Particulate Matter PM2.5

Particulate matter (PM) are inhalable and respirable particles composed of sulphate, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water. fine particles less than 2.5 microns (PM2.5) pose the greatest risks to health, as they are capable of penetrating peoples’ lungs and entering their bloodstream. Sources of PM include combustion engines (both diesel and petrol), solid-fuel (coal, lignite, heavy oil and biomass) combustion for energy production in households and industry, as well as other industrial activities (building, mining, manufacture of cement, ceramic and bricks, and smelting).


Particulate matter 2.5

Time-weighted average

35 - 15 µg/Nm3 (ppm)

Averaging time

24 hour - Annual

Time –weighted average Averaging Time Number of allowable exceedances
35 µg/m3 24-hour 24 times per annum
15 µg/m3 annually None
Number of allowable exceedances

24 times per annum4 - N/A