How much naphthalene is harmful for human?
The NIOSH recommended time weighted average (TWA) exposure limit for naphthalene is under 50mg/m³ or 10 ppm, above which will cause significant harm to humans.
But how much is that r e a l l y ? Like give some examples of how one would surpase that exposure limit.
According to the EPA, Naphthalene's minimum odor threshold is 0.084 ppm for humans, far below the danger threshold. If you are in an area where the smell is noticeable (but not overpowering), you are not in immediate danger, though you should still leave the area as soon as reasonably possible.