| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| AUSTRIA | Signature | 03/06/1954 | |
| BELGIUM | Signature | 28/11/1952 | |
| DENMARK | Signature | 28/11/1952 | |
| FRANCE | Signature | 28/11/1952 | |
| ITALY | Signature | 28/11/1952 | |
| ITALY | Ratification | 07/07/1955 | |
| NETHERLANDS THE | Signature | 28/11/1952 | |
| NORWAY | Signature | 10/02/1954 | |
| SWEDEN | Signature | 28/11/1952 | |
| SWITZERLAND | Signature | 28/11/1952 | |
| UNITED KINGDOM |