Abstract: The safety closure includes an outer closure member having cylindrical interior walls, and an inner cylinder. The inner cylinder is nested within the interior walls of the outer closure member, and permits normally free rotation of the outer closure member relative to the inner cylinder. Complementary screw threads connect the inner cylinder to a mouth of the container, and cooperate with the outer closure member to lock the safety closure onto the container. A key is permanently secured to the safety closure for unlocking engagement of the complementary screw threads. The key is manipulated by a user to prevent the normally free rotation of the outer closure member relative to the inner cylinder, thus permitting the safety closure to be removed from the container.