Question 1

Are PPM and mg/L always the same?

Accepted Answer

They are equivalent for dilute aqueous solutions. However, if the density of the solution is significantly different from water, the concentration in mg/L must be adjusted by the density of the liquid.

Question 2

Why use one unit over the other?

Accepted Answer

PPM is a dimensionless ratio often used for general reporting, while mg/L is a specific mass-per-volume unit preferred in laboratory and scientific analysis.

Ppm To Mgl Converter