Breathe Easy: Filtering Ozone At Home

Ozone is a harmful air pollutant and respiratory irritant that is mainly formed from outdoor pollution emissions. While ozone in the upper atmosphere is beneficial as it shields us from ultraviolet radiation, ground-level ozone can be dangerous to breathe. Indoor air pollution from ozone can be very dangerous to people's health, and many are unaware of the dangers of ozone exposure and its common sources. Fortunately, there are several methods to filter out and reduce ozone air pollution at home.

Avoid using ozone-generating air purifiers

Ozone-generating air purifiers are not recommended for use by the California Air Resources Board (CARB) and the U.S. Environmental Protection Agency (EPA). CARB advises against using ozone generators in spaces occupied by people or animals, and only recommends them for approved industrial purposes where harmful exposure to ozone is prevented.

Ozone-generating air purifiers are ineffective at cleaning indoor air and pose serious health risks for humans and animals. Inhaling ozone can irritate and inflame the lining of the respiratory system, causing symptoms such as coughing, chest tightness, shortness of breath, and impaired breathing. It can worsen asthma symptoms and may even contribute to the development of asthma. Repeated exposure to ozone can increase the risk of adverse health effects, especially in vulnerable groups such as children, the elderly, and people with pre-existing respiratory conditions.

Ozone is a highly reactive gas that can create additional toxic pollutants, such as formaldehyde and ultrafine particles, when it interacts with other chemicals indoors. It is important to note that ozone concentrations below health standards are not effective in removing most indoor air contaminants, including odour-causing chemicals. Ozone can also deaden one's sense of smell, making it difficult to detect high ozone levels.

Instead of relying on ozone-generating air purifiers, it is recommended to use proven methods of controlling indoor air pollution. These include eliminating or controlling pollutant sources, increasing outdoor air ventilation, and using effective air cleaning methods such as air filters with activated carbon, exhaust fans, and mechanical ventilation systems.

By following these recommendations, you can effectively reduce indoor air pollution and protect the health and well-being of yourself and your family.

Use air filters with activated carbon

Air pollution from ozone can be extremely harmful to human health, especially for those with pre-existing conditions such as asthma, children, the elderly, and those who spend a lot of time outdoors. Ozone generators, which are often marketed as air purifiers, can actually increase ozone levels and cause serious health issues.

To combat this, air filters with activated carbon are highly effective at removing ozone from indoor air. Activated carbon filters are a common component of many air purifiers and HVAC systems. The porous structure of activated carbon contains millions of tiny pores and tunnels. As the air passes through, pollutant molecules are trapped in these pores through a process called adsorption, where the molecules stick to the surface of the pores via intermolecular forces.

Activated carbon is especially effective at trapping gases and odors. It can adsorb a wide array of gases, making it ideal for general air purification and ozone removal. In controlled studies, activated carbon filters have been shown to reduce ozone levels by up to 90%. This is a significant reduction, ensuring that ozone levels remain in a safe range.

When choosing an air filter with activated carbon, it is important to consider the replacement of the filters. Manufacturers typically recommend replacing activated carbon filters every 2-3 months, but this may need to be sooner if there are pets in the home, smokers, or if using ozone generators. Check the specific product specifications for guidance on replacement intervals.

In addition to using air filters with activated carbon, it is also beneficial to employ other strategies to reduce ozone levels and improve indoor air quality. Adequate ventilation is crucial, including opening windows and using exhaust fans near pollutant sources, such as above stoves when cooking. Increasing outdoor air ventilation through mechanical ventilation systems can also help dilute indoor air pollutants.

Increase ventilation by opening windows

Opening windows is an effective way to increase ventilation and reduce indoor air pollution, assuming the area you live in is not heavily polluted. By drawing in outside air, you can reduce the concentration of indoor air pollutants, including ozone.

When increasing ventilation through open windows, it is important to be mindful of the source of pollutants. If the source of ozone is outdoors, such as on warm and sunny days with little to no wind, it is advisable to keep the windows closed. However, if the source of ozone is indoors, such as from certain devices or appliances, increasing ventilation by opening windows can help dilute and disperse the ozone, reducing its concentration indoors.

To further enhance ventilation and pollutant dispersal, consider using exhaust fans near pollutant sources. For example, you can turn on the exhaust fan above your stove while cooking to remove ozone and other pollutants generated during the cooking process. If your home is equipped with a central forced-air system, upgrading the filter to at least MERV 13 can also improve ventilation and filtration.

Additionally, be mindful of cross-ventilation techniques. Opening windows on opposite sides of your home can create a natural airflow, drawing fresh air in from one side and pulling polluted air out from the other. This simple technique can effectively increase ventilation and help reduce indoor ozone levels.

In summary, increasing ventilation by opening windows is a valuable strategy to reduce indoor ozone pollution. However, always consider the source of the pollutants and the outdoor air quality before opting for this method. Combining window ventilation with other strategies, such as exhaust fans and upgraded filters in central air systems, can further enhance the effectiveness of ozone reduction in your home.

Use exhaust fans near pollutant sources

Exhaust fans are an effective way to reduce indoor air pollution. They are particularly useful in rooms where pollutants are generated, such as the kitchen or bathroom. When showering or cooking, use an exhaust fan to expel pollutants directly outside before they can negatively impact other rooms. For example, a vent hood over a kitchen stove can remove pollutants generated from cooking.

Exhaust fans can also be used in conjunction with windows to improve their effectiveness in removing pollutants. Opening a window may not always be enough to clear the air, especially on warm, calm, or humid days. Therefore, using an exhaust fan at the same time can help to increase the airflow and improve indoor air quality.

If you are installing a new exhaust fan, look for an ENERGY STAR-qualified fan. These fans are energy-efficient, provide the right airflow, and are quiet. For bathrooms 100 ft2 or less, the fan should be 50 cfm to provide the right ventilation without wasting energy.

In addition to exhaust fans, there are other mechanical systems that can be used to improve indoor air quality. For example, mechanical filters trap particles on the surfaces of porous media, acting like three-dimensional sieves. These filters vary in shape and the size of the smallest particles they can trap, as measured by MERV (Minimum Efficiency Report Value).

Overall, using exhaust fans near pollutant sources is an effective way to reduce indoor air pollution, especially when combined with other methods such as opening windows or using mechanical filters.

Avoid ozone-generating devices

Ozone-generating devices are often advertised as air purifiers that can improve indoor air quality. However, these devices can be harmful to your health and are not recommended for use.

Ozone is a highly reactive molecule composed of three oxygen atoms, making it unstable and potentially toxic. It is a major component of smog and can irritate and inflame the lining of your respiratory system, causing symptoms such as coughing, chest tightness, and impaired breathing. People who are particularly vulnerable to ozone exposure include children, the elderly, those with asthma or other respiratory diseases, and those who spend long periods outdoors.

Some vendors of ozone generators claim that their devices have been approved by the federal government and are safe and effective at controlling indoor air pollution. However, these claims have been refuted by health professionals for almost a century. No federal government agency has approved ozone generators for use in occupied spaces, and organisations like the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) actively advise against their use due to the health risks.

Ozone generators purposely emit large amounts of ozone, which can react with other molecules in the air to create additional toxic pollutants, such as formaldehyde and ultrafine particles. They are also ineffective at removing most indoor air contaminants, including particles that cause allergies, such as dust and pollen. While ozone can be used to purify water, this is because people are typically not present when it is used, reducing the risk of exposure.

To improve indoor air quality, it is recommended to use proven methods such as eliminating or controlling pollutant sources, increasing outdoor air ventilation, and using air cleaning methods like air filters and gas-absorbing materials.

Frequently asked questions