Light – two schoolgirls from Cologne made use of this gift of nature and, at the age of 17, pioneered the development of the first module for sterile escalator handrails.

"The handrails of escalators are one of the most common sources of smear infection in public spaces," says Tanja Zirnstein, Managing Director of Uvis UV-Innovative Solutions GmbH, which employs ten people.

Together with her former classmate Katharina Obladen, she founded Uvis in 2016. Since then, as the world market leader, they have been selling their Escalite product for disinfecting escalator handrails using UVC radiation internationally.

The idea was born in the 12th school year.

"We took part in the business project Business at School, in which we had the task of developing a product that is not yet available on the market," says Zirnstein.

"Since the swine flu was very present at the time and escalator handrails were considered to be one of the biggest sources of infection, we immediately thought of disinfection."

After an intensive search, they came across UVC radiation.

"This is cold and invisible radiation that is normally completely blocked by the ozone layer," explains Zirnstein.

"However, we can produce them artificially with lamps." The light is so short-wave that the DNA of microorganisms such as viruses, bacteria and fungi can be destroyed in a matter of seconds, rendering the germ harmless.

Disinfection with light has been in use for a long time

The longest escalator in Germany is in the Elbphilharmonie in Hamburg.

Gila Schuh from Hamburg also uses this regularly.

"When I recently found out that the handrail is supposed to be sterile, I was really excited at first," she reports.

But the fact that this is done with the help of light makes her skeptical.

"This behavior is not exactly uncommon in the population," says Adrian Mahlkow, scientist from Optotransmitter-Umweltschutz-Technologie e.

V. in Berlin.

He makes measurements for Uvis and builds prototypes.

"Disinfection with light has been in use for a long time and works well," he explains.

According to Zirnstein, this method has been used for decades.

"Yoghurt jars, returnable bottles and even drinking water are cleaned with light."

On the one hand, the disinfection is easy to regulate and can be automated without consumables such as chemicals, says Mahlkow.

On the other hand, you need an electrical connection and little public traffic.

Around 200 escalators in Germany have so far been equipped with the module.

"The Escalite module is half a meter tall," explains Zirnstein.

It includes three UVC lamps.

The handrail is irradiated from three sides in secret on the escalator and comes out again 99.99 percent germ-free.

It is very important that the radiation is bundled inside, as it causes severe sunburn in humans and also damages the DNA in the cells.

If UVC radiation gets into the eyes, the retina could be damaged.

"The power consumption is marginal," says Zirnstein.

The service life of the modules is unlimited, only the lamps have to be changed after around 12,000 hours of lighting.