How to Safely Use UV-C For Germicidal Disinfection

How Safe is Ultraviolet-C (UV-C)?

UV-C has been proven useful in the fight against numerous bacteria, viruses, and mold. But how safe is it?

As the world comes to terms with the first great global pandemic in recent times, technology like UV-C disinfection lighting will play an ever more important part in our keeping us safe now, and into the future.

At UVClean, we've talked about UV-C in our blog and social media in recent months and we’ve received one question more than any other: is it safe? So, in response, here’s a quick breakdown of how UV-C works and how it can be used in an effective and safer way to keep our shared spaces disinfected and hygienic.


How UV-C Disinfection Works

UVClean's UV-C products produce ultraviolet light to inactivate microorganisms like viruses and bacteria, making them harmless to humans. UV-C disrupts the DNA or RNA that enables those viruses and bacteria to multiply. It’s been used safely and effectively in commercial sanitization of water, hospitals, and food, for more than 40+ years.

UV-C Is Naturally Produced By The Sun!

There are three type of UV radiation produced naturally in sunlight. There’s UV-A and UV-B, which you may recognize from sunscreen labels. UV-A and UV-B cause sunburn and signs of skin ageing like wrinkles and age spots, and even skin cancer.

We don’t come into contact with UV-C because it is filtered out by the ozone layer in the Earth’s atmosphere. The wavelength of UV-C light is shorter than the wavelength of the light we can see and spans the range of 100-280 nanometers (nm). It is most effective at inactivating viruses on or around 260-265nm, known as the ‘germicidal peak.’ UVClean's UV-C lamps operate at 254nm, which is proven to be highly effective in inactivating viruses, bacteria and mold spores. 

Humans and animals should not be exposed to germicidal UV-C light at this wavelength as it can cause damage to their skin and eyes in a matter of minutes1 of exposure. Proper protective equipment and must be used when operating germicidal UV-C products. That said, provided that our UV-C products are used and installed correctly and in accordance with our user manuals and mounting instructions, UV-C is a reliable and highly effective form of disinfection, with safety risks mitigated by the appropriate safeguards put in place.

Safety Precautions

Where safety precautions are needed is during direct exposure of surfaces to a UV-C light source. To prevent damage to eyes or skin resulting from direct exposure to UV-C room sanitizing light sources, no people or animals can be present during a UV-C surface disinfection cycle. For smaller handheld sanitizing devices, care must be taken to avoid direct contact with UV-C light against unprotected skin or eyes. As added level of safety, safety googles, gloves, or protective clothing should be used.
While UV-C light cannot pass through protective surfaces, including windows, extra levels of safety are provided in certain devices that use infrared sensors that can switch the UV-C light sources off if they detect people or animals.

Safety Standards

The global pandemic has accelerated the development and use of UV-C disinfection products across the globe. With that in mind, it’s essential that companies involved in the production and roll-out of germicidal UV-C lighting adhere to the highest safety standards. The Global Lighting Association has developed guidelines for manufacturers and users of UV-C disinfection products that focus on increasing the safety of products for their users. UVClean's UV-C products are developed and designed to meet the high standard set by this new guidance.

UV-C’s Effectiveness Disinfectant

"All micro-organisms that have been tested so far for UV-C exposure were shown not to be resistant to
UV-C light”

UV-C is very effective, and has even been proven effective in inactivating the airborne virus responsible for the global pandemic³. All micro-organisms that have been tested so far for UV-C exposure were shown not to be resistant to UV-C light. Additionally, Boston University recently tested germicidal UV-C light sources on the virus responsible for the global pandemic. The team applied a dose of 5mJ/cm2, resulting in a reduction in the virus of 99% in 6 seconds. Based on the data, it was determined that a dose of 22mJ/cm2 will result in a reduction of 99.9999% in 25 seconds.

To further eliminate the risk of infection, UV-C can be used in combination with other disinfection methods like traditional scrubbing using chemical disinfectant.  In high contact areas such as a gym, restroom or hospital treatment room, such additional safeguards ensure that areas that are shaded from the reach of the UV-C light are also disinfected.

"There are instances where UV-C can be applied where other methods of disinfection can’t”

Equally, there are unique instances where UV-C is advantageous and can be applied where other methods of disinfection can’t. For example, it’s very useful for disinfecting drinking water, or objects like mobile phones that are impractical to submerged in liquid chemicals.
Germicidal UV-C lighting is a powerful and quick form of disinfection, and by ensuring that the appropriate safeguards are put in place and that users and operators utilize proper safety precautions, UV-C disinfection can be safely used as a well-established means of chemical-free disinfection.


1 Timing depends on the power of the UV-C source and proximity of the person to it. For most applications it is 1-2 minutes, although it can be shorter.

2 Other than medical devices.

3 Buonanno, M., Welch, D., Shuryak, I. et al. Far-UVC light (222 nm) efficiently and safely inactivates airborne human viruses. Sci Rep 10, 10285 (2020). 

⁴ The time it takes to disinfect depends on the power of the UV-C source and proximity. Disinfection times vary with these parameters.


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