| Contracting Parties/Signatories | Signature | Instrument | In Force | Details |
|---|---|---|---|---|
| Austria | June 1, 1951 | Ratification : June 12, 1953 | July 12, 1953 | |
| France | June 1, 1951 | Ratification : May 20, 1952 | July 12, 1953 | |
| Italy | June 1, 1951 | Ratification : March 1, 1954 | March 31, 1954 | |
| Netherlands (Kingdom of the) | June 1, 1951 | Ratification : October 29, 1953 | November 28, 1953 | |
| Switzerland | June 1, 1951 | Ratification : June 5, 1953 | July 12, 1953 |