such as trilalomethanes - TMH ) are produced. When these are found in drinking water they are known as carcinogens and their levels strictly regulated by the EPA.
The United States 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 (e.g. sodium nitrite for lunch meats); (2) Generally Recognized As Safe (GRAS) substances whose use was accepted as safe before 1958 (e.g. salt).
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 this point in time ozone was generation either by UV light or corona discharge. Corona discharge became the choice for most water treatment because it could generate large amounts of ozone gas. These generators were normally quite large and the cost to create a pound of ozone was expensive. Ozone continued to be used because of it oxidizing potential; 5 times more than oxygen and about twice that of chlorine. Ozone is about 20 to 50 times more reactive than chlorine and permanganates and has a better documented kill rate of micro-organisms. The high kill rates equates to lower retention times for the same level of disinfection as other oxidants. This equated to less capital being spent on plant and equipment.
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 approved and found to be more reactive than chlorinated products 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. Another point that has delayed the acceptance of ozone has been the cost to generate the gas, ozone generation equipment reliability and the ability to infuse large concentrations of the gas into water.
Today, the latter reasons has been overcome. Ozone generation costs have fallen significantly. Equipment reliability is improved with guarantees up to 3 years on corona generators; with some units capable of being mounted on farm spraying equipment. Ozone concentration levels of 14 ppm can be achieved by some manufactures allowing for sanitation times well below chemical treatments. 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.