Edwin Pawlowski wrote:

"Mr Fixit eh" wrote in

If your filter has not been independently tested to capture 99.9% of
particles between 0.2 and 3.0 micron, it will be missing most of the
particles that are dangerous to your health.

What if my filter catches the 99.9% of particles but has not been
independently tested. Will it then harm my lungs?

Only if you're not using the charcoal filter to catch the acetone
fumes...