Equivalency arrangements for the carriage of Styrene Monomer
- The Maritime Safety Committee, at its sixty-ninth session, and the Marine Environment Protection Committee, at its forty-second session, agreed that, in accordance with the provisions of paragraph 1.4 of the IBC Code, the carriage of styrene monomer under the conditions indicated below, should be considered as equivalent to those identified in paragraph 15.3.5 of the IBC Code.
- Contracting Governments to the 1974 SOLAS Convention and Parties to MARPOL 73/78 are therefore advised that they may transport styrene monomer in a chemical tanker with cargo tanks over 3,000 m3 fitted with an IGS (Inert Gas System), provided that the oxygen content inside those tanks is maintained between 2% and 8% and that the following operational measures are observed:
- upon completion of loading and taking of product samples, the vapour space is checked to ensure that the oxygen level is within acceptable limits (2% to 8%). Although levels as low as 2% are adequate, levels of oxygen between 6% and 8% are preferred;
- during the voyage, the vapour space oxygen content is monitored and recorded at least
twice per day, at least 8 hours apart; and
- temperature and pressure readings of the cargo tanks are monitored and recorded at least twice per day, at least 8 hours apart.