Let there be ‘UV’ light…

Researchers have developed portable disinfection chambers that use ultraviolet light to sterilise PPE kit

Portable disinfection chambers that use ultraviolet light to inactivate virus particles could quickly disinfect personal protective equipment, researchers report. The chambers could benefit those who need PPE in the fight against COVID-19, including emergency medical technicians, police officers, health care workers, pharmacy technicians, and others.

Researchers built two prototype chambers to evaluate PPE disinfection using different sources of UV-C light: mercury vapour lamps and light-emitting diodes (LEDs). They used the prototypes to evaluate different power levels and disinfection times with a variety of face shields and face masks used to protect workers from the coronavirus.

“There are trade-offs in terms of cost, lifetime, and potential heat generated,” says T. Robert Harris, a research engineer at the Georgia

Tech Research Institute (GTRI). “We wanted to evaluate these issues so that when others use UV-C for disinfecting PPE, they will have information to make good choices.”

The researchers wanted to provide disinfection chambers as small as possible to allow for portability. They built the chambers to accommodate face masks and at least one face shield—a curved sheet of clear plastic that covers the entire face and protects against large droplets that could contain coronavirus. The portability of the chambers could allow their use anywhere PPE disinfection is needed.

“We wanted a box that would fit on an ambulance or in a police car so that public service staff who are coming into contact with a lot of people on a regular basis would be able to disinfect their PPE,” Harris says. “This method offers an advantage over chemical disinfection because it doesn’t require drying time or risk of chemical absorption.”

Originally, the project aimed disinfecting PPE while it was being worn by having health care workers walk past an ultraviolet source while going from one hospital room to another. That idea was dropped because the wavelengths needed to inactivate the virus—280 nanometers—can cause skin and eye damage in humans. For that reason, the prototype portable disinfection chambers include a safety interlock to prevent the door from being opened while the UV light is on.