Where:
Wt = Total chlorine or fluorine usage, by weight;
F1 = Fraction of gaseous or liquid flux that is chlorine or fluorine;
W1 = Weight of reactive flux gas injected;
F2 = Fraction of solid reactive chloride flux that is chlorine (e.g., F = 0.75 for magnesium chloride) or fraction of solid reactive fluoride flux that is fluorine (e.g., F = 0.33 for potassium fluoride); and
W2 = Weight of solid reactive flux;
40 C.F.R. §63.1512