UNIT 3

CONCENTRATION CONVERSION CALCULATION EXAMPLES

HPEO 408 Occupational Health Hazards

ppm ↔ mg/m3 CONVERSIONS

Where:

MW = molecular weight of substance in g/mol

24.45 = molar volume of air in liters at normal temperature and pressure (NTP)

NTP = Temperature (25oC)Pressure (1 atm / 760 mm Hg)

NOTE: if not NTP conditions molar volume may require adjustment

EXAMPLE 1

EXAMPLE 2