How Ozone Disinfection Works

Ozone occurs quite readily in nature, most often as a result of lightning strikes that occur during thunderstorms. In fact the “fresh, clean, spring rain” smell that we notice after a storm most often results from nature’s creation of ozone. However, we are probably most familiar with ozone from reading about the “ozone layer” that circles the planet above the earth’s atmosphere. Here ozone is created by the sun’s ultra-violet rays. This serves to protect us from the ultra-violet radiation.

Ozone, (O3), sometimes called “activated oxygen”, contains three atoms of oxygen rather than the two atoms we normally breathe. Ozone is the second most powerful disinfectant in the world and can be used to destroy bacteria, viruses and odours.

Ozone is currently used in a wide range of applications including, pools, fruit and vegetable cleaning, room deodorising, sewerage treatment and as a disinfecting process for bottled water just to name a few.

Ozone is created when air is exposed to either: ultraviolet light, lightening or high voltage electric arcs.

EnviroSaver uses the ozone manufacturing technique known as a ‘corona discharge’ – by sending a spark through a stream of oxygen.

The electricity produces arcs that come into contact with the oxygen (O2) that splits oxygen molecules into single oxygen atoms.

The separate atoms then attach themselves to other oxygen molecules (O2) thus creating ozone (O3).

Ozone very quickly reverts back to oxygen after it is used. This makes it a very environmentally friendly oxidant.

Compared to UV ozone systems, corona discharge systems create much more ozone at a higher concentration by weight, making them better suited for commercial and high-volume applications such as laundry disinfection systems.

When used in a laundry application ozone disinfects the wash water and everything in the wash water. Because this is achieved in cold water, it results in dramatic utility cost savings. It is for this reason that the application of ozone in laundry has gained rapid international acceptance over conventional laundry methods which require substantial amounts of hot water.

The third oxygen atom of ozone makes it extremely reactive. This makes it the second most powerful disinfectant in the world. Ozone attacks most organic soils and kills bacteria 3200 times faster than chlorine bleach.

Yes it does.

The Australian Standard AS4146-2000 details two methods of disinfection in laundry; they are Thermal Disinfection (Section 3.5.2) and Chemical Disinfection (Section 3.5.3).

Thermal disinfection requires that the main wash is heated and maintained to either 71c for 3 minutes or 65c for 10 minutes.

Chemical disinfection requires a process of applying chemicals that increase the oxidative qualities of the wash bath that are then validated by swab tests conducted by the chemical supplier. The swab test is an aerobic bacterial plate count of less than 1 microorganism per square centimeter.

As mentioned earlier in this document we use a measurement of “ORP” to ensure that the disinfection process is set up correctly. EnviroSaver also has a failsafe system in place that will not allow the wash process to continue unless all of the factors reliant on ORP are achieved, i.e. ozone generation and delivery.

There have never been any reported long-term affects of exposure to ozone, however just like many disinfectants, ozone can be harmful if it were ever ingested in large volumes. Fortunately, this is not possible with the way ozone is blended with the water.

Ozone is diffused directly into a closed loop of water which means that there is no opportunity for ozone to escape into the laundry room.

The World Health Organisation requires that no working environment have ozone levels exceeding 0.1 ppm over an eight hour period or 0.3 ppm over a 15 minute period.

Our system does not release enough ozone into the environment to exceed these levels in fact a wall mounted air conditioner produces higher amounts of residual ozone in a laundry room than the ozone system itself.