A closure system includes an inner cap including a plurality of driving structures disposed proximate a periphery of a top surface of the inner cap, a child proof element separated from the inner cap configured to be assembled with the inner cap to form a child proof cap, and a key having a plurality of projections. The child proof element when assembled with the inner cap in a child proof mode is configured to require the plurality of projections of the key to engage at least a portion of the plurality of driving structures of the inner cap to remove the assembled child proof cap when the child proof cap is installed on the container.