Disinfection for hygiene areas: germ-free thanks to a UVC LED illuminated box

The Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB has developed a UVC LED disinfection box that has been specially designed for use in sensitive areas such as laboratories, clean rooms and clinics.

In an interview with COMPAMED-tradefair.com, project manager Thomas Westerhoff explains the challenges, solutions and advantages of this technology.

Mr. Westerhoff, what problems motivated you to develop the UVC LED disinfection box? 

Thomas Westerhoff: We have been working in a large research network funded by the BMBF since 2013 to further develop UVC LED technology. At that time, UV LEDs were low-power and not durable enough to serve as a replacement for mercury lamps. 

In collaboration with the Institute for Hospital Hygiene at Jena University Hospital, we investigated how we could solve typical hygiene problems in hospitals with UV radiation. One focus was on the disinfection of small electronic devices, such as tablets, access cards and medical equipment, which often pass from hand to hand and can therefore transmit potentially pathogenic germs. 

What technical challenges did you overcome during development? 

Westerhoff: The biggest challenge was to make the irradiation homogeneous and therefore uniformly effective. UVC radiation only works through direct illumination. The efficiency of disinfection is proportional to the radiation dose. Shading, for example by using gratings as a shelf, led to inadequate results. We have therefore developed a special transparent glass plate that prevents shading. In addition, we coated the interior of the box with a reflective and scattering polymer to distribute the radiation evenly. These optimizations enable very efficient disinfection.

How does disinfection with the box work in practice? 

Westerhoff: The disinfection box is slightly larger than a microwave. Employees place the object to be disinfected – a tablet, for example – in it and press a button. Disinfection is completed within around 30 seconds. At the same time, employees can change their clothes or carry out other hygiene measures. This saves time and is much more thorough than conventional wipe disinfection, which often leaves behind residues and cannot be validated. 

What advantages does UVC LED technology offer over chemical disinfection methods? 

Westerhoff: One of the biggest advantages is its environmental friendliness. Chemical disinfectants, especially aggressive substances such as quaternary ammonium compounds, pollute the environment. Our solution only requires electricity. In addition, LEDs have a longer service life than mercury lamps, are immediately ready for use without a heat-up phase and enable targeted irradiation. Operating costs are also low, as no consumables such as disinfectants are required.

Can you say something about the results so far? 

Westerhoff: We have tested the device in collaboration with Boehringer Ingelheim. We were able to achieve an irradiation dose of 500 joules per square meter within 33 seconds, which led to an inactivation of more than 99.999 % of the bacteria tested. We were even able to achieve good results with difficult pathogens such as spore formers. Boehringer is now successfully using the device in airlocks for laboratories. 

Are there any special requirements for using the device in laboratories or clinics? 

Westerhoff: No, it is compact and easy to use, like a microwave. All it needs is a power source. This flexibility also makes it suitable for smaller laboratories. 

What are the next steps in your project? 

Westerhoff: We want to further optimize the technology and develop additional applications in the field of surface disinfection. There is still a lot of potential, and we are looking forward to driving forward the efficiency and sustainability of hygiene technology.