An electrophotographic photoconductor including a photoconductive layer which is formed overlying an electroconductive substrate and which includes at least a charge transporting polymer material, wherein the photoconductive layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.-2 .multidot.24 h.sup.-1. The photoconductive layer may be a functionally separated photoconductive layer including a charge generating layer and a charge transporting layer which is formed overlying the charge generating layer and which includes the charge transporting polymer material, wherein the charge transporting layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.2 .multidot.24 h.sup.-1.