Ozone Destruct Unit Information

Posted by Ozone Solutions on 18th Oct 2021

Why Use an Ozone Destruct Unit?

The use of an ozone destruct unit is an essential safety measure when dealing with high concentrations of ozone. Many applications do not require destruct units, such as our  FridgeZonePurizon, and Enozo products. When the need of high ozone concentrations arise, such as a nasty case of mold or severe odor problems, a shock treatment is applied. This means that a large amount of ozone must be used to eliminate the source of the issue. At shock treatment levels, ozone becomes toxic; it can be very harmful to people, pets and other living organisms. An ozone destruct unit will safely destroy any excess ozone that is present in the ambient air or ozone that is off gassed from a contact tank.

While all Ozone Destruct Units are designed to perform the same task, (destroying ozone) there are differences in these devices that will affect the performance of each within the specific application.
There are a few factors to consider that will narrow your search quickly:

  • Will you require a high concentration ozone destruct unit or an ambient air ozone destruct unit?
  • Will the air stream be a wet air stream or a dry air stream?
  • What is the initial ozone concentration and what is the desired effluent ozone concentration?

What is a High Concentration Ozone Destruct Unit?

Ozone Destruct Unit

The term high concentration refers to any ozone concentration above the immediately dangerous to life or health(5 ppm). Usually this means the excess ozone is a by-product of an ozone process.
A few examples of this may be:

  • Ozone off-gassed from a contact tank
  • Ozone within a disinfection chamber
  • Ozone in a vent hood

At Ozone Solutions, we designate our high concentration ozone destruct units with the prefix ODS. Our ODS ozone destruct units will operate with ozone concentrations up to 20% by weight. The ODS units are passive devices meaning there is no integrated device to move air through the unit, air flow must be provided by the customer's application. These destruct units are sized on air flow in CFM. For example, the ODS-3 is a high concentration ozone destruct unit that is rated for 3 CFM of air flow.

What is an Ambient Air Ozone Destruct Unit?


Ambient air ozone destruct units operate within environments much as the name implies, in the ambient air. These devices are used to remove ozone within occupied space or space where ozone levels need to be lowered for a process. A typical application may be within a laboratory chamber where ozone will negatively affect a test or process.
A few other applications may be the following:

  • Micro-array test chamber
  • Small occupied space with ozone levels above the OSHA levels
  • Disaster remediation pack-out rooms

At Ozone Solutions we designate our ambient air ozone destruct units with the prefix NT. Our NT ozone destruct units have integrated fans to move air through the destruct unit. These units are sized on air flow in CFM. For example, the NT-70 is an ambient air ozone destruct unit that moves 70 CFM of air.

What is a Wet Air Stream?

A wet air stream is any air stream from a water application. This usually means an ozone contact tank or water storage tank. This air will be moisture laden and have a high humidity level. The catalyst material inside the ozone destruct unit will be destroyed by condensation. To destroy ozone in a wet air stream, the ozone destruct unit must be manufactured to prevent moisture from 


condensing on the catalyst. Also, a wet air stream must pass through the ozone destruct unit at 1/2 the flow rate of dry air to achieve the same efficiency. Ozone destruct units designed to operate in a wet air stream must be larger and hold more catalyst to work efficiently.

ODS-H destruct units are manufactured with a heater to warm the air and catalyst inside the ozone destruct unit. Also, they feature an air gap that will equalize the air flow and speed. There is also piping used in the ODS-H series to ensure the air is properly warmed prior to contacting the catalyst and for the potential of condensed moisture to drop via gravity back into the incoming tubing.

At Ozone Solutions, we designate ozone destruct units designed for wet air streams with the H suffix. For example, the ODS-3H would be suitable for a wet air stream, while the ODS-3 would only be suitable for a dry air stream.

What is a Dry Air Stream?

A dry air stream is any air stream without condensation. Normal ambient humidity levels up to 85% should be considered a dry air stream. Any of Ozone Solutions ozone destruct units will be suitable for a dry air stream.

How do I Determine the Effluent Ozone Concentration?

This is an important but commonly overlooked factor when choosing the right ozone destruct unit. At Ozone Solutions all of our ozone destruct units are sized and rated air flow in CFM. There is also an efficiency rating for each ozone destruct unit. Either 99.96% for the ODS series or 99% efficiency for the NT series. This efficiency rating is at the maximum air flow for each device. For example, the NT-70 will destroy 99% of the ozone gas in a 70 CFM air stream.

Here are a few more examples:

  • NT-70 operating at 70 CFM and 5 ppm ozone concentration will result in a . 1% of 5 ppm = 0.05 ppm
  • ODS-3 operating at 3 CFM and 10% ozone concentration will result in a 0.004% ozone concentration. 0.04% of 10% ozone = 0.004% ozone = 24.2 ppm. A flow rate of 3 CFM at 24.2 ppm ozone is still well above the OSHA level of safety and a potentially dangerous situation.
  • ODS-3 operating at 1 CFM and 5% ozone concentration will result in a very low ozone concentration. At 1 CFM the ozone level is lowered by 99.96% three times. 5% ozone concentration reduced by 99.96% three times will result in a value of ozone well below detectable limits.

What Happens to the Ozone?

The ozone (O3) is catalyzed back into oxygen (O2) through a catalytic process using the ozone destruct catalyst. This is completely a catalytic reaction requiring no consumables.


What is the Catalyst Material?

The catalyst used inside all of the ODS units is a proprietary granular media. The NT series of ozone destruct units use a proprietary honeycomb material to destroy ozone. If you would like MSDS information for the catalyst material, please call us at 712.439.6880.

Does the Catalyst need to be replaced?

While the ozone destruction process is a catalytic reaction the catalyst will still become unusable after time. Moisture, dust, VOC's and other contaminates in the air will eventually either poison, contaminate or break down the catalyst inside the destruct unit. We recommend replacing the catalyst inside your ODS series ozone destruct units every two (2) years. Replacement catalyst can be purchased here.