Biofuels use under MARPOL Annex VI


Published: 1 September 2022

Credit to: petrmalinak /

We are receiving an increased number of technical inquiries both on P&I and Hull related to the use of marine biofuel grades available in the market, either as an alternative fuel or for main engine testing for future use.

The major issue we want to highlight is the requirement under MARPOL regulation which states that: a fuel oil for combustion purposes derived by methods other than petroleum refining shall not cause an engine to exceed the applicable NOx emission limit set forth in paragraphs 3,4,5.11 and 7.4 of regulation 13.

Skuld recommends its members and clients who are now using, or intending to use, biofuels to always obtain confirmation from their Classification Society or Flag State for an exemption to use such fuels and also to ask the Flag State for a determination of the NOx emissions in accordance with the relevant provisions of the NOx Technical Code 2008. Also, if the vessel has an existing Flag State approval for the use of restricted biofuel blends, to obtain confirmation that higher ratio of biofuels may be used without the need for further NOx emission trials.

In June 2022, MEPC 78 approved as per the enclosed circular MEPC.1/Circ.795/Rev.6 a Unified Interpretation to MARPOL ANNEX VI paragraph 13 in relation to the use of biofuels. It is important to note that biofuel blends of 30% by volume or less should simply be considered as conventional petroleum derivative fuels. For non-petroleum derived fuels other than biofuels, the provisions of this regulation apply as per regulation For biofuels and biofuel blends of more than 30% by volume, if NOx critical components and operational values are required by the engine's technical file, then NOx emission trials should not be required.

In view of the above, Skuld would like to advise its members to always contact their respective Classification Society or their Flag State for clarification and guidance.