Epoxidized fatty acid alkyl ester and methods for making epoxidized fatty acid alkyl ester. The epoxidized fatty acid alkyl ester is prepared from a fatty acid alkyl ester starting material comprising at least one of mono-unsaturated and di-unsaturated fatty acid alkyl ester molecules in a combined amount of at least 85 weight percent. Such epoxidized fatty acid alkyl esters can be employed in plasticizer compositions, either alone or in combination with other plasticizers, such as epoxidized natural oils. Such plasticizers in turn may be used in the formation of polymeric compositions.