Bunker Fuel Standard Under Review

The international standard on the quality of marine fuels is under review following a recent announcement at the 35th International Bunker Conference in Copenhagen. The expected changes have been reported but not yet finalised. The standard, ISO 8217, specifies the requirements for petroleum fuels for use in marine applications.

Although internationally recognised, ISO 8217 is not a strict mandatory quality standard. It is however a commercial specification and it is widely used in the shipping industry, referenced in almost all bunker purchasing contracts and time charter parties.

ISO 8217 was last updated in 2012 where the measurement of hydrogen sulphide was added to the specification for distillate fuels. Prior to this, the update in 2010 introduced a number of changes, notably the reduction in allowable concentrations of aluminium and silicon, more commonly known as cat fines, in residual (heavy) fuels.

Interestingly, it is the 2005 edition of ISO 8217 that has remained the most commonly used. Back in 2013, DNV Petroleum Services reported that only around 11% of bunker contracts specified the 2010 or 2012 versions. According to market analysts Platts, suppliers guaranteeing 2010/2012 specification fuels can command a premium.

The most notable changes expected in the new edition concern the potential addition of fatty acid methyl ester (FAME) biodiesel blends in distillate fuels.

In particular, there will be a new set of distillate grades introduced: DFA, DFB and DFZ. These additional grades essentially correspond to the existing distillate grades of DMA, DMB and DMZ but they allow up to 7% FAME content.

FAME has traditionally been considered a contaminant in marine fuels and was previously only allowed in de minimis levels. ISO 8217:2012 defined this as a maximum of 0.1%, but the new edition raises these levels to 0.5% for the distillate grades DMA, DMB and DMZ. Excepted is DMX which must remain free from any FAME content. This increase of FAME content up to 0.5% has caused concern from some parts of the industry. Some parties have voiced concern that this constitutes an acceptance that FAME levels will now be tolerated rather than the original intention of making an allowance for the trace contamination of fuel.

The limits for the standard parameters for residual grade fuels are not expected to change. Therefore the commonly used residual fuels, RMG 180 and RMG 380 should be unaffected. The sulphur limits for some distillate fuel grades will be reduced. DMB will change from 2.00% to 1.50% and DMA and DMZ will be reduced from 1.50% to 1.00%. The sulphur limit of DMX will remain unchanged at 1.00%.

It is very important to note that the sulphur limits stated in any edition of ISO 8217, whether old or new, does not necessarily correspond with the limits imposed by international, regional or domestic environmental legislation. For example, when ordering fuel to comply with the MARPOL Annex VI emission control areas, it is essential that the 0.1% maximum sulphur content is explicitly specified in the contract in addition to the requirement to comply with ISO 8217.

Finally, it is understood that the recently introduced ‘hybrid’ fuels have not been addressed in the revisions. A number of the major producers developed low sulphur blends for the marine market to meet the lowering of sulphur limits in emission control areas last year. These hybrids offered an alternative to traditional distillates but it was found that a number of them did not sit conveniently within the existing grades listed in ISO 8217. If buying hybrid fuels that sit outside the recognised grades, then the buyer and supplier should consider agreeing on fuel characteristics based on an appropriate and relevant ISO 8217 grade.