Another thread on HN [22705511] points to a press release from
a company making a product that uses UVc light to disinfect
breathing air. What kind of UVc light is not disclosed, but a
search of the website hints at their product using 254 nm light.
Making clean air sounds good, but we should ask: Does it also
make ozone? I thought this might be worth checking.
Ozone is pretty toxic even in low concentrations. The recommended
and permissible exposure limit is 0.1 ppm [1] as set by both OSHA
(Occupational Safety and Health Act) and the NIOSH (United States
National Institute for Occupational Safety and Health).
In looking for information about ozone generation by UVc
I found the explanation on the Oxidation Technologies website.
They wrote a clear explanation for non experts that answers
our question. It appears 254 nm light dissociates ozone to
pure oxygen. That would be a statistical result rather than
absolute. That is want I want to share here without interfering
with the HN discussion on disinfection.
Comments
Another thread on HN [22705511] points to a press release from a company making a product that uses UVc light to disinfect breathing air. What kind of UVc light is not disclosed, but a search of the website hints at their product using 254 nm light.
Making clean air sounds good, but we should ask: Does it also make ozone? I thought this might be worth checking.
Ozone is pretty toxic even in low concentrations. The recommended and permissible exposure limit is 0.1 ppm [1] as set by both OSHA (Occupational Safety and Health Act) and the NIOSH (United States National Institute for Occupational Safety and Health).
In looking for information about ozone generation by UVc I found the explanation on the Oxidation Technologies website. They wrote a clear explanation for non experts that answers our question. It appears 254 nm light dissociates ozone to pure oxygen. That would be a statistical result rather than absolute. That is want I want to share here without interfering with the HN discussion on disinfection.
[1] Ozone: https://www.cdc.gov/niosh/idlh/10028156.html
I have no connection to any of the organizations mentioned.