UNIT CONVERSION

Media Units Adjustment
Water mg/l (Standard) x 1
  PPM x 1
  µg/l ÷ 1,000
  PPB ÷ 1,000
Soil mg/kg (Standard) x 1
  µg/mg x 1
  µg/kg ÷ 1,000
  PPM x 1
  PPB ÷ 1,000
Air mg/m3 (Standard) x 1
  µg/m3 ÷ 1,000
  PPM x (molecular wt.) ÷ 24.45
  PPB x (molecular wt.) ÷ 24,450
EXAMPLES:

Water: 17 µg/l = 17 ÷ 1,000 = 0.017 mg/l

Soil: 1,350 µg/kg = 1,350 ÷ 1,000 = 1.35 mg/kg

Air: 0.075 PPM (of benzene) = 0.075 x 78.11 ÷ 24.45 = 0.24 mg/m3

  Where: the molecular weight of benzene = 78.11 g/mole

  Source of molecular weight information: http://risk.lsd.ornl.gov/cgi-bin/tox/TOX_select?select=nrad  

  1. Select "Chemical-Specific Factors"

  2.Then "Molecular Weight (MW)" and the desired chemical(s))