| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| BELGIUM | Accession | 22/04/1955 | |
| CANADA | Accession | 03/05/1955 | |
| DENMARK | Accession | 04/05/1955 | |
| FRANCE | Signature | 23/10/1954 | |
| FRANCE | Ratification | 05/05/1955 | |
| GERMANY FEDERAL REPUBLIC | Signature | 23/10/1954 | |
| GERMANY FEDERAL REPUBLIC | Ratification | 20/04/1955 | |
| LUXEMBOURG | Accession | 04/05/1955 | |
| NETHERLANDS THE | Accession | 30/04/1955 | |
| UNITED KINGDOM | Signature | 23/10/1954 | |
| UNITED KINGDOM | Ratification | 05/05/1955 | |
| UNITED STATES OF AMERICA | Signature | 23/10/1954 | |
| UNITED STATES OF AMERICA | Ratification | 20/04/1955 |