It takes 30 minutes to about two hours for the area to be free of ozone particles for low-concentration applications. However, it can take slightly longer, up to four hours, for ozone to dissipate following high-concentration applications.
However, if you’re asking because you want to know when it would be safe to return to your house or room after an ozone generator treatment, the figure is slightly higher. You may be asked to stay out of the house for up to two days following a high-concentration treatment.
Let’s discuss more on ozone, how it works, and its applications in home settings to determine why you should wait longer and what other precautions you need to take to protect your health.
What is Ozone?
Ozone is a highly reactive gas comprising three oxygen atoms. It’s both a natural and human-made product. Naturally occurring ozone is typically found in the upper atmosphere (the stratosphere), while man-made ozone is mainly found in the lower atmosphere (the troposphere).
Stratospheric ozone is formed naturally through the interaction of UV light from the sun and molecular oxygen. It’s what scientists are talking about when they mention the ozone layer. The ozone layer is found six to thirty miles away from the earth’s surface. Although it has its downsides, the ozone layer is critical for human life and other forms of life on earth. It limits the amount of UV light reaching the earth.
The type of ozone that worries environmentalists and everyone else concerned about life on earth is tropospheric ozone. Tropospheric ozone is man-made. It’s formed mainly from photochemical reactions between volatile organic compounds (VOCs) and nitrogen oxides (NOx). When inhaled, it react s with various molecules in the respiratory tract, potentially causing a range of health issues.
Sources of Ozone in Residential Settings
According to the International Journal of Environmental Research and Public Health, there are two main sources of ozone in residential settings;
- Outdoor sources: This category covers all ozone particles that enter the home through natural ventilation, mechanical ventilation, and infiltration through cracks in the building structure.
- Indoor sources: This category includes ozone molecules creates through photochemical reactions inside the home. Examples include photocopying, air purifying, disinfecting devices, and, above all, ozone generators.
One of the most common sources of residential ozone is air purifiers intended to control indoor air pollution. Ozone air purifiers are intended to work by altering the charge of particles or air pollution. Changing the charge allegedly causes the particles to attract each other, forming new, harmless molecules. Air purifiers are typically marketed as ionizers.
Unfortunately, the high-voltage systems used to ionize the air also convert some oxygen particles into ozone. The lingering, unstable oxygen (O) atoms from so-called pollutants can attach to stable oxygen (O2) molecules in the air, forming unstable ozone (O3) molecules.
An even more dangerous source of ozone, however, is ozone generators. As the name suggests, ozone generators are specifically designed to produce substantial volumes of ozone gas. Potential applications of these generators include air purification, water purification, and odor removal. Ozone generators are especially common in cigarette odor removal.
Ozone generators work by splitting healthy oxygen (O2) molecules into single oxygen atoms (O). The unstable oxygen atoms then attach to healthy oxygen molecules to form ozone molecules with three oxygen atoms. The process can be achieved through silent corona discharge or UV radiation.
Whichever method is used to generate the ozone molecules, manufacturers argue that the unstable molecules quickly release single oxygen atoms that bind to cigarette odors and other nicotine particles. This process changes the molecular structure of nicotine and nicotine products, effectively removing cigarette smells and associated odors.
Fairly Effective, But the Risks are High
The good news is that ozone is fairly effective in all the applications above. Whether in air purification, water purification, or cigarette smells, and other odor removal applications, ozone generators, and air ionizers guarantee pretty good results.
Studies show that strong ionizers can remove most airborne and water-borne pollutants. Ozone generators are also largely effective against odors and other airborne pollutants when used in high concentrations.
Unfortunately, the keyword in both cases is – high concentrations. Ionizers and ozone generators are weak and largely ineffective in low concentrations. You need high concentration levels to achieve the desired results.
And that’s where the trouble begins!
A high ozone concentration poses significant risks to you, your loved one, and even your pets. Too much ozone in the air can also affect plant life and damage electrical wire plastic covers. According to the Environmental Protection Agency (EPA), potential risks to human health include;
- Induction of respiratory
- Decrement in lung function
- Inflammation in the airways
- Throat irritation
- Pain and discomfort in the chest
- Wheezing and shortness of breath
How Long Does it Take for Ozone to Dissipate?
The good news is that the unstable nature of ozone means it cannot survive long in an area with an abundance of natural airflow. Soon, the third oxygen atom breaks away and combines with another single oxygen atom from a different ozone molecule to form a stable oxygen molecule.
But there’s one issue – it doesn’t happen straight away. It can take a bit of time, sometimes hours, for the entire room or house to be rid of ozone particles.
The general recommendation is to wait at least 30 minutes after a low-concentration and up to four hours for a high-concentration application. For most applications, most ozone particles will have disintegrated to form stable oxygen molecules.
However, you may have to wait even longer following a whole-house ozone treatment for nicotine odor removal. According to experts in the field, a whole-house treatment to remove nicotine odors and other effects of long-term cigarette use in the house can take up to 8 hours.
In fact, you’ll realize that the large ozone generators have timers that run for up to nine hours for this purpose. After running an ozone generator for nine hours in your home, you may be required to wait two full days before returning to the house.
Remember, however, that it’s impossible to rid an area of ozone particles. Even healthy indoor environments have a few ozone particles lurking around. According to the Air Now, an EPA project, healthy air contains anywhere between 0-50 ozone levels. At this level, the air quality is rated “Excellent,” and the ozone poses no risk at all.
Therefore, you may want to measure the ozone levels before returning to the house. This can be especially helpful following a high-concentration ozone treatment that lasted several hours. Ozone sensors, meters, and detectors exist explicitly for this purpose.
In a nutshell, we learn that ozone is a hazardous, unstable gas that occurs naturally but can also be man-made. Though it protects us from direct exposure to cancer-causing UV light from the sun, too much of it in the lower atmosphere can cause severe health issues, including respiratory illnesses and compromised lung function.
However, ozone from air ionizers or ozone generators can also be effective in air purification, water purification, and removal of stale odors, including strong nicotine smells.
Given the health risks, it’s critical to wait at least 30 minutes to 4 hours after ozone treatment before returning to the room or house. You may even need to stay away for two whole days following a high-concentration, whole-house ozone treatment.