More About Ozone

Air Disinfection

Micro-organisms cause issues in various places, in a clinical setting bacteria can cause dangerous outbreaks. Ozone can be used as a chemical disinfectant to kill bacteria and viruses with low ozone concentrations. The contact time is altered depending on the desired deactivation grade as seen in the figure on the left

For many applications a bacteria reduction of 99.99 % which corresponds to a 4 log reduction is sufficient, for a higher deactivation grade the solution is easily adapted to provide higher concentrations and exposure time, in adapted solutions even bacteria spores can be treated. The figure above applies for treatment in rooms and ventilation ducts, we have used ozone to limit the spread of airborne microorganisms in food industries and food storage.

Food Applications

In food applications the migration of microorganism inside the plant speed up moulding, but with gentle ozone treatment the moulding process is easily postponed for several days without damaging the food. Furthermore, in the dairy industry equipment has been sanitised using ozone which performs well and eliminates the need for more harmful chemical disinfectants.

In contrast to the food industry where rooms are often not treated at all, hospitals have high cleanliness requirements and already employs frequent cleaning to reduce the spread of pathogens. This is commonly done by frequent wiping of surfaces with chemical disinfectants.

Although this traditional method is effective, it has been shown that traditional manual cleaning and disinfection practices are often sub-optimal. Reasons for failed cleaning can be due to misunderstandings, deviations from cleaning protocol, not wiping all surfaces, incorrect dilution of cleaning agent either by dilution machine or people and cleaning equipment surface structure being ineffective on certain materials. In a hospital setting such discrepancies increases the risk of pathogen spreading between areas and patients. Automated non-touch technologies are good additions to cleaning practices as it adds another layer of cleaning. (Boyce, 2016)

Non-touch technologies

Non-touch technologies include the usage of UV-lamps and chemicals dispersed as an aerosol or gas which deactivates micro-organisms. Compared to other treatment methods for air disinfection, ozone can efficiently disinfect large air volumes, neutralizing micro-organisms, including viruses. This makes it ideal for use in medical applications, for example in hospitals or doctor's waiting rooms. An important factor that enables savings is the time the cleaning agent can actively deactivate bacteria, as compared in the figure on the left.

The chart shows that the contact times varies greatly. UV cleaning systems often have a very short time window to irradiate the air and therefore needs to add a lot of energy to ensure sufficient deactivation in this short time, wiping with a cleaning solution is limited by the time it takes for the surface to dry while ozone will continue to attack bacteria until it naturally decomposes or is removed.

Ozone Disinfection Benefits

Ozone is produced on spot when needed thus eliminating extra resources required for handling and storing hazardous chemicals. Furthermore, no chemical residue remains after treatment as ozone naturally decomposes to oxygen. In terms of usage, distribution as a gas enables ozone to reach hard to sanitize surfaces, reaching spots difficult to wipe.

Studies has shown that low ozone concentrations are capable of deactivating bacteria and enveloped viruses by reacting with unsaturated fatty acids in the plasma membrane, certain surface proteins and DNA. However, for dealing with stable viruses and bacteria spores higher concentrations of ozone together with air moisture is required over several hours.

In a clinical setting, ozone generators can reduce the risk of pathogens spreading when new patients enters previously occupied rooms.It can also be used after traditional cleaning to reduce the risk of disease spreading from infectious body fluid left by the previous patient.

Depending on customer need the treatment time and ozone concentration is adapted to the desired log reduction. After treatment is finished, ozone either decomposes into oxygen naturally over several hours or the decomposition is accelerated significantly by the use ozone destructers.

For clinics that are closed during the night, ozone treatment can be scheduled in waiting rooms, corridors and bathrooms giving plenty of time for treatment and ozone destruction before the first employee enters.

For surgery rooms or other areas that need a 6 log scale deactivation of bacteria, viruses and even spores, specialised solutions using high concentrations of ozone in a sealed room over several hours is necessary. The sanitation process can be started from a panel outside the room, and information regarding remaining time is displayed. Once the set time is over, the ozone is destroyed with an ozone destructer.

The History of Ozone

Ozone (O3) gas discovered in the mid-nineteenth century is a molecule consisting of three atoms of oxygen in a dynamically unstable structure due to the presence of mesomeric states. Although O3 has dangerous effects, yet researchers believe it has many therapeutic effects. Ozone therapy has been utilized and heavily studied for more than a century. Its effects are proven, consistent, safe and with minimal and preventable side effects. Medical O3 is used to disinfect and treat disease. Mechanism of actions is by inactivation of bacteria, viruses, fungi, yeast and protozoa, stimulation of oxygen metabolism, activation of the immune system. Medication forms in a gaseous state are somewhat unusual, and it is for this reason that special application techniques have had to be developed for the safe use of O3. In local applications as in the treatment of external wounds, its application in the form of a transcutaneous O3 gas bath has established itself as being the most practical and useful method, for example at low (sub-atmospheric) pressure in a closed system guaranteeing no escape of O3 into the surrounding air. Ozonized water, whose use is particularly known in dental medicine, is optimally applied as a spray or compress. Diseases treated are infected wounds, circulatory disorders, geriatric conditions, macular degeneration, viral diseases, rheumatism/arthritis, cancer, SARS and AIDS.

Ozone has been used for over 150 years in many different applications. However it has never been more important to explore its natural ability to disinfect.