Know Your Medicines
Clip-on Devices and COVID-19 Prevention?

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Several clip-on devices have been marketed to have protective effects against viruses and bacteria. They claim to release chlorine dioxide and reach concentrations around 0.017 ppm (parts per million)  to create a protective barrier for the user, although the exact mechanism of this release is not specified.

Chlorine dioxide is considered a toxic substance by most agencies including the Centers for Disease Control and Prevention (CDC) and World Health Organisation (WHO). In concentrations of 0.1ppm or higher, it can cause airway irritation leading to coughing, sore throat, severe headaches, and lung damage. Contact with skin and eyes may also lead to skin and eye irritation and burning. While the concentration of chlorine dioxide in these devices should be too low to cause these side effects, improper use or device malfunction may lead to harmful side effects as mentioned .

Chlorine dioxide gas has been used in some countries to disinfect healthcare facilities. This involves exposing a sealed room to toxic levels of 300ppm and above for several hours, much higher than possible with the clip-on devices. Hence without further information as to how the gas is released through these clip on devices, or evidence that such low concentrations sufficient to destroy the COVID-19 virus, it is highly unlikely that these devices will prevent COVID-19 infection.


  1. 2020. Ecom Singapore | ASK ECOM. [online] Available at: <> [Accessed 4 April 2020].
  2. 2020. ATSDR - Public Health Statement: Chlorine Dioxide & Chlorite. [online] Available at: <> [Accessed 3 April 2020].
  3. Centres for Disease Control USA- Occupational Health Guideline For Chlorine Dioxide. [online] Available at: < [Accessed 4 April 2020].
  4. Health Protection Scotland - Literature Review And Practice Recommendations: Existing And Emerging Technologies Used For Decontamination Of The Healthcare Environment - Chlorine Dioxide. [online] Available at: < [Accessed 4 April 2020].


Authored by

Annie Tran Anh Nhi, Choo Yan Cheng & Kng Li Lin, Grace
Members of Pharmaceutical Society of Singapore 

30th Mar 2020