MARPOL Regulation on Fuel Oil Quality

1. Fuel oil combustion purposes delivered to and used onboard ships to which this Annex applies shall meet the following requirements:
1. Except as provided in Paragraph 2 of this regulation:
1. The fuel oil shall be blends of hydrocarbons derived from petroleum refining. This shall not preclude the incorporation of small amounts of additives intended to improve some aspects of performance.
2. The Fuel oil shall be free from an inorganic acid
3. The Fuel oil shall not include any added substances or chemical wastes that: 
1. Jeopardizes the safety of ships or adversely affects the performance of the machinery; or
2. In harmful to Personnel; or
3. Contributes overall to additional Air Pollution.
2. Fuel oil for combustion purposes derived by methods other than petroleum refining shall not:
1. Exceed the applicable sulphur content set forth in Regulation 14 of this Annex.
2. Causes an engine to exceed the applicable NOx emission limit set forth in Regulation 14 of this Annex.
3. Contain an inorganic acid; or
4. Jeopardizes the safety of ships or adversely affects the performance of the machinery; or
5. In harmful to Personnel; or
6. Contributes overall to additional Air Pollution.
3. This Regulation does not apply to coal in its solid form or nuclear Fuels. Regulations do not apply to gas fuels such as liquified natural gas, compressed natural gas or liquified petroleum gas. The sulphur content of gas fuels delivered to a ship specifically for combustion purposes on board that ship shall be documented by the supplier.
4. For each ship, details of fuel oil for combustion purposes delivered to and used onboard shall be recorded by means of a Bunker Delivery Note which shall contain at least the information specified in Appendix V of this Annex.
5. The Buker Delivery Note shall be kept on board the ship in such a place as to be readily available for inspection at all reasonable times. It shall be retained for a period of three years after the fuel oil has been delivered on board.
6. The competent authority of a Party may inspect the Bunker Delivery Notes on board any ship to which this Annex applies while the ship is in its port or the offshore terminal may make a copy of each Delivery note and may require the master or person in charge of the ship to certify that each copy is a true copy of such bunker delivery note. The competent authority may also verify the contents of each note through consultations with the port where the note was issued. 
7. The inspection of Bunker Delivery Note and the taking of certified copies by the competent authority under this Paragraph shall be performed as expeditiously as possible without causing the ship to be unduly delayed.
8. The Bunker Delivery Note shall be accompanied by a representative sample of the fuel oil delivered taking into account guidelines developed by the Organization.
9. The sample is to be sealed and signed by the supplier's representative and the master or officer in charge of the bunker operation on completion of bunkering operations and retained under the ship's control until the fuel oil is substantially consumed, but in any case for a period of not less than 12 months from the time of delivery. 
10. If an Administration requires the representative sample to be analysed, it shall be done in accordance with the verification procedures to determine whether the fuel oil meets the requirements of this Annex.
11. Parties undertake to ensure those appropriate authorities designated by them:
1. Maintain a register of local suppliers of fuel oil.
2. Require local suppliers to provide the Bunker Delivery note and sample as required by this regulation, certified by the fuel oil supplier that the fuel oil meets the requirements of Regulation 14 and Regulation 18 of this Annex.
3. Require local suppliers to retain a copy of the Bunker Delivery Note for at least three years for inspection and verification by the Port state as necessary.
4. Take action as appropriate against fuel oil suppliers that have been found to deliver fuel oil that does not comply with that stated on Bunker Delivery Note.
5. Inform the Administration of any ship receiving fuel oil found to be non-compliant with the requirements of Regulation 14 (or) Regulation 18 of this Annex.
6. Inform the Organization for transmission to Parties and the Member States of the Organization of all cases where fuel oil suppliers have failed to meet the requirements specified in Regulation 14 (or) Regulation 18 of this Annex.
12. In connection with Port state inspections carried out by Parties, the Parties further undertake to:
1. Inform the Party or non-Party under whose jurisdiction a Bunker Delivery Note was issued of cases of delivery of non-compliant fuel oil, giving all relevant information; and
2. Ensure that remedial action as appropriate is taken to bring non-compliant fuel oil discovered into compliance.  
13. For Every Ship of 400 Gross Tonnage and above on scheduled services with frequent and regular port calls, an Administration may decide after application and consultation with affected States that compliance with this Regulation may be documented in an alternative manner which gives similar certainty of compliance with Regulation 14 (or) Regulation 18 of this Annex.  

Reference: IMO Publications & Documents - International Conventions - MARPOL - Annex VI