Vial cap

In combination, a cap and overseal on a vial having a neck portion surrounding an open end portion thereof, a pair of axially spaced radially outwardly extending annular beads integral with the outer wall surface of said vial neck, said cap having a skirt portion, a pair of axially spaced radially inwardly extending annular ribs integral with the inner wall of said skirt portion, said skirt portion being press fit onto the neck portion of the vial wherein each annular rib extends inwardly against the lower surface of a respective bead, a transversely extending wall portion integral with the upper end portion of the skirt, a self-sealing disc mounted on the upper edge portion of the neck between the open end of the vial and the transversely extending wall portion, a central opening formed in the transversely extending wall of the cap, whereby a hypodermic needle may be inserted through the sealing disc to remove contents from the vial, a lid, and a hinge connected between the lid and the upper end portion of the cap skirt, whereby the lid can be pivoted from an open position to a closed position over the central opening in the transverse wall to thereby cover the sealing disc to prevent the accumulation of atmospheric debris thereon during storage.