The COVID-19 pandemic has fundamentally changed many of our practices and attitudes regarding infection control.
Hand hygiene was one of the earliest and most widely adopted measures to prevent the spread of disease, but there are more technology-based approaches.
Read more: Vodka won’t protect you from coronavirus, and 4 other things to know about hand sanitizer
An example is the booming industry of devices that use ultraviolet radiation (UV) to kill germs. While UV can successfully sterilize items like air, or your smartphone, it can also come with the risk of cancer if the radiation isn’t behind a proper barrier.
Here’s what you need to know about UV cleaning equipment.
How does UV cleaning work?
Ultraviolet light is light with wavelengths so short that most humans cannot see them under normal conditions. The most common source of UV is the sun, which emits everything from vacuum UV to UVC, UVC, UVB and UVA rays (see below).
The last two can pass through the ozone layer in our atmosphere, while the first three are blocked – good news for life on Earth, as UVC can be particularly harmful to living organisms.
At wavelengths of 250-260 nanometers, the energy produced by UVC rays can penetrate microbes to break their DNA and RNA, disrupting their cell functions and killing them.
It is useful for sterilizing (germ-killing) UVC radiation technology, although its effectiveness depends on the intensity of the radiation, the distance from the light source to the target, the type of surface to be disinfected, and the wavelength at which the UVC works. Is.
The blue light you often see on such devices is either decorative, or visible light emitted from the chemicals used to make UVC – remember, UV light itself is invisible.
According to research, cleaning devices that emit high doses of sterilizing UVC are an effective means of killing fungi, viruses, bacteria and protozoa – single-celled organisms. They have been successfully used in the treatment of water, air, sewage, food safety, medical settings, public transport, etc.
The key is that the UVC source is completely enclosed and automatically shuts off if the device is open, so there is no risk of exposing people to radiation, which can cause severe burns and cancer. It can also increase the risk of
UV cleaning gadgets that work without a wall present serious health risks. Unfortunately, the current lack of regulation means that such devices are readily available for consumers to buy – and potentially cause harm.
Severe lack of regulation
A number of companies have researched and developed safe, efficient and fully enclosed UVC equipment.
However, the market is unregulated, with serious concerns about the quality and safety of some dubious devices available to consumers. In 2020, lighting industry body the Global Lighting Association expressed its concerns:
“[I]Amid the global COVID-19 pandemic, the GLA is concerned about the proliferation of UVC disinfectants – particularly those sold over the internet – with dubious safety features and inadequate safety instructions”.
Read more: Ultraviolet light can make indoor spaces safer during pandemics – if used correctly
Unwalled UVC products, like the “disinfection sticks” you see on the Internet, can be very unsafe. They can infect exposed skin, eyes, and mucous membranes.
Because of the health risks, any unattached UVC device should be remote-controlled or automated only. It should also be equipped with safety measures, such as a sensor that turns it off when it detects someone in the room.
To ensure the safety and efficacy of UVC equipment available on the consumer market, we urgently need watchdog bodies to introduce stricter global regulations.
Is UVC safer?
Recently, UVC has been proposed as a potential solution to this challenge. Far UVC has a “shallow” penetration of the skin, emitting at wavelengths of 207-222 nanometers. However, research with UVC is very recent and so far has focused mostly on animals.
Very few human studies have been performed, and some have been funded by companies prototyping a lot of UVC equipment, which may introduce bias. Literature search reviews report different analytical parameters, making comparisons difficult.
Some trials have begun, but are still few, and with small sample sizes.
We will need trials with strict ethical approvals to investigate the full effects of UVC on humans. There is a lack of understanding to what extent UVC may affect people with thin skin layers, cuts, photosensitivity, or various medical conditions.
Read more: Ultraviolet radiation is a powerful disinfectant. Maybe our schools, hospitals and airports need it.
What to look out for if you still want a UV cleaning device
Buyer beware when it comes to buying UVC gadgets. Never buy anything that claims you can disinfect your hands, body, or entire room when people are around. Skin cancers such as basal cell carcinoma and squamous cell carcinoma are attributed to UV exposure.
Check the documentation. Is there evidence that this device is effective against microorganisms? What is the length of exposure, and is the target being sterilized?
You also need to know that efficient and safe new technology and efficient UVC producing LEDs are very expensive. Therefore, you may need to question the effectiveness of a relatively “cheap” device.
In the absence of a global regulatory body on the UVC market, the rule of thumb is to simply buy a fully sealed, closed UVC device that works with strict safety and efficiency to harm microbes, not you.