Closure system and container having a closure system

A closure system for a container (1) of paste or liquid media, which container is realized as a tube or bottle and includes an output neck (1a), said closure system comprising

• an applicator which is connectable to the output neck (1a) and includes a channel with a container-side inlet opening (15) and at least one through-opening (17a, 17b),
• a valve with a valve cover, the at least one through-opening leading to a chamber (37) which is delimited on an outside by the valve cover (9), said valve cover (9) comprises an outlet opening (11) with a valve seat, and a closing member (7) of the valve is fastened on the applicator and is movable between an open position, in which a pressure of the paste or liquid media in the chamber acting on a chamber side surface of the closing member (7) elastically deforms the closing member and releases the outlet opening (11), and a closing position, in which the closing member is pressed from an inside surface of the chamber (37) against the valve seat by a restoring force of a resiliently deformable restoring element and, as a result, closes the outlet opening (11), and
• a mechanical blocking element (19), a relative position of which with respect to the closing member (7) is modifiable between a releasing position and a blocking position, wherein the blocking element (19) prevents the valve from opening in the blocking position, but not in the releasing position.