Environment
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ship which has a sulphur test result indicating potential non-compliance may lodge a ‘Note of Protest’ (NOP) with its flag state with a copy of the bunker delivery note (BDN), and the analysis report. The vast majority of such sulphur NOPs, historically over 80%, tends to be for fuels with sulphur test results falling within the 95% confidence limits. It is important to note that such a test result does not prove that the fuel supplied was non-compliant, it is merely indicative of a potential sulphur limit breach, but it isn’t clear if that is understood by the relevant authorities in flag and coastal states. In 2014, experts at CIMAC published a paper illustrating that the Appendix VI to MARPOL approach not only fails in the task of measuring the ‘true value’, but by not adhering to the ISO 4259 process for assessing test results it can also result in a fuel oil being found noncompliant, in accordance with Annex VI when both the supplier’s and receiver’s test results meet the specification limit, where that is defined as a MARPOL Annex VI Regulation 14 sulphur value. How, I hear you say. Let’s say you test a fuel which has a “true value” of 0.50% sulphur. If you tested it 100 times, the number of test results falling either side of 0.50%, but within the 95% confidence margin, should be the same. But it is quite possible that out of the first four, two tested at exactly 0.50% and two tested slightly above, while the remaining 96 tests gave an even distribution and a final average of exactly 0.50% sulphur. But if you looked only at the first four test results, your average would be slightly above 0.50% and it would fail the MARPOL verification procedure. The devil really is in the detail on this issue. The CIMAC paper recommended that the sulphur verification procedure in MARPOL Annex VI should be aligned with ISO 4259 to provide a more uniform, robust and reliable system. In 2015, building on the arguments in the CIMAC paper, IBIA proposed this to MEPC 68. It was, however resisted because of suspicion among member states that bunker suppliers would then be tempted to blend either exactly to the sulphur limit
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or even marginally above because of the “error margin” afforded under the 95% confidence limit. Correct application of ISO 4259 The CIMAC paper, and IBIA’s proposal to MEPC 68 in 2015, explained that there is an important distinction in the application of the testing precision boundary in commercial application using ISO 4259, with different approaches for the supplier and for the recipient as to whether a specification limit has been met. Applying ISO 4259, the recipient (ship) can only consider that a maximum specified limit value has been exceeded if their test result exceeds the limit plus 0.59R, or 95% confidence. For the supplier, with a single test result, the approach is that in the case of a maximum specification limit, the specification limit has been met, with 95% confidence, if the test result is less than or equal to the specification limit minus 0.59R. What this means is that if a supplier’s retained sample is tested, that test result must not exceed a maximum limit at all. They do not have the ‘luxury’ of applying the limit plus 0.59R. If a supplier is using a blend target equal to the specified limit, there would be as many test results above the specified limit as below (50/50 chance), meaning that, for the supplier to be 95% confident that they do not exceed the limit, the supplier should blend to the limit minus 0.59R. These principles should suffice to ensure suppliers are careful not to blend too close to the sulphur limit, but in a competitive market place some may be tempted to blend to the actual limit rather than the limit minus 0.59R. The question is: what harm would that do? As long as the sulphur test results fall within the 95% confidence limits, the regulation’s intended benefits of reducing harmful sulphur emissions are achieved. By and large, authorities in reality do not seek to crack down hard on marginal infractions, though practices with regards to penalising sulphur limit exceedances will vary between countries, as we have already seen in countries checking ships for ECA compliance.
IBIA efforts at IMO With an eye on the potential explosion of sulphur disputes that may materialise in 2020, what should we do? If IBIA were to put in a new proposal for the IMO to adopt ISO 4259, there is a risk of scoring an own goal because many would simply dismiss it as a repeat of the attempt at MEPC 68 in 2015 which was not sufficiently supported. So for now, IBIA is working on educating all parties to build a better understanding of these issues, playing the long game. As part of this effort, on January 17 this year, IBIA put on a lunchtime presentation in the main hall at IMO’s London headquarters for delegations attending the fourth session of the Sub-Committee on Pollution Prevention and Response (PPR 4). IBIA took this opportunity raise awareness of the current differences between commercial and statutory approaches and the problems resulting from it. IBIA invited Tim Wilson, Principal Specialist on fuels at Lloyd’s Register, to do the presentation and worked closely with him on the content. Among the key messages Wilson put across at PPR 4 was that sulphur inspection authorities need to be mindful of the current differences between commercial and statutory approaches, and to understand that all test methods use 4259 to define the confidence testing boundary. He also suggested that NOPs should not include reports of ships’ single test results where the sulphur limit exceedance is within 95% confidence limits. This only causes anxiety for shipowners about potentially being non-compliant but gives them no commercial ‘off-spec’ case against the supplier. The key point to understand, Wilson said, is that inconsistency in testing procedures could result in wrong indictments of ships and/ or suppliers. By raising awareness of how the discrepancies between the regulation and commercial practices are causing a lot of pain for no gain, IBIA hopes this will help member states understand the issues and take a common sense approach when it comes to enforcement of MARPOL sulphur limits.
The only official magazine of IBIA, World Bunkering sUMMER 2017