mg/m³

milligram per cubic meter

Densityexact by definition

The milligram per cubic metre is exactly 10⁻⁶ kilograms per cubic metre. It is the unit of air quality and industrial hygiene: particulate matter, welding fume and solvent vapour exposure limits are all expressed this way.

Watch out: Occupational limits appear both in mg/m³ and in ppm by volume, and converting between them needs the molar mass of the substance and the temperature. There is no universal factor, and using someone else's is how a limit gets misapplied.

1 mg/m³ 0.000001 kg/m³