• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Power Electronic Tips

Power Electronic News, Editorial, Video and Resources

  • Products
    • Power Supplies
    • AC-DC
    • DC-DC
    • MOSFETS
    • Power Management
    • Battery Management
    • RF Power
    • Resistors
    • Capacitors
    • Magnetics
    • Transformers
  • Applications
    • LED Lighting
    • Rack Mount
    • Wireless
  • EE Forums
    • EDABoard.com
    • Electro-Tech-Online.com
  • EE Learning Center
    • Design Guides
      • WiFi & the IOT Design Guide
      • Microcontrollers Design Guide
      • State of the Art Inductors Design Guide
  • Video
    • EE Videos
    • TI Power Videos
    • Teardown Videos
  • Resources
    • Design Fast
    • eBooks / Tech Tips
    • FAQ
    • LEAP Awards
    • Podcasts
    • Webinars
    • White Papers

Study shows slightly safer UV-C wavelength kills Covid-19 bug

September 22, 2020 By Lee Teschler Leave a Comment

Hiroshima University researchers say Ultraviolet-C light with a wavelength of 222 nm effectively kills SARS-CoV-2. Other studies involving 222-nm UV-C have so far only examined how well it kills seasonal coronaviruses structurally similar to the SARS-CoV-2 but not on the COVID-19-causing virus itself.

light spectrum
Where 222 nm sits on the light spectrum.

Operation at 222 nm is said to be safer than emitting light at higher

study results
UH study results. Click image to enlarge.

UV-C wavelengths because such wavelengths cannot penetrate the outer, non-living layer of the human eye and skin. Although intense UV light at lower wavelengths can still be problematic for humans, the 222-nm range seems to be a safer alternative to the UV-C germicidal lamps used in disinfecting healthcare facilities which emit only 254-nm UV-C.

UV mercury lamps also have several other disadvantages: They can be fragile and thus risk mercury leakage if they break. Also, they take time to warm-up time and cannot exhibit maximum efficacy at low operating temperatures. In contrast, UV light-emitting diodes (UV-LED) can be configured to emit target wavelengths, not just the 254-nm seen from mercury lamps. Thus it looks as though it should be practical to devise UV-C-emitting LEDs that work at 222 nm.

The in vitro experiment by HU researchers showed that 99.7% of the SARS-CoV-2 viral culture was killed after a 30-sec exposure to 222 nm UV-C at 0.1 mW/cm2. The study is published in the American Journal of Infection Control. The tests used a Care222TM krypton-chloride excimer lamp. A 100 microliter solution containing the virus (ca. 5 × 106 TCID50/mL) was spread onto a 9-cm sterile polystyrene plate. The researchers allowed it to dry in a biosafety cabinet at room temperature before placing the Far-UVC lamp 24 cm above the surface of the plates.

The researchers, however, also say there’s a need for tests on real-world surfaces as their study only investigated in vitro efficacy.

 

You may also like:

  • face-shield-chamber
    Shedding light on how much UV-C you need for disinfection

  • When it comes to UV-C LED lights, buyer beware

  • Killing Covid-19 with UV-C LEDs
  • LEDs go purple
    Will LEDs go purple?

  • Don’t get burned about LED UV

Filed Under: Featured, LED Lighting Tagged With: engineering the crisis

Reader Interactions

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Primary Sidebar

CURRENT DIGITAL ISSUE

A frequency you can count on There are few constants in life, but what few there are might include death, taxes, and a U.S. grid frequency that doesn’t vary by more than ±0.5 Hz. However, the certainty of the grid frequency is coming into question, thanks to the rising percentage of renewable energy sources that…

More from the digital archive

DesignFast

Component Selection Made Simple.

Try it Today
design fast globle

Subscribe to our Newsletter

The Power Electronic eNewsletter delivers breaking electronic and power component news, resources, product innovations and more.

Subscribe today

EE TRAINING CENTER CLASSROOMS

EE Classrooms

RSS Current EDABoard.com discussions

  • Tuning the antenna to be conjugately matched to input impedance of the die
  • about ATmega328 ADC pins
  • Netlist physical name update
  • nt1065_USB3 gnss receiver
  • LLC HB with synchronous rectifiers can be very dodgy?

RSS Current Electro-Tech-Online.com Discussions

  • PC/laptop working and processing so much harder when data is low quality
  • undefined reference header file in proteus
  • Capacitor to eliminate speaker hum
  • Decapped Chip On Board
  • Sony KV-A2913E (chassis AE1C) auto shuts off after one minute

Footer

EE World Online Network

  • DesignFast
  • EE World Online
  • EDA Board Forums
  • Electro Tech Online Forums
  • Connector Tips
  • Microcontroller Tips
  • Analog IC Tips
  • Sensor Tips
  • Test and Measurement Tips
  • Wire and Cable Tips
  • 5G Technology World

Power Electronic Tips

  • Subscribe to our newsletter
  • Advertise with us
  • Contact us
  • About us
Follow us on TwitterAdd us on FacebookFollow us on YouTube Follow us on Instagram

Copyright © 2022 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy