For much of the late 20th century, science assumed it understood light and its influence on living systems. In hindsight, that confidence was misplaced. The discovery in 2002 of intrinsically photosensitive retinal ganglion cells (ipRGCs) – non-visual photoreceptors in the human eye that regulate our internal body clock – opened a new chapter in lighting science. Suddenly, illumination was no longer just about visibility or energy efficiency. It became a question of biology. (By: Urbain du Plessis of Verdantek*)
At the same time, the rapid rise of LEDs made it possible to isolate and control narrow bands of the light spectrum at low cost. Researchers across disciplines began exploring how specific wavelengths could influence everything from mood and metabolism to plant growth and sterilisation. Among these findings, one stood out: the surprising disinfecting power of visible blue light.
From crop science to clean air
Before the pandemic, I worked with research teams at AgrioBio – a leading agricultural biosciences centre in Melbourne – to develop advanced models to optimise crop yields under controlled environmental conditions. The work included studying how plants and microbes respond to the full light spectrum. Meanwhile, scientists in Finland were experimenting with light-based air disinfection systems for cleanrooms.
When COVID-19 reshaped global priorities, these two lines of research converged. The challenge was clear: find safe, sustainable, and continuous ways to disinfect air, water, and surfaces without the collateral damage caused by traditional chemical or UV-based methods.
Beyond ultraviolet
Ultraviolet light has long been used to purify air and water – ancient Egyptians even used sunlight to clean linen – but its limitations are well known. UV can degrade plastics, coatings, and fabrics, creating ideal conditions for bacterial biofilms to thrive. It also poses health risks to humans, making it unsuitable for continuous use in occupied spaces.
Blue light, on the other hand, offered a gentler yet powerful alternative. Microbiologists had already observed its antimicrobial effects, but early systems demanded either high energy levels or catalytic coatings that required frequent maintenance.
Then came a breakthrough. Finnish researchers identified an optimal combination of blue wavelengths that achieved the same disinfection performance as UV, at lower energy levels and without catalysts. The result was antimicrobial blue light (aBL), a globally patented technology now used in healthcare, aviation, food production, and defence.
Proven in the air and on the ground
LINDO, a key partner in this development, was among the first to commercialise aBL systems. In 2021, the Air Ambulance of Victoria adopted LINDO’s blue-light disinfection chamber for sanitising patient stretchers. The system delivered exceptional microbiological results and cut turnaround times so dramatically that it paid for itself within a year. By 2024, LINDO had developed roll-on aBL units for aircraft interiors, offering continuous, low-maintenance protection in one of the most demanding operational environments.
Both Boeing and Airbus are now collaborating with LINDO on integrated lighting-disinfection systems for passenger aircraft. The technology is also proving its worth in search-and-rescue helicopters, where aircrew and patients operate in close quarters under high exposure risk. LINDO’s multifunctional lighting units combine aBL disinfection with night-vision-compatible deep red and high-quality white task lighting – an elegant, all-in-one solution showcased in the Airbus mock-up at the recent Aeromed conference.
Safe, efficient, and scientifically verified
Blue light’s antimicrobial action is not a new discovery, but its application has evolved. More than 2,000 peer-reviewed studies confirm its ability to kill bacteria, yeast, and mould, including multi-resistant strains like MRSA and VRE, as well as viruses such as SARS-CoV-2 and Influenza A. Unlike UV, aBL works through transparent materials and can even penetrate biofilms – without fostering microbial resistance.
The mechanism is elegantly biological. When exposed to certain blue wavelengths, naturally occurring light-sensitive compounds inside microbial cells – such as porphyrins and flavins – become excited. This triggers a chain reaction that generates reactive oxygen species (ROS), which in turn destroy DNA, RNA, proteins, and cell membranes from within. Because human and animal cells lack these compounds, they remain unaffected.
The patented multi-wavelength, high-intensity design of LINDO’s aBL systems activates multiple absorption pathways simultaneously, achieving faster and broader disinfection than older single-wavelength (405 nm) solutions. It can sanitise air, surfaces, and equipment in minutes rather than days, and operates safely in continuously occupied spaces.
Tested and certified
LINDO’s blue-light systems comply with rigorous international safety standards, including IEC 62471:2006 and IEC TR 62778:2014 (Blue Light Hazard). Classified as Risk Group 1 (Low Risk), these devices pose no hazard to eyes or skin during normal use and require no special labelling or protective measures.
By contrast, conventional disinfection methods – chemical sprays, UV radiation, or hydrogen peroxide misting – cannot be used continuously. They are hazardous to people and materials, require manual application, and their protective effect vanishes as soon as the space is reoccupied.
Continuous protection for a changing world
The key advantage of antimicrobial blue light is its safety and constancy. It can operate continuously, even in the presence of people, delivering ongoing disinfection without damage or downtime. While the intense blue hue can be distracting for some, automation systems easily alternate between standard lighting and disinfection mode, ensuring effortless, around-the-clock hygiene.
The most effective disinfection is the one that never stops. I am already working with local manufacturers on aBL availability.
*About the author
Urbain du Plessis is a globally experienced lighting and technology leader with over 30 years of living and working abroad across Australia, Europe, and Asia. Beginning his career at Zumtobel in 1988, he went on to design lighting for Olympic stadia, develop the F1 night racing specification, and bring over 1,000 products to market. Having held C-level roles in multinational firms and managed sales across 50 countries, Urbain’s expertise spans lighting, IoT, polymers, acoustics, and advanced materials. Returning to South Africa, he brings global insight, 30+ patents, and a record of innovation, leadership, and industry contribution.
