A foam injection plug assembly for use in a refrigeration appliance, comprising - an inner case which forms a refrigeration compartment and an outer case which encloses at least partly the inner case, wherein the outer case has an aperture which defines a passage for injecting liquid foam material into the intermediate region between the inner case and the outer case, - a pivotable lid which is configured to pivotably move within the intermediate region between a first position where the aperture is leak-tightly closed and a second position where the aperture is opened, - a frame which is attachable to the outer case around the aperture and to which the pivotable lid is hinged, characterized by - a spring element which is attached to the frame and configured to abut against the rear surface of the lid, which is averted from the foam injection direction so as to bias the lid to the first position, - the frame comprising an inner cover which has a first opening, wherein the inner cover is configured to leak-tightly abut against the inner surface of the outer case such that the first opening fluidly communicates with the aperture, - the frame further comprising an outer cover which has a second opening, wherein the outer cover is configured to leak-tightly abut against the outer surface of the outer case such that the second opening fluidly communicates with the aperture, wherein the first opening, the aperture and the second opening define the passage for injecting the liquid foam material into the intermediate region, - the outer case having one or more than one cut-out, the inner cover having one or more than one connector and the outer cover having one or more than one counterpart connector for releasably engaging with the corresponding connector through the corresponding cut-out. - an inner case which forms a refrigeration compartment and an outer case which encloses at least partly the inner case, wherein the outer case has an aperture which defines a passage for injecting liquid foam material into the intermediate region between the inner case and the outer case, - a pivotable lid which is configured to pivotably move within the intermediate region between a first position where the aperture is leak-tightly closed and a second position where the aperture is opened, - a frame which is attachable to the outer case around the aperture and to which the pivotable lid is hinged, characterized by - a spring element which is attached to the frame and configured to abut against the rear surface of the lid, which is averted from the foam injection direction so as to bias the lid to the first position, - the frame comprising an inner cover which has a first opening, wherein the inner cover is configured to leak-tightly abut against the inner surface of the outer case such that the first opening fluidly communicates with the aperture, - the frame further comprising an outer cover which has a second opening, wherein the outer cover is configured to leak-tightly abut against the outer surface of the outer case such that the second opening fluidly communicates with the aperture, wherein the first opening, the aperture and the second opening define the passage for injecting the liquid foam material into the intermediate region, - the outer case having one or more than one cut-out, the inner cover having one or more than one connector and the outer cover having one or more than one counterpart connector for releasably engaging with the corresponding connector through the corresponding cut-out.