When handed over for carriage, uncleaned empty tanks shall be filled with a protective agent fulfilling one of the following measures:

+-------------+----------------+-------------------------------------------+
| Protective  | Degree of fil- | Additional requirements for carriage at   |
|   agent     | ling of water  |         low ambient temperatures          |
+-------------+----------------+-------------------------------------------+
| Nitrogen a) |       --       |                                           |
+-------------+----------------+-------------------------------------------+
| Water and   |       --       |                                           |
| nitrogen a) |                |                                           |
+-------------+----------------+-------------------------------------------+
| Water       | not less than  | The water shall contain sufficient anti-  |
|             | 96 % and not   | freeze agent to prevent it from freezing. |
|             | more than 98 % | The anti-freeze agent shall be free from  |
|             |                | corrosive action and not liable to react  |
|             |                | with the substance.                       |
+-------------+----------------+-------------------------------------------+

__________
a) The tank shall be filled with nitrogen in such a way that, even after cooling, the pressure at no time falls below atmospheric pressure. The tank shall be closed in such a way that no leakage of gas occurs.