ECJ EUROPEAN Cleaning Journal

In the wake of lockdown businesses are looking for reliable and safe methods to reopen and there is rapidly growing interesting in how UV-C disinfection technology can maximise the effectiveness of regular cleaning regimes. What do we know about it, and how can it help in tackling the current situation? UV-C disinfection products specialist Golden Sea UV writes exclusively for ECJ.

In the new landscape emerging from the global COVID-19 pandemic, the need for reliable control of harmful viruses is of paramount importance. The potential health threats posed by the ubiquitous presence of viruses, bacteria and mould call for a fast and reliable means of disinfection to help minimise transmission. The current coronavirus crisis has brought this into sharp focus and the role of cleaning companies has become a key part of the fight back against the virus.

The need for safety and confidence

The recent changes in government guidelines mean businesses, hospitality services and workplaces of all kinds are eager to open their doors, kickstart their businesses back into life, and start to recoup some of the losses inflicted by the Covid-19 pandemic. In the wake of lockdown businesses are looking for fast, reliable and safe methods to reopen and operate that ensure the safety of staff and clients, regain the trust of their customer bases and rebuild customer confidence.

New challenges call for new approaches, and there is rapidly growing interest in how UV-C disinfection technology can maximise the effectiveness of normal cleaning regimes. Tests show that UV-C disinfection is a fast, safe, efficient and proven technology that kills or deactivates 99.9 per cent of bacteria and viruses, including Covid-19, and is particularly effective when used in combination with normal cleaning practises to minimise bacterial and viral spread.

What’s more, employing UV-C technology as the final component in your new cleaning regime, avoids the hazards and disadvantages of chemical sprays, such as surface damage, high running costs and exposure of staff to hazardous substances, and reduces the risk of cross contamination due to poor/inconsistent cleaning practises or accidental transmission.

Ultraviolet disinfection lamps are extremely efficient and very convenient to operate, especially when compared to familiar disinfection methods that use liquid and powder-based disinfectants. Frequently-used rooms and public areas of all sizes can be kept clean and free from virus, quickly and economically. UV-C disinfection lamps can be deployed in a wide range of domestic and commercial environments: hotels, chalets, caravans, self-catering and bed and breakfast accommodation; restaurants, cafes, offices, factories, schools, gymnasiums, clinics; theatres, conferences and event spaces – anywhere, and in any business, that cares about the welfare of staff and customers.

Tried and tested

UV-C disinfection, or germicidal ultra-violet irradiation (UVGI) as it is known, is not a new technology. UVGI has been studied since the late 19th century, with UV-C becoming a particular focus around 1930. In 1935 scientists revealed through demonstration the ability of UV-C irradiation to effectively inactivate airborne micro-organisms, and in the 1970s it was proven to reduce TB infection.

Since the early 1990s there has been further focus on the efficacy and safety of UV-C products as a way to inactivate viruses and bacteria, which have since become useful tools in the fight against infection. The technology remains in practise to the present day where UV-C disinfection is widely used in hospitals as part of standard disinfection protocols.

Multiple scientific reports show high efficacy rates in the reduction of harmful micro-organisms, for example: “Implementation of this ‘no-touch’ technology in various hospitals has documented a sustained reduction in surface microbial contamination, reduced cross contamination and a reduced spread of multi-drug resistant bacterial infection.

In the study of Liscynesky et al. [15], in rooms of patients with confirmed C. difficile  infection (CDI), 32 our ot 238 (13 per cent) high-touch surfaces were positive after bleach disinfection and only one out of 238 (0.4 per cent) was positive after UV-C treatment (the computer keyboard) at 254nm emitted by three  connected devices run for 45 min.” [Evaluation of an Ultraviolet C (UVC) Light-Emitting Device for Disinfection of High Touch Surfaces in Hospital Critical Areas, Beatrice Casini et al, Sep 24 2019].

Recent research by Boston University School of Medicine, working with leading lighting manufacturer Signify (previously Philips) Lighting, confirms that UV-C radiation, applied in sufficient doses, successfully inactivates SARS-CoV-2, the virus that causes Covid-19. Signify has shared this technology with other lighting companies, enabling manufacturers to develop new products in a bid to help limit the spread of Covid-19. Only 253.7nm UV-C light sources manufactured by Signify and Osram are validated as effective against SARS-CoV-2, so look for brands that utilise these sources.

What is UV and UV-C?

Ultraviolet light is a form of radiation and an invisible part of the electromagnetic spectrum. It has a wavelength between 100nm-380nm. UV-C with a wavelength of 200nm-280nm has proved to be the most effective disinfectant wavelength in the UV Spectrum.

How does UV-C work?

Surfaces exposed to UV-C light are disinfected because UV-C (in particular 253.7nm) destroys the molecular structure of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) of microbial (bacteria and virus) cells, causing the death of growth cells and/or regenerative cells, thus achieving the effect of disinfection. Strictly speaking, bacteria are destroyed and viruses are inactivated as viruses are not ‘alive’ and therefore cannot be ’killed’. Exposure to UV-C causes a photochemical reaction when the radiation is absorbed. Damage to the microbe’s DNA ensues and the action of the absorption of the photon makes the bacteria/virus unable to replicate.

How can UV-C help tackle Covid-19?

The efficacy of UVC-disinfection protocols at inactivating viruses like SARS-Cov-2 – as proven by Boston University and numerous other studies – depends on the UV-dosage delivered over time. Consequently, manufacturers are producing UV-C lighting products for domestic/consumer and commercial/industrial use with products designed specifically for the disinfection of surfaces, objects and the air, in rooms and spaces of all sizes.

Surface disinfection can be achieved with a variety of wall-mounted or freestanding models tailored for the needs of venues from small rooms to large industrial units. Disinfection times vary according to the size of area being disinfected, and all personnel, animals and plants must be removed from the site while disinfection is undertaken.

UV-C disinfection requires direct exposure to be effective, and very few spaces have clear lines of sight in all directions, so most manufacturers recommend the use of multiple units positioned in different areas to eradicate shadow lines and ensure increased levels of disinfection. For this reason, manufacturers also recommend that UV-C products are used in conjunction with other disinfection protocols for a whole area approach to ensure the highest levels of disinfection.

Cabinet-style products can be used to disinfect smaller household and office items in daily use such as mobile phones, headsets, office stationery, make-up tools, face masks and other small items.
Air purification solutions, which bring the same peace of mind and effectiveness as surface cleaners, combat the virus in aerosolised form. Circulating air is taken in and purified before being returned to the room. Products can be ceiling mounted for upper air purification, or free-standing, and have the advantage of continuous use, even when people are present within the space. An ACH (Air Change per Hour) of between six and10 times is recommended.

Little training needed

The process can be extremely cost-effective with maximum returns on a single, affordable investment: because UV-C technology does not rely on chemicals, there are no further overhead costs on chemicals, cleaning fluids or additional manpower. This also increases UV-C’s environmental credentials as, without chemicals, it leaves no residue or by-products, and therefore has little environmental footprint. There are no hazardous fumes or associated wait-times for dissipation of fumes, so cleaning times can be massively reduced with rooms and public areas disinfected and ready for use often within an hour - guaranteeing a fast turnaround between guests, for example.

How safe is the technology?

UV-C is very well researched and well understood. Compared with UV-A and UV-B, both of which are present in sunlight, UV-C presents little penetration into deeper layers of skin. In fact, UV-C primarily impacts and is absorbed by the outer dead layer and outer skin. However, exposure to UV-C can cause temporary skin and eye irritation/redness and longer exposure can cause burns. For this reason, all personnel, animals and plants must leave or be moved from site during use as a primary precaution (except with certified air purification units). It is also worth noting that UV has a degrading effect on many materials, including plastics, paper and cloth, so exposure over time may cause surfaces to change colour or become more brittle.

To ensure safe operation, all good UV-C products come with full in-built safety features – look for those that include a motion sensor, audio alarm, start delay and remote control and other
visual indicators.

Those manufacturers who go the extra mile also provide extra safety features like UV-filtering glasses, warning signs for the operator to place on the door of the area being disinfected, full user guides and a comprehensive training programme. And of course, all products should be CE, ETL and FCC compliant and listed.

As we come through this global pandemic with every industry looking for ways to rebuild their business in a rapid, safe and responsible way, UV-C disinfection can play a part in helping you to safeguard the working environment for your staff and regain the trust of your customer base by providing them with the safest possible space to work in and congregate.

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