ng/L

nanogram per liter

Concentration

The nanogram per litre is 10⁻¹⁰ percent, one part per trillion in dilute water. It is the reporting unit for PFAS, pharmaceuticals and endocrine disruptors in water supplies; the 2024 US drinking water limits for PFOA and PFOS are 4 ng/L.

Watch out: At nanogram-per-litre levels the sampling equipment is a bigger problem than the analysis. PFAS in particular are found in tubing, container caps and even in some laboratory water, so a positive result at this level means nothing without matching field and laboratory blanks.

1 ng/L 1.0000000e-10 %