Advise from a Doctor family member in USA
“It’s not only that the devices are ineffective and maybe lull people into a false sense of security, but in some cases they’re actually harmful.”
Watch out, in particular, for machines that can generate ozone. Ozone is a pollutant that can interact with a lot of different products in your home and create harmful chemicals to breathe in. “It reacts with carpets and skin oil and all kinds of things inside of buildings,” “forming all kinds of harmful byproducts, ultra-fine particles, formaldehyde, all kinds of other things that we would worry about indoors.”
So stick with HEPA or MERV-13+ rated filters. Or just open windows.
BIS is India should be telling us this. But instead its asleep. more