Measuring Ozone in Occupied Spaces
Some manufacturers or sellers claim that ozone can be used comfortably in any environment. You can see these claims, especially for portable ozone generators. These claims are partially true but can be misleading. To use ozone gas in occupied spaces, ozone should be measured continuously and the ozone gas should not exceed the values determined by the health & safety organizations in the world. Most importantly the ozone safety monitors should command the ozone generator.
Ozone concentrations within an occupied space can vary greatly at various points, and concentrations are often highest in unexpected places.
Key points measuring ozone
- Ozone is much heavier than air, it sinks to lower levels.
- Because ozone has a low vapour pressure, it does not attempt to fill the room uniformly. It tends to remain stationary.
- Ozone tends to cling to rough surfaces such as fabrics and breaks down (converts back to oxygen)
- Ozone reverts to oxygen with a “half-life” (the time it takes to reach half of its original concentration) of 10-30 minutes.
- Strong “reducing” gases, such as vapours of alcohol and solvents, can reduce the apparent concentration of ozone.
- Ozone has a distinctive smell, but the odour threshold varies widely by person and by ambient conditions. Therefore “smell” is not a reliable test for the presence or concentration of ozone.
What matters is the ozone concentration at the breathing level where the room occupants will be.
The alternate point of measurement for ozone introduced by HVAC systems with good room air circulation is near the entrance to the return air duct.
This post is cited from Ozone Solutions