SOLAS – Prohibition of Blending and Production Processes During Sea Voyages IMO Resolution MSC.325(90).

27 March 2014 No. 13-028
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Members' attention is drawn to this important new regulation which came into effect on 1 January 2014.

The Resolution addresses concerns that the physical blending of bulk liquid cargoes during the sea voyage for the purpose of creating new product blends may endanger the ship or the marine environment.  The Resolution which incorporates a new mandatory regulation in SOLAS Chapter VI – Carriage of Cargoes is as follows:-



Part A

General provisions

4 The following new regulation 5-2 is added after the existing regulation 5-1:

Regulation 5-2 – Prohibition of the blending of bulk liquid cargoes and production processes during sea voyages

  1. The physical blending of bulk liquid cargoes during sea voyages is prohibited. Physical blending refers to the process whereby the ship's cargo pumps and pipelines are used to internally circulate two or more different cargoes with the intent to achieve a cargo with a new product designation. This prohibition does not preclude the master from undertaking cargo transfers for the safety of the ship or protection of the marine environment.
  2. The prohibition in paragraph 1 does not apply to the blending of products for use in the search and exploitation of seabed mineral resources on board ships used to facilitate such operations.
  3. Any production process on board a ship during sea voyages is prohibited. Production processes refer to any deliberate operation whereby a chemical reaction between a ship's cargo and any other substance or cargo takes place.
  4. The prohibition in paragraph 3 does not apply to the production processes of cargoes for use in the search and exploitation of seabed mineral resources on board ships used to facilitate such operations.[*]

In addition The 2011 Guidelines for the Carriage of Blends of Petroleum Oil and Biofuels state:-

  1. Blending of Petroleum Oil and Biofuel on Board

5.1   Blending on board describes the mixing of two products resulting in one single product (a blended mixture) and reflects only physical mixing as distinct from any chemical processing.  Such mixing operations should only be undertaken whilst the ship is within port limits.

5.2     The physical blending on board of petroleum oil and biofuels during a sea voyage to create new products is prohibited as indicated in MSC-MEPC.2/Circ.8 - Prohibition of blending MARPOL cargoes on board during the sea voyage.

Before undertaking any on-board blending Members should check the position with their Flag State or the local Coastal Authority.

There are ongoing discussions within the industry.  Members should meantime note the following:-

  • "Bulk cargoes" includes liquefied gas and cargoes which are not MARPOL regulated.

  • Blending at an anchorage en route may not be permissible where, for example, there are no facilities for quick response to a spillage. Blending at an anchorage within a port may be permissible.  The local port authority should be consulted;

  • A vessel undertaking this operation is exposed to the risk of quality/shortage claims – clear indemnities should be sought from Charterers/Cargo Interests;

  • All movements of oil cargoes must be recorded in the Oil Record Book (Regulation 20 of Annex I of MARPOL 73/78);

  • Great care to avoid claims must be taken especially if undertaking this operation in U.S. waters. Specialist advice from the Club's local correspondents should always be sought if in doubt;

  • The prohibition of the blending of cargoes does not apply where cargo is recirculated within its cargo tank or through an external heat exchanger during the voyage for the purpose of maintaining cargo homogeneity or temperature control, including when two or more different products have previously been loaded into the same cargo tank within port limits;

  • Load on top and additives such as anti-static and dyes are not included in this regulation providing the chemical composition of the cargo is not changed. A pump maybe used to mix these within the tank, however circulating externally from the tank is not envisaged.


[*] Refer to the Guidelines for the transport and handling of limited amounts of hazardous and noxious liquid substances in bulk in offshore support vessels (resolution A.673(16), as amended)."