UV sanitizers use powerful UV rays to get rid of infectious bacteria, fungi, and viruses, but are they safe?
Ultraviolet (UV) sanitizers use UV rays to sterilize surfaces. Research has found that UV sanitizers work, with some devices eliminating nearly 99.99% of bacteria, fungi, and viruses that cause disease. Uv Water Treatment
Some UV sanitizers are hospital-grade, tall fixtures with bulbs that emit UV rays for a set amount of time. UV sanitizers are also available as portable devices to cleanse personal items, such as phones, shoes, and toothbrushes.
Read on to learn about UV sanitizers, how they work, and whether they are safe to use.
UV sanitation is a disinfection method that eliminates microbes—bacteria, fungi, and viruses—without harsh chemicals or heat. UV is a type of electromagnetic radiation that produces light not visible to the naked eye. The most common source of UV is sunlight.
There are three types of UV light, which produce different wavelengths of light, including:
UVA and UVB rays may cause damage your skin and increase the risk of skin cancer if you are outdoors too long without protection, such as sunscreen. In contrast, the atmosphere absorbs UVC rays before they reach the earth's surface.
Manufacturers use UVC in UV sanitizers, available in artificial lamps and lasers.
Experts say that UVC rays with a wavelength of at least 254 nanometers eliminate 99.99% of microbes that cause disease.
UV sanitizers use UVC rays to damage a microbe's genetic material (i.e., DNA and RNA) so it cannot multiply. At shorter wavelengths than 254 nanometers, UVC rays may damage the proteins on microbes, so they cannot attach to your cells.
"[UV sanitizers] speed up cross-linking of this genetic material, which reduces the ability of the genetic material to participate in healthy replication," Karen Dobos, PhD, scientific director for the Regional Biocontainment Laboratory at Colorado State University, told Health.
Research has found that SARS-CoV-2, the virus that causes COVID-19, is vulnerable to UVC rays emitted by UV sanitizers. A study published in 2020 found that UV sanitizers can inactivate SARS-CoV-2 within nine minutes of exposure to UVC rays. Those results support other studies that suggest UVC rays can inactivate coronaviruses.
As a result, many hospitals have implemented UV sanitizers to disinfect areas during the COVID-19 pandemic. Still, the Environmental Protection Agency (EPA) does not list UV lights on List N, a list of disinfectant products the agency expects to work against SARS-CoV-2. More research is needed to understand the effects of UVC rays on SARS-CoV-2 fully.
In addition to hospital-grade UV sanitizers, manufacturers have created portable devices that disinfect small surfaces, such as phones, shoes, and toothbrushes.
Different types of UV sanitizers are available—from wands to zip-up pouches—to sanitize various items. For example, a wand might target household items like doorknobs, but a pouch might be more fit for small items like a phone.
Of note: Do not expose your eyes and skin to the UVC rays emitted by UV sanitizers, William Schreiber, PhD, chair of the department of chemistry and physics at Monmouth University, told Health.
A study published in 2020 looked at the effects of LightStrike, a far-UVC light, or a type of UV sanitizer used in hospitals. The researchers reported that LightStrike helps eliminate 99.99% of SARS-CoV-2 within one meter of the device within two minutes. Still, the researchers noted that far-UVC lights complement, rather than replace, other disinfectant methods.
Far-UVC lights do not deeply penetrate the eyes or skin, eliminating the risk of cataracts (cloudy lens of the eye), skin cancer, and other injuries.
UV sanitizers are available as portable devices that disinfect phones, which may carry infectious microbes. A study published in 2020 found that UV sanitizers are an effective, sustainable way to disinfect phones.
The researchers examined PhoneSoap, a UV sanitizer that envelops your phone and exposes it to 16 UVC bulbs. One 30-second cleaning cycle decreased the number of microbes by 90.5%, and two cleaning cycles eliminated nearly 99.9% of microbes.
Certain UV sanitizers help disinfect shoes, decreasing the risk of fungal infections. A study published in 2021 noted that UV sanitizers that use UVC rays at a wavelength of 200–300 nanometers effectively eliminate fungus on the soles of shoes.
Some UV sanitizers sanitize toothbrushes, which experts advise regularly disinfecting or replacing to decrease the risk of illness.
In a study published in 2014, researchers assigned a 2% chlorhexidine (CHX) mouthwash or saline solution to sanitize their toothbrushes for 12 hours or a UV sanitizer to use for seven minutes to 15 people. After seven days, the researchers collected the toothbrushes and studied the number of microbes on their surfaces.
The researchers found that the UV sanitizer was the most effective at significantly disinfecting the toothbrushes.
Research has found that hospital-grade and personal UV sanitizer may effectively and quickly disinfect surfaces. For example, UVC rays may eliminate nearly 99.9% of microbes on phones after one minute. Still, some factors may affect the effectiveness of UV sanitizers.
Using a personal UV sanitizer may do more harm than good in the long run. For example, antimicrobial resistance happens when microbes—bacteria, fungi, and viruses—adapt and change to become resistant to certain environments.
"[UV sanitizers] can be dangerous, especially with repeated exposure," noted Dobos. Many microbes will naturally have some adaptation or resistance to UV rays since they replicate and mutate faster than other organisms.
"This population of microbes will get greater and greater within your home, especially with repeated exposure," added Dobos.
Consumer products are likely less effective against microbes than industrial UV sanitizers since they have lower energy, said Dobos.
"The energy emitted from these bulbs has to be very low to be sold for personal use, which isn't the case for industrial applications," noted Dobos.
Some hospitals rely on UV rays to help sterilize surfaces. A study published in 2017 found that UVC light used in hospitals cut transmission of four major superbugs by 30%. Still, UV sanitizers for personal use may be less powerful than those.
The UVC rays emitted by UV sanitizer may lose their potency over time, too.
"As it decays, [UV sanitizer] becomes even less effective for its target, and I don't know how a person could tell how these bulbs are decaying," said Dobos. "I'm sure there's a 'replace by' date, but most of us only replace a light bulb when it goes completely out. This is well beyond the effective time for a UV source."
Research has not found that UV sanitizers damage phones. In contrast, disinfectant wipes are less environmentally friendly than UV sanitizers and may degrade phone screens.
If used unsafely, some UV sanitizers may increase the risk of health conditions, such as:
Certain UV wands may cause skin, eyes, or both injuries after a few seconds of use. Report any problems with a UV sanitizer to the manufacturer and the Food and Drug Administration.
Do not use products listed on the Food and Drug Administration's list of unsafe UV wands. Testing has found that those wands emit dangerous levels of UVC radiation, which increases eye and skin injuries.
You'll want to take extra precautions to avoid injuring yourself or others using UV wands. Only use UV wands with safety instructions. Ensure you follow all safety instructions for UV wands, especially those on protecting your eyes and skin.
Instead of UV sanitizers, other disinfecting methods help maintain clean, safe surfaces, said Dobos. Use a household cleaner that contains soap or detergent to decrease the risk of infection from surfaces in your home. Healthy air ventilation helps, too.
UV sanitizers help disinfect surfaces by inactivating infectious bacteria, fungi, and viruses. Portable devices—such as those that clean phones, shoes, and toothbrushes—may be less effective than hospital-grade UV sanitizers. Ensure that you follow precautions and safety risks when using UV sanitizers to minimize the risk of eye and skin injuries.
There are other ways to disinfect surfaces in your home. Cleaning with simple soap or detergent, having good air ventilation, and routinely disinfecting help maintain a healthy, disinfected home.
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