> For clarity, 40 ppm (parts per million) is equivalent to 0.004% of the composition.
Lots of things are dangerous even at concentrations measured in PPM. For example, the level of Phosgene that’s “immediately dangerous to life” is 2 ppm: https://www.cdc.gov/niosh/idlh/75445.html.
Maybe the point is that this 20 ppm quickly turns into less based on further dilution. But there’s a lot of analysis required to support the post’s assertions that the author just skips over.
Lots of things are dangerous even at concentrations measured in PPM. For example, the level of Phosgene that’s “immediately dangerous to life” is 2 ppm: https://www.cdc.gov/niosh/idlh/75445.html.
Maybe the point is that this 20 ppm quickly turns into less based on further dilution. But there’s a lot of analysis required to support the post’s assertions that the author just skips over.