UV air purifiers use short-wave ultraviolet light (UV-C) to kill viruses and bacteria in the air. UV-C wavelength highly damages viruses and living creatures as it reaches DNA molecules. This type of UV-C air purification can directly expose people in the same room to ozone.
Ozone can break down natural tissue, such as lung tissue, posing a risk to people with respiratory issues. We do not recommend you use this type of technology. We always recommend you opt for a regular air purifier equipped with HEPA and Activated carbon filtration.
When the pandemic was in full swing, we were advised to disinfect groceries and clean door handles after each touch to avoid surface transmission. But research later determined that surfaces were an unlikely transmission route for most people.
Many studies concluded that airborne transmission was the main way that SARS-CoV-2 spread.
So the primary focus for air purifier companies was to show how their products could kill and remove the virus from the air.
UV air purifiers were one such solution. These air purifiers for the home appeared after it was discovered that UV light helps prevent the spread of hospital-acquired infections during the Covid-19 pandemic.
But rather than cleaning the air and improving your health, UV purifiers can be dangerous and cause irreversible health problems if they produce Ozone.
This article will cover how UV air purifiers work and the associated risks.
UV Air Purifiers and Their Associated Health Risks
Before we get into UV Purifiers and the risk involved, we should know what UV light is. We all know the dangers of UV-A and UV-B from sunbathing:
|😎 UV-A gives you a good tan|
|🥵 UV-B can give you severe sunburn|
UV-C is not mentioned often because the earth’s ozone layer absorbs it before it reaches us. But science being what it is, UV-C light has been created artificially and used.
You may have read that a UV Air Purifier will kill viruses and bacteria floating in the air around your home.
UV-C is large enough to kill bacteria and viruses, but it is still very early to be used in commercial devices.
A 2021 systematic review found that UV air purifiers using a HEPA filter may effectively remove bacteria from the air. In a lab experiment, they could see that UV-C combined with HEPA and alone could help reduce viral count. UV-C alone had no effect on particle count and required in combination with HEPA to reduce this.
So what’s the big problem? The main problem with this type of technology is that it can leak UV light which can cause damage to any living thing. To avoid this, many manufacturers use very low-powered UV-C lights that don’t create dangerous amounts but are useless for killing viruses and bacteria.
UV can also cause Ozone
Different wavelengths will adjust the amount created, but any ozone can be a risk to people with respiratory issues and is something you want to avoid in your home.
According to the Environmental Protection Agency, ozone can cause chest pain, coughing, throat irritation and airway inflammation. Children, people with asthma and older adults are more likely to be negatively affected by ozone.
|✅ INDUSTRY ADVICE|
The Environmental Protection Agency (EPA) recommends not buying any air purifier that emits ozone. Instead, they recommend using upper-room UVGI devices fitted by professional HVAC experts and combined with HEPA filter-based air cleaners – see our list of what we think are the best air purifiers for bacteria and viruses.
How Do UV Air Purifiers Work?
UV air purifiers harness the power of UV-C light to inactivate airborne viruses and bacteria by altering or damaging their DNA.
If you have ever had sunburn, you know the sun’s UV rays’ effect on your skin. The DNA in your skin cells has been damaged, causing sunburn.
As we said above, UV air purifiers do not kill viruses; they merely damage them to the extent they cannot reproduce, which is how a virus spreads. A virus is not a living organism but is made up of DNA and RNA, which it uses to infect the DNA of other cells.
When viruses have been subjected to UV-C light, their DNA and RNA are inactivated, preventing them from invading healthy organic cells.
Bacteria, on the other hand, are single-cell living organisms. Their DNA is essential to stay alive. As bacteria passes through the UV air purifier, its DNA is bombarded with UV-C light damaging the DNA so that it cannot perform two main functions—transcription and replication.
This prevents the bacteria from multiplying, spreading and forming colonies throughout your body, the source of infections.
To be effective, a UV air purifier must be equipped with the right technology and produce UV light at a specific wavelength and intensity to inactivate any virus or bacteria.
Read our detailed report for further information on UV-C air purifiers.
Danny’s Verdict: HouseFresh Doesn’t Recommend
“This technology represents a clear danger of UV radiation for skin and eyes. Like Ionziers from 10+ years ago, UV-C can also create ozone and, through interaction with other chemicals, it will create VOCs and worsen your air. Most UV air purifiers on the market are too low-powered to clean your air with UV-C, and you are much better with a HEPA-based air purifier. Due to this, we advise you to avoid UVC-based air purifiers.”
UV-C lights incorporated in consumer air purifier models are widely regarded as ineffective. Furthermore, they’re unsafe as they produce ozone. To seriously affect airborne pathogens, it is considered better to have a HEPA air purifier which will incapacitate the smallest bio-contaminants and pathogens, such as bacteria and viruses.
Lewis, D. (2021). COVID-19 rarely spreads through surfaces. So why are we still deep cleaning? nature.com
Greenhalge, T et al. (2021). Ten scientific reasons in support of airborne transmission of SARS-CoV-2. thelancet.com
Institution of Mechanical Engineers. (2021). Hospitals to use UV air cleaners to tackle COVID-19 after IMechE develops standard for NHS. imeche.org
Hammon, A et al. (2021). Should homes and workplaces purchase portable air filters to reduce the transmission of SARS-CoV-2 and other respiratory infections? A systematic review. plos.org
Brazier, Y. (2019). Bacteria: Types, characteristics, where they live, hazards, and more.medicalnewstoday.org
Environmental Protection Agency. (2023). Ground-level Ozone Basics. epa.gov
Steadman, N. (2021). Asthma Symptoms: 7 Signs of Asthma You Ignore. thehealthy.comEnvironmental Protection Agency. (2018). Portable Air Cleaners and Furnace or HVAC Filters in the Home.epa.gov