Ozone generators are a standard solution for flood and fire restoration. A few homeowners also prefer ozone generators to other solutions for cigarette odor removal and eliminating attic odors.
Generally, ozone generators are effective in all these applications. Studies show that, in sufficient quantities, ozone can eliminate most airborne pollutants, leaving indoor air clean and healthy. Ozone can also work in water purification.
Unfortunately, ozone gas is hazardous. In high concentrations, it creates endless health risks, from itchy throat to decreased lung function. It can even cause shortness of breath.
Indeed, no health organization approves the use of ozone generators in occupied residential settings. The Environmental Protection Agency (EPA) also strongly warns against using any form of ozone treatments, whether air purifiers or ozone generators, in the home.
So, what if an ozone generator is your best way out? What happens if you’ve just bought a house only to find that the basement has a strong, persistent cigarette smoke odor that won’t dissipate no matter how much you run the AC with HEPA filters?
You can still use ozone generators. You just need to take greater precautions to protect yourself, the people you love, and your pets and plants. This guide discusses several safety precautions to help you use ozone generators without exposing yourself and others to the dangers of the gas.
What is Ozone?
Perhaps we should begin by understanding what ozone is, how it’s formed, and how ozone generators work.
Ozone is a gas that comprises three oxygen atoms. Introductory chemistry tells us that an oxygen molecule in its stable state comprises two oxygen atoms. However, ozone has a third molecule, which gives it the formula O3 instead of O2, which is the chemical symbol for stable oxygen.
How is it Formed?
The process of ozone formation typically begins with healthy, stable oxygen (O2) molecules. However, chemical reactions in the atmosphere can cause some oxygen particles to split, forming single oxygen (O) atoms.
Single oxygen atoms are highly unstable. They bond with pretty much any molecule or atom on sight. When these single oxygen atoms bond with stable oxygen atoms, they form a molecule with three oxygen atoms known as ozone.
This process happens naturally in the upper atmosphere (the stratosphere), thanks mainly to UV light. If you’ve heard about the ozone layer, it’s the result of natural ozone formation in the stratosphere. UV light has the potential to split stable oxygen molecules into single oxygen atoms.
How Do Ozone Generators Form Ozone?
Ozone generators form ozone molecules in two broad ways – UV radiation and corona discharge. The two processes work as follows;
The UV radiation process in ozone generators is similar to what happens in the stratosphere. The ozone generator introduces high-energy ultraviolet rays. When these UV rays strike stable oxygen molecules, they split the molecules into single oxygen atoms known as atomic oxygen. The highly unstable oxygen atoms easily pair bond with stable O2 molecules forming ozone gas.
An even better way to generate ozone gas is through corona radiation. Corona radiators are machines that rely on electrical discharge to split stable oxygen particles into atomic oxygen particles. This process is cheaper than UV radiation. It also produces more ozone particles than UV radiation. As a result, most ozone generators are silent corona radiators.
Ozone Generator Applications
Ozone generators have many applications. In residential settings specifically, an ozone generator can find use in the following scenarios;
- Removing attic odors: Musty attic odors result from years of accumulated dust and dirt with poor lighting and even worse airflow. Running the ozone generator for 2-4 hours in the attic can eliminate the odors.
- Eliminating cottage odors: After several months of being closed, the cottage can be smelly and musty. Skunk smells and the smell of dead animals can make the situation worse. Running an ozone generator in the area for 2-4 hours can resolve the problem.
- Removing mold and mildew: Mold and mildew odors are common in dark, damp areas such as basements. After removing the visible mold particles, you can run an ozone generator in the area to eliminate the associated odors.
- Removing pet odors: If you’ve experienced strong pet odors in the past, you’ll know that it can make the home unlivable. It’s actually one reason some people choose not to keep pets. An ozone generator can fix the problem.
- Removing strong cigarette odors: This is common when moving into a new house or after quitting cigarette smoking. You may want to get rid of the lingering smell. However, removing cigarette smell is no child’s play. Here too, ozone generators can be a lifesaver.
Dangers of Ozone Generator
Unfortunately, ozone gas is hazardous. According to EPA, breathing ozone gas in large quantities and for a prolonged period increases the risk of;
- Decreased lung function
- Respiratory infection
- Asthma attack
- Throat irritation and coughing
- Chest pains
- Shortness of breath
- Lung inflammation
Ozone Generator Safety Precautions
Owing to the many health risks and given that ozone, in high concentrations, can also damage plants and electrical wires, we recommend the following safety precautions (if you must use an ozone generator);
Pick the right ozone generator
Different applications require different ozone concentrations, thus different ozone generators. Ozone generators also vary in features. For instance, some have timers that you can use to program the treatment process. This way, you don’t need to return to the house to turn off the generator when the scheduled treatment period is over. Room coverage and switch methods also vary.
If it’s your first time purchasing/renting an ozone generator, consider reading a few buyer guides to compare options. You can also ask the seller or a renting company for guidance.
Read the owner’s manual carefully
Many manufacturers are very open about the dangers of ozone and outright warn their consumers about the risks of using ozone generators in residential spaces. Aside from the health warnings, you want to look for two things in the owner’s manual – how it produces ozone and how much ozone the generator produces per hour (concentration levels).
More powerful generators are inherently riskier because ozone poisoning is mostly about concentration levels. It means you must be even more careful.
Determine how much time you need to run it
Time is a critical factor in operating an ozone generator. Running the generator for 10 minutes less than necessary may leave the odor problem unresolved. On the other extreme, running it 10 minutes too long creates more ozone particles in your home, further increasing the risk of the health issues mentioned earlier.
Experts recommend running the generator for 2-6 hours per room, depending on the severity of the problem. This means that you may need to run it for 26-30 hours for whole-house treatment.
Evacuate the room before you begin
Begin by asking everyone to leave the room. Ideally, you want them out of the house for the period of the treatment. Then remove the pets and your plants. Plants need plenty of oxygen. The low oxygen levels in the house during ozone treatment can affect them adversely.
You also want to remove all valuable items from the area. Paints, in particular, tend to fade when exposed to high levels of ozone. Electrical wire sheathings may also be affected, so you want to tuck them away too.
Plan accordingly and proceed strategically
First off, remember that ozone is heavier than air. Therefore, you want to set the generator on the second floor for a multi-story home. Additionally, it helps to use the air conditioner and fans to disperse the ozone air throughout the home. That’s if you’re treating the entire home.
Above all, we’ve mentioned that most modern ozone generators have timers. Make use of the timer, so you don’t have to enter the room/house during treatment. Alternatively, find a mechanism to control the generator from outside the house. If you must enter the area during treatment, cover your mouth and nose with a towel so that you don’t breathe the harmful gas.
Wait before you re-enter the area
How long to wait before re-entering the home after an ozone generator treatment is a hotly debated topic. However, what’s not debatable is that ozone is highly unstable and will seek to return to a stable state as soon as possible. In many cases, the third oxygen atom is lost within as little as 30 minutes. Then the single atoms pair up to form stable oxygen molecules.
However, this doesn’t necessarily mean you should re-enter the room after 30 minutes. We recommend waiting at least 2-3 hours for low-concentration ozone applications and up to 4-6 hours for high concentration applications. Some professional technicians even ask families to stay out of the house for two full days after whole-house ozone treatment.
What Else Do You Need to Know?
The only other thing we want to add is that ozone is flammable. At elevated temperatures and in the presence of specific catalysts, such as hydrogen, copper, chromium, and iron, it decomposes explosively. It also oxidizes at much lower temperatures than regular oxygen and the oxidation process evolves more heat, meaning it can ignite without warning.
For the above reasons, do not use ozone in an environment with flammable gases or explosives. Also, smoking, open fires, or working with objects that may produce spark or flames is prohibited around the treatment area.