Scientists step into ultraviolet lighting debate

A scientist in a face mask examines a test tube under ultraviolet light
At the specific wavelength of 222 nm, far-UVC lighting can be used to break down the RNA of the coronavirus and render it harmless.

LEADING scientists with expertise in ultraviolet lighting have stepped into the global debate on dealing with the coronavirus crisis.

The International Commission on Illumination (CIE) has decided to published a number of its key technical reports and international standards on the topic of ultraviolet lighting.

These publications will be freely available for the next three months as the body’s contribution to efforts to tackle the outbreak.

The publications include CIE document 155 on ultraviolet air disinfection and CIE document 187 on the risks from germicidal lamps.

It comes at a time when lighting professionals’ email inboxes and message feeds are filling up with offers of UV components and equipment.

Much of the marketing activity relates to UV-C, the potent part of the ultraviolet spectrum associated with germicidal properties.

UV-C has a wavelength of between 200 and 280 nanometers (nm) and is invisible to the human eye. 

It can be used for disinfection or purification as it breaks the DNA of micro-organisms (RNA in the case of the coronavirus) and makes them harmless.

Like the World Health Organisation, the CIE warns against using UV disinfection lamps to sterilise hands or any other area of skin.

Earlier this month Chinese transport authorities started using UV-C to disinfect their bus fleet to minimise infection while Signify, the world’s largest lighting company, says it is working with its partners in many countries to see how it can accelerate the use of UV-C lamps in those facilities where it can have a positive impact. 

It said UV-C had a ‘meaningful contribution’ to make to the situation: ‘UV-C radiation can be used to eliminate viruses, bacteria and moulds from water, air and surfaces’.

Mark Cunningham, developer of the recently launched Air-Lume air-purification luminaire, welcomed CIE’s announcement of the free issuing of documents but cautioned about the use of UV-C.

‘UV-C is a useful tool but has to be handled with great caution as the risk to users is significant if mishandled,’ said Cunningham. 

‘The race to sell UV-C LEDs by every one will replicate many of the errors of early LED use and proliferate the introduction of very dangerous junk products. 

‘The coronavirus outbreak should not create a scorched earth policy where we annihilate all micro-organisms by sterilisation, be that by UV-C or other methods.

‘We need bacteria in our environment and a knee-jerk reaction of obliteration will ultimately cause an equally damaging biological consequence.

‘After the pandemic, we cannot set out to annihilate all micro organisms.

‘We will all die without them’.

  • Download the CIE documents here: