UV air purifiers are safe.
Are UV Air Purifiers Safe?
Most UV air purifiers are safe to use on a daily basis with no chemicals byproducts and insignificant levels of ozone emission under the 0.050 ppm limit certified by the California Air Resources Board (CARB). However, Ozone (O3) can still be dangerous as it is a highly reactive gas composed of three oxygen atoms. Created during the UV irradiation, exposure even to a small amount of ozone can lead to chest pain, coughing, shortness of breath, wheezing, and throat irritation. In the long run, it can cause irreversible damage to our respiratory systems like pneumonia, bronchitis, asthma attack, and lung scarring with reduced capacity. Children, elderly, and asthmatic people will be more susceptible to ozone so use cautiously.
The Hidden Danger With UV Purifiers
Besides the ozone concern, improper handling of UV air purifiers can do more harm than good. Direct exposure to ultraviolet light can lead to skin burning, eye damage/ photokeratitis, premature aging, and skin cancer. Here are few easy tips on how to use a UV sanitizing device safely:
- Never sterilize your hands or any part of the skin with UV light according to World Health Organization (WHO) guideline.
- Avoid unreliable, poorly made UV air purifiers that have the tendency of leaking harmful UV during irradiation.
- Do not let children or pets go near a UV air purifier.
- Never stare directly at ultraviolet light. Never point the UV light at other people as well.
- Avoid purchasing aftermarket UV lightbulbs or lamps that may not follow the FDA Ultraviolet Index (UVI) safety ratings.
- CDC recommends installing UV disinfection in ductwork or at the ceiling to complement the existing air filter rather than replacing it.
- For commercial use, make sure you are properly equipped or suited to operate special UV devices.
What Is UV light?
Ultraviolet light is a form of electromagnetic radiation invisible to the eye. Derived mainly from the sun rays, there are three types of UV light (UVA, UVB, UVC) that vary in frequencies and wavelengths. UV-A has the longest wavelength between 315 to 400 nm, follow by UV-B with a wavelength between 280 to 315 nm. UV-C has the shortest wavelength between 100–280 nm with the fastest vibration and energy level. You will find UV technology used in commercial applications such as hospitals, healthcare centers, beauty salons, meat processing plants, factories, and laboratories. Most sterilizing devices including air purifiers use the broad-spectrum UV-C light because it is the most effective in disinfecting biological pollutants by destroying their DNA. The artificial germicidal light will also genetically damage COVID-19 RNA render it harmless.
The Effectiveness Debate
Another setback with UV technology is the efficiency. While there is no doubt UV air purifiers can kill and inactivate germs, bacteria, viruses from multiplying, it is unlikely the microbes will remain exposed in the internal UV chamber for minutes to an hour. The pathogens will have to be close proximity to the UV light bulb in order to be fully sanitized. Some microorganisms strain like mold is highly resistant to UV radiation that may even take a longer time to kill off. There is also the ultraviolet light intensity, cooling effect of airflow, the size, and material of the lightbulb that can affect the UV irradiation performance.
The lack of standardized UV measurement against airborne pollutants is another common issue. There are manufacturers that sell inferior products yet make up fake claims on the UV effectiveness just to trick people into buying one. You should only purchase a UV air purifier from a reputable manufacturer approved by CARB and AHAM.