The enantiomer ratio (ER) is currently the standarddescriptor of enantiomeric (chiral) signatures for environmental samples. In this paper, we argue for the adoptionof the enantiomer fraction (EF) as the standard descriptorby showing drawbacks to the use of ER. The enantiomerfraction is superior because it provides a more meaningfulrepresentation of graphical data and is more easilyemployed in mathematical fate expressions. Several usefulexpressions are presented that allow EF to be used fortracking and apportioning chemical movement betweenenvironmental compartments and for investigating microbialdegradation processes.