The COVID-19 pandemic changed a lot- including our perception of health and wellness. This change accelerated the popularity of air purifiers and clean air initiatives. With increasing awareness of airborne transmission of viruses, people are seeking solutions to ensure their indoor air is as clean as possible. Maintaining a germ-free home can often feel like an insurmountable challenge, but that is where negative air ions (NAI) come in. These naturally occurring particles are invisible to the naked eye but pack a powerful punch when it comes to blocking contaminants. 

Waterfalls are a natural source of negative ions
Waterfalls are a natural source of negative ions

Everything You Need to Know About Negative Air Ions 

Air ions are molecules with an electrical charge. They’re unseen molecules that drift around in the air. Negative ions are molecules that have gained an electron, while positive ions are those that have lost an electron. An air ionizer is a device that emits negative ions into the air that attach themselves to tiny particles, like those in tobacco smoke or other air pollutants. The negative ions are attracted to airborne particles, causing them to gather and cluster together into larger, heavier particles. These larger particles fall out of the air faster, cleansing the air of unwanted pollutants.  

Using NAIs for disinfection and to slow the spread of airborne pathogens has been studied heavily and has been shown to be safe. Negative air ions have been shown to inactivate and block aerosol transmission of viruses and bacteria [4][5][6][7]. Additionally, a2018 review of NAI literature published in the International Journal of Molecular Science found consistent evidence that: 

  • NAIs can significantly reduce inhalable dust counts and particulate matter from the air. 
  • NAIs can kill or inhibit the growth of harmful bacteria, viruses, and mold species. 

While NAIs are incredibly beneficial for air purification and overall health, it’s important to address a common concern associated with air ionizers: ozone emission.   

Air Ionizers and Ozone Emission 

While air ionizers are revered for their air purifying capabilities, it’s essential to consider their ozone output. Some ionizers are designed to manage their ozone production with HEPA filters or other mechanisms, preventing excessive ozone release into the environment. Many will show testing that complies with the strict limitspublished by the California Air Resources Board (CARB).  

However, these filters or mechanisms are not without their downsides, and they require regular maintenance and replacement to remain effective. Neglecting to replace or clean a filter can lead to severe respiratory issues as the ozone output increases, and one inhales airborne pollutants that can no longer be effectively filtered out. According to U.S. Environmental Protection Agency, recent studies have shown that the efficiency of filters with permanent electrostatic fields drops significantly when the filters become dirty.1  

Furthermore, these filters can significantly increase the total cost of ownership of the air ionizer. Therefore, while filtered air ionizers can be a great choice for those seeking cleaner indoor air, they require careful and regular upkeep to ensure they are safe and cost-effective.   

In conclusion, the safety of air ionization is largely based on the specific product and its operation. While air ionizers can effectively purify the air by removing dust, allergens, and bacteria, they can also produce ozone, which can be harmful to human health when present in high concentrations. Therefore, it’s crucial to choose an air ionizer that has been thoroughly tested and certified to not produce harmful levels of ozone. Among the products available, the AURA Ion Bar™ is set apart by its superior performance and commitment to ozone safety, ensuring a healthy and safe indoor environment while effectively purifying the air. 

Learn more about Ion Bar here.


  1. Indoor Air Quality (IAQ) | US EPA 
  2. Air purifiers in demand amid COVID-19 Delta surge, wildfires – Los Angeles Times ( 
  3. What is a HEPA filter? | US EPA 
  4. Hagbom, Marie et al. “Ionizing air affects influenza virus infectivity and prevents airborne-transmission.” Scientific reports vol. 5 11431. 23 Jun. 2015, doi:10.1038/srep11431 
  5. Zhang, Cheng et al. “Aerosol Transmission of the Pandemic SARS-CoV-2 and Influenza A Virus Was Blocked by Negative Ions.” Frontiers in cellular and infection microbiology vol. 12 897416. 29 Apr. 2022, doi:10.3389/fcimb.2022.897416 
  6. Comini, Sara et al. “Positive and Negative Ions Potently Inhibit the Viability of Airborne Gram-Positive and Gram-Negative Bacteria.” Microbiology spectrum vol. 9,3 (2021): e0065121. doi:10.1128/Spectrum.00651-21 
  7. Escombe, A Roderick et al. “Upper-room ultraviolet light and negative air ionization to prevent tuberculosis transmission.” PLoS medicine vol. 6,3 (2009): e43. doi:10.1371/journal.pmed.1000043 
  8. Jiang SY, Ma A, Ramachandran S. Negative Air Ions and Their Effects on Human Health and Air Quality Improvement. Int J Mol Sci. 2018 Sep 28;19(10):2966. doi: 10.3390/ijms19102966. PMID: 30274196; PMCID: PMC6213340.