How Long to Wait After Using an Ozone Generator

Based on the marketing information from companies that produce ozone generators, they’re effective against unpleasant indoor odors. As a result, many people have invested in ozone generators for their homes to combat occasional or frequent bad smells.

The most common indoor odors people say they would like to get rid of are cigarette smoke, the smell of our pets, the smell of old furniture, or sometimes even our own, human odors.

Although ozone generators are not the most widely accepted air purifying technology you can find, many people still use them and claim their efficiency against unpleasant indoor odors.

Ozone generators are commonly used for both residential and workspaces, however, you need to know how to use them correctly, as ozone poses a certain level of health risk, which is why we need to be careful with it.

One of the most common questions we get from our readers is ‘how long to wait after using an ozone generator’? And it’s a good one because prolonged exposure to ozone, especially if we’re talking about generated levels of ozone, can be very harmful to one’s health.

In this article, we are going to talk about how long you need to wait to use a room again after using an ozone generator, how long ozone lasts in the air, as well as what are the best ways to use it in your home.

Ozone Generator – What Is It and How Does It Work?

An ozone generator, also known as ‘Ozonator’ belongs to the category of air-cleaning devices, despite the fact that its power and efficiency have been disputed many times.

Exposure to ground-level ozone is considered to be dangerous for human health, especially for the respiratory system. However, it has shown to be somewhat effective with removing the volatile organic compounds, or simply put – odors, from the indoor air.

Basically, these have shown useful in cases when neither charcoal, baking soda, nor regular air purifiers are being sufficient to remove the unpleasant smells.

The Ozonozator works in a way that it’s trapping the air full of carbon dioxide, binding to it, and transforming it to ozone. This type of electrical discharge is also known as ‘corona discharge’, and the underlying process involves splitting the carbon dioxide molecules in order to create a free-floating oxygen molecule to which other oxygen molecules can join to create ozone.

Another way for an ozone generator to work is via ultraviolet radiation where the machine is imitating the way the Sun’s UV rays are splitting the atoms of oxygen, however, this method is considered less effective compared to corona discharge.

For those who would like to know more, the ozone molecule has three atoms (unlike the oxygen molecule which contains two atoms). Ozone molecules have the ability to detach from their main structure easily and become a free-floating oxygen molecule which then can bind to other chemical structures be it germs, viruses, bacteria, or volatile organic compounds. Once this happens, the molecule to which ozone has attached alters.

When you decide to use the ozone generator to fix the air quality in your indoor space, make sure to keep all of the doors and windows closed, and leave the ozone generator running for some time. Also, make sure that no one is in the room while the ozonization is being performed.

Once the job is done, you should open doors and windows and let the ozonized air out. It’s not recommended to breathe ozone-enriched air.

How Long Should I Run an Ozonozator in a Room?

How long an Ozonozator should be left working in a room depends primarily on the room size, but also on the amount of ozone the machine is producing. A general rule is that the unit shouldn’t work for less than 3 hours and also no longer than 10.

If you want to ozonize your entire house, you will probably need one whole day (24 hours) of continuous operation.

How Long Does Ozone Take to Dissipate?

Usually, it takes between half an hour and several hours (but no more than 5) for a single atom from ozone to split and become free-floating oxygen. Then, ozone itself needs some half an hour to 2 hours to become breathable in case of lower concentrations of ozone in the air, but in case of higher concentrations, it can take up to 4 hours.

This means that you should wait at least four hours after the ozone generator has done its job before you go into the room.

It would be for the best, however, if you could wait even longer, perhaps even the whole day, as that you’re making sure that you’ll end up breathing no ozone in your indoor air.

The speed at which ozone disperses depends on the size of the room, the indoor temperature, the amount of dust present, and indoor pollutants.

Usually, it’s difficult to estimate the situation precisely, which is why we recommend waiting a longer period – more than 4 hours after your ozone generator has finished working.

How to Know Whether You’re Having an Ozone Leak?

Just to be safe, you should be informed on how to detect an ozone leak as this can be quite dangerous in case it happens.

The two most common ways of detecting ozone are Draeger tubes, which you can use to detect many different gases, ozone being one of them. People are usually sensitive to ozone levels that range between 0.01 and 0.03 ppm. Draeger tubes contain certain chemicals that are able to detect the presence of ozone, so you can use them to detect whether there is any residual ozone in your indoor air.

Another method is to use an air quality meter or an ozone detector that you can put on a wall. The device usually has an ozone-sensitive sensor that can detect the presence of ozone in just a few minutes, and it will usually give you the results on a digital display.

How to Learn About How Long to Wait After Using an Ozone Generator Like a Pro

Before we wrap up, let’s see what are the steps you can take to be fully informed on how long to wait before you return to the indoor area after using an ozone generator.

Read the Manual

If you plan on using an ozone generator, make sure to read the manual on how it works. This can help you prevent ozone pollution in your indoor space. When you are using the ozone generator in a single room, you should close all doors, windows, and vents, so that the ozone doesn’t leave the room and spread around the other rooms and hallways. If you plan to use the ozone generator to freshen up the whole house, you should make sure that everyone is out of the house.

Define How Long You Will Run the Unit

If you’re running an ozone generator, on average it should be some 3-6 hours. But this can change in case you want to ozonize more than one room or the entire house.

Use the Timer on the Generator

Usually, ozone generators have built-in timers that run for between 20 minutes and 10 hours. Once the timer runs out, it will switch off. This means that even if you are away, you can rely on your Ozonozator to switch off without your presence, and then all that is left is to wait for those additional hours before you return to your ozonized room. If you are returning earlier to ventilate the space, and you need to enter the ozone zone, make sure to wear an N95 face mask, as you don’t want to breathe in the ozone. This also stands in case your unit has no timer or the timer is broken for some reason. Once you’re done opening the windows or switching off your unit, exit the room as fast as possible.

Wait Before Going Back In

Since entering an ozone-full room is hazardous for your health, make sure to wait long enough before entering. As mentioned before, 4 hours is a minimum of wait, but you can add some hours to that.


We hope you found our article on how long to wait after using an ozone generator useful and insightful.

While many people buy ozone generators for the purpose of making their indoor air smell better, you should be aware that ozone can be highly harmful to your health. It mainly causes respiratory issues, but other consequences can involve nausea, fatigue, and allergic reactions.

Before entering a room that is full of ozone, you should wait at least four hours after the ozone generator has stopped working. To switch it off, you can either set the timer to the desired number of hours, or you can return after a certain period and switch it off once the recommended number of hours has passed. Get informed about the recommended number of hours by reading the manual.

Also, in case of an ozone leak, remaining informed on how to detect it, as this should help you take adequate measures and leave no one in your household exposed to this toxic gas.