1 part per million fluoride is:
ppm (or ppmm) is used to measure the concentration of a contaminant in soils and sediments. In that case, 1 ppm equals 1 mg of substance per liter of solid (mg/liter).
1 mg in 10 L of water
1 mg in 1 L of water
10 mg in 1 L of water
100 mg in 10 L of water