Are Ozone Generators And Ozone Air Purifiers Safe?
Understanding What Ozone Generators Are And Why They May Not Be The Safest IAQ Solution.
Ozone generators are popular air-cleaning devices that have become more widely used since the COVID-19 pandemic created awareness of the need for cleaner air in occupied spaces. However, ozone has been known to have detrimental health effects on humans when exposed to specific concentrations for extended periods. Therefore, when considering ozone generators for air cleaning, realize they must be operated with great care as ozone generating electronic air cleaners can emit unsafe ozone levels.
What Are Ozone Generators?
Ozone Generators are a type of air purification system that produces Ozone (O3) to help reduce the presence of airborne contaminants. Ozone's highly reactive composition of three Oxygen atoms allows the molecules to attach to airborne organic contaminants to oxidize and eliminate them. There are both good and bad forms of ozone:
Stratospheric ozone, or “good ozone,” is found in the atmosphere between 6 and 30 miles above the Earth’s surface. The ozone layer shields us from harmful UV radiation from the sun. Ozone at the ground level, or “bad ozone,” is an air pollutant harmful to our health. Ozone generators typically produce “bad ozone.”
Are ozone generators safe?
Unfortunately, no. The EPA has denounced these devices and cites several scientific studies showing they can be harmful to health and ineffective at removing airborne contaminants. That is why no federal agencies have approved ozone generators for use in occupied spaces.
How Does an Ozone Generator Work?
Ozone is composed of three atoms of oxygen, hence O3. Two atoms from the oxygen we breathe; the third can detach from the ozone molecule, reattach to molecules of other substances, and change their chemical composition.
Ozone generators harness that chemical reaction by filtering oxygen (O2), then using an electrical charge to break apart oxygen molecules, encouraging them to reform as oxygen and ozone.
There are two methods used to generate ozone:
- Silent corona discharge: This method is an electric discharge that encourages the molecules to split (as mentioned above). When the molecules reattach, they form ozone or oxygen. This method produces more ozone and is more efficient than an ultraviolet generation.
- Ultraviolet (UV) radiation: This method is like the process of stratospheric ozone creation. These ozone generators use UV radiation to split oxygen molecules apart. However, this method is less effective than silent corona discharge.
Ozone and Health
Just as ozone reacts with organic material in the air, it can react with organic material in our bodies, leading to health problems. When inhaled, ozone directly affects our lungs and respiratory system. It can cause airway hyper-responsiveness, including shortness of breath, wheezing, and coughing. In addition, if you have a lung condition, like chronic obstructive pulmonary disease (COPD) or asthma, ozone can exacerbate it. Potential health risks from ozone include:
- Decreased lung function.
- Aggravated asthma.
- Throat irritation and cough.
- Lung tissue inflammation.
- Higher susceptibility to respiratory infection.
- Chest pain and shortness of breath.
Long-term ozone exposure happens when you inhale ozone for more than eight hours a day over weeks and months. This type of exposure has been linked to the risk of hospitalization for asthma and numerous respiratory-related conditions.
When it comes to ozone-generating devices, there are rules and guidelines for how much ozone can be emitted by a product and how long workers can be exposed to certain amounts. Here are some recommendations for human exposure to these devices (see the Clean Air Act):
- The EPA’s national standards for ozone (which fall under National Ambient Air Quality Standards per the Clean Air Act) is an indoor ozone concentration of 0.070 ppm for 8 hours over an annual period.
- Recommendations from NIOSH suggest that 0.10 ppm should never be exceeded.
- Additionally, OSHA requires that workers not be exposed to an average concentration of 0.10 ppm for 8 hours.
- Finally, the FDA limits some indoor medical devices to no more than 0.05 ppm.
Risk factors are largely determined by the ozone concentration, the duration of exposure, the activities during exposure, and pre-existing conditions (like asthma).
Ozone Generators vs. Ionizers
Ozone generators are often lumped in with ionizers. However, while ionizers are also air-cleaning devices, they work by electrically exciting ions in the air, encouraging them to latch onto air particles, which eventually get collected by the device.
Ionizers are known to remove pathogens and viruses, but they are not effective at eliminating odors and volatile organic compounds (VOCs). Since many odors are VOCs, including smoke, pet smells, and mold, ionizers will not work if you need to remove odors or these types of particles.
The EPA’s Take on Ozone-Generating Air Cleaners
There is great debate about air cleaners such as ozone generators and ionizers, the health effects of these devices, and whether the indirect or direct ozone output can be harmful. The EPA took this to heart, especially since there is much material— primarily produced by manufacturers—that claims ozone is not necessarily harmful to your health.
After conducting a study, the EPA came to several conclusions about ozone generators, including:
- The chemical reaction that ozone needs to be effective requires months or years to take place. Therefore, unless you have an ozone generator running for a long time in a building with no inhabitants, its usefulness is questionable.
- Once the ozone can react, there is a chance that the chemical reaction will produce irritating products. For example, in a study that mixed ozone with chemicals in a new carpet, ozone reduced the smell and presence of some substances, but it also produced aldehydes, which can be toxic.
- Ozone does not remove particles from the air, but ionizers do. However, ionizers are said to not be as effective as HEPA filters at removing particles like smoke, pollen, and mold (although they can latch onto viruses and pathogens).
- When ozone generators are used at a level deemed healthy, they are not effective at reducing odors.
Are Ozone Generators Worth It?
Ozone generators are not a safe choice for cleaning the air in occupied spaces. However, the device can be helpful when used in uninhabited areas for a long time, such as cleaning up natural waste. The room should be as closed off as possible for the generator to work and ventilated before the space is reoccupied.
Since ozone can be harmful to human health, companies need to be careful how the devices are used. In addition, ozone generators can take months to work. Therefore, if you are looking to improve the indoor air quality of your business by running it overnight, it will be a waste of time and money.
How Do Ozone Generators Compare To Other Air Purification Technologies
Want to learn more about ozone generators and how they compare to competing electronic air purification technologies? Then visit our most recent blog "The Difference Between Hydroxyl Generators, Ozone Generators, And Bi-Polar Ionization."
Finding the Right Air Cleaner for Your Business
When it comes to your inhabited workplace, ozone generators do not fall under best practices for indoor air quality. Even if manufacturers say the device does not produce ozone in hazardous amounts, do your research and try to identify how much ozone the device emits. You will also need to pay attention to the square footage the device was tested in compared to the size of your space. If a very large room is required to run the ozone generator effectively, smaller businesses may not be feasible.
Instead, opt for a multi-stage air cleaner that does not produce ozone, or if it does, it is generated indirectly and in small amounts. It would be more advantageous—and safer—to get an air purifier that can operate while people are in your building. You can also take advantage of additional filters (like HEPA filters), UV-C light technology for killing viruses, and activated carbon filters for removing VOCs. Contact us to get started with a customized plan to clean your air effectively and safely.
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