Abstract: A safety closure comprises a cap having a pair of locking lugs which engage complimentarily disposed camming surfaces on the associated container and a plug or valve style liner disposed within the cap. The liner includes a generally planar disk having a hollow cylindrical plug defining an outer surface having a compound taper and a conical projection spaced concentrically about said cylindrical plug. The liner extends into the finish of the container and seals it during axial translation of the closure corresponding to 180.degree. or less rotation thereof. The liner, due to its simplicity, may be fabricated of material which exhibits resistance to the product within the container but which would otherwise be unsuitable or difficult to mold into the cap.