Question

The EPA (Environmental Protection Agency) currently limits the concentration of fluoride in
drinking water to no more than 4.0 mg per liter of water. What is this concentration in parts per million (ppm)?

Answer 1

Solution.

$1 ppm = \frac{1 mg}{L}$

$\frac{4 mg}{L} = 4 ppm$

Answer:

4 ppm