Tamper evident closure

A system for providing an indication of the opening of a closure, said closure mounted on a container, said system comprising:

• a. a first portion of said closure, wherein said first portion is a removable top, said first portion further comprising:
• i. an inner part and an outer part, wherein said inner part comprises a disk-shaped top plate with a cylindrical skirt depending from the periphery of said top plate and wherein said cylindrical skirt has a first set of screw threads for engaging a first set of corresponding threads on said outer part and the inner surface of said cylindrical skirt has a second set of screw threads for engaging a second set of corresponding threads on said container;
• and
• ii. a ratchet arrangement for locking said inner part and said outer part;
• and
• b. a second portion of said closure, said second portion connected to said container, wherein said outer part is movable relative to said inner part from a first position in which said outer part is immediately adjacent said second portion, to a second position in which there is an empty, unobstructed gap therebetween and around the entire periphery of said outer part and said second portion, wherein in said second position said first portion is removable and said inner part and said outer part are constructed and arranged to be irreversibly locked in said second position, so that said outer part cannot be moved back to said first position to close said gap when said first portion is replaced.