BfS advises caution when disinfecting with UVC

UV disinfection chamber Source: LeafenLin / iStock / Getty Images Plus

In the view of the Federal Office for Radiation Protection (BfS), caution is required when using UVC disinfection devices to combat the coronavirus SARS-CoV-2.

Given that UV radiation can damage the skin and eyes and has also been shown to be carcinogenic, UVC disinfection devices should only ever be used in a way that prevents human exposure to radiation. This also applies to devices that emit short-wave UVC, also known as "far UVC".

Current discussions

In light of recent scientific publications, discussions are ongoing as to whether disinfection devices that emit short-wave UVC radiation in the 222-nanometre region carry fewer risks than the devices with wavelengths around 254 nanometres (nm) that are currently on the market. This is based on the reduced depth of penetration into the eyes and skin at wavelengths of 222 nm.

However, the scientific assessment of the possible health consequences is still in the early stages.

BfS will monitor developments

President of the Federal Office for Radiation Protection, Dr Inge Paulini

The President of the Federal Office for Radiation Protection, Inge Paulini, said: "As yet, the available research findings do not allow a reliable assessment of the extent to which shorter-wavelength UVC radiation poses a smaller risk. It’s also unclear whether the devices that are currently on the market actually only utilise this type of UVC radiation with shorter wavelengths of around 222 nanometres."

The BfS will evaluate the latest insights into the effects of shorter-wavelength UVC radiation and closely monitor whether these applications are also suitable for use in the presence of human beings – including to combat the coronavirus.

UVC radiation

The natural source of UVC radiation is the sun. As this type of radiation is completely filtered out by the atmosphere, no natural UVC radiation reaches the surface of the earth.

UVC--Ultraviolet C has long been used to disinfect air, water and surfaces, as well as foodstuffs. Generally, this form of disinfection is used when no one is present in the room or when the source is installed in such a way that anyone present is not exposed to radiation. These applications are unproblematic from the point of view of radiation protection.

No use of UVC on the body

However, Paulini pointed out that UVC radiation should never be used for disinfection on the body. When it comes to the disinfection of air and surfaces, she said: "If the use of UVC devices is unavoidable, it is vital to ensure that the skin and eyes are protected from the radiation."

Recommendations

The BfS neither examines the effectiveness of UVC disinfection lamps nor issues product recommendations.

However, the BfS does recommend that those opting to buy a UVC disinfection device take note of the manufacturer's information when purchasing the equipment. This information should be as complete and specific as possible. For example, it should include details of the device's effectiveness – in other words, for how long and from what distance objects must be irradiated in order to achieve an actual reduction in the quantity of active microorganisms. Information should also be provided about the wavelengths and intensity of UV radiation emitted, and the manufacturer should clearly substantiate any promises relating to the effectiveness of the equipment.