Look up: Parts Per Million

1. Parts per million
   Proportion of toxicant present in relation to that of plant material on which it has been deposited. (Usually applied in connection with edible portion of crops).
   Found on http://www.encyclo.co.uk/visitor-contrib
   
   
2. Parts Per Million
   Units of measurement for volumetric concentration of airborne contaminant.
   Found on http://www.encyclo.co.uk/local/20474
   
   
3. parts per million
   (ppm) Concentration expressed as parts of solute per million parts of solution. Usually refers to parts per million by mass. For example, a 10 ppm NaCl solution can be written as: 10 mg NaCl/kg solution, 10 µg NaCl/g solution, 10 ng NaCl/mg solution. In very dilute aqueous solutions, ppm is appr...
   Found on http://antoine.frostburg.edu/chem/senese
   
   
4. parts per million
   A measure of proportion by weight, equivalent to one unit weight of a material per million (10sup>6) unit weights of compound. One part per million is equivalent to l mg/g
   Found on http://www.encyclo.co.uk/local/20742