ISO Publishes Long Awaited IMO2020 Publicly Available Specification for Marine Fuel

PAS 23263:2019 is now available. Image Credit: ISO

IMO's long awaited Publicly Available Specification (PAS) for IMO2020 grade bunkers has been published by ISO.

PAS 23263:2019 "Considerations for fuel suppliers and users regarding marine fuel quality in view of the implementation of maximum 0,50 % sulfur in 2020" is the product of IMO's ISO 8217 working group.

As has been discussed at length, no revision to the ISO8217 standard for marine fuel is being made ahead of IMO2020 despite the fact the new 0.50% sulfur cap has prompted suppliers to develop a new class of bunker fuels commonly being referred to as VLSFO.

Instead, the PAS describes how the current ISO 8217 standard, and particularly the latest ISO 8217:2017 edition, can be applied to the new fuels.

"It confirms that ISO 8217 specifications still apply to fuels meeting the 0.50% sulphur limit, and provides technical advice on fuel characteristics that might apply to particular fuels for kinematic viscosity, cold flow properties, stability, ignition characteristic and catalyst fines. In addition, it provides information on how to consider compatibility between fuels, including test methods for checking whether fuels are compatible," the International Bunker Industry Association (IBIA) says of the new PAS.

Perhaps one of the most notable aspects of the new IMO2020 grade fuels is that it is already clear that suppliers will produce fuels using many different recipes.

This means VLSFOs are going to exhibit a much wider range of characteristics than the industry's current go to fuel, IFO380, that is typically sold simply against the RMG380 specification.

"Fuel testing agencies have, between them, already tested thousands of samples of VLSFO produced to meet the 0.50% sulphur limit, and have reported considerable variations in viscosity and density. Viscosity in the tested samples is said to typically range from 30 cSt to 380 cSt. A few samples have been below/above that range with lows of 6-7 and highs of up to 500 cSt reported, but these are rare," IBIA explains.

"Density has been seen in a range of 850 to almost 998, with most above 900 kg/m3 which puts them firmly into the Table 2 (RM) specifications."

So while all 0.50% sulfur fuels will need to meet ISO 8217 specifications, some will best be described using DM specs and others one of the RM specs - RMA 10, RMB 30, RME 180 etc.

Indeed, IBIA predicts one consequence of IMO2020 could be an uptick in DMB-grade fuels.

PAS 23263 is available here: https://www.iso.org/standard/75113.html