IMO seeking to amend sulphur testing and sampling regulation


The International Maritime Organization (IMO) will be discussing changes to the MARPOL Annex VI regulations on how Port State Control (PSC) can draw fuel oil samples on board, when meeting at the 75 session of the Marine Environment Protection Committee (MEPC 75) on 16 to 20 November 2020. Some of the new suggestions are a cause for concern, BIMCO believes.

While shipowners have been focused on the 2020 sulphur regulation which entered into force on 1 January 2020 due to safety concerns, IMO members states have had their eyes on the procedures that control whether ships are carrying low-sulphur fuel oil in accordance with the new regulations.

In connection with the amendments to MARPOL Annex VI a few definitions will come in handy:

  • In-use sample, defined as the sample of fuel oil in use on a ship. It can for example be drawn from the fuel oil line between the service tank and an auxiliary engine.
  • On board sample, defined as the sample of fuel oil intended to be used or carried for use on board a ship. It is drawn directly or indirectly from fuel oil tanks.

According to the new regulation, authorities including Port State Control are thus given explicit authority to draw oil samples from the ship’s fuel oil tanks.

BIMCO is concerned with the suggested procedure for ‘On board sampling’ to be used for determining if the ship is in compliance with the sulphur regulation, since the only truly homogenous and representative fuel oil sample is the MARPOL sample (MARPOL delivered sample). The new suggestion could cause confusion and uncertainty between the ship, bunker supplier, time charter and other stakeholders, especially if the testing results turn out to be different, BIMCO believes.

Direct samples drawn through the sounding pipe or the manhole cannot in BIMCO’s view be considered homogenous and representative for the sulphur content in the fuel oil tank. This is recognised (but also disregarded) in the circular on early application of the verification procedures for a MARPOL Annex VI fuel oil sample (MEPC.1/Circ.882 ):

“The in-use or on board fuel oil sample, as appropriate, shall be used to verify the sulphur content of the fuel oil as represented by that sample of fuel oil at the point of sampling.”

This means that a fuel oil sample drawn by PSC is only representative of the fuel oil at the level or point of suction, but not representative of the fuel oil in the tank.

Indirect samples drawn by using the fuel oil transfer pump, cannot be used either, since the sample is not homogenous and representative of the sulphur content in the tank. Since the transfer pump’s suction is placed in the bottom of the fuel tank, BIMCO fears that such samples would show wrong results even if the sulphur content of the fuel oil is actually compliant.

This leads to the fact that the only fuel sample truly homogenous and representative of the sulphur content that is available today, is the MARPOL sample because it is drawn over the entire bunker operation.

Safety concerns in case of direct sampling from fuel oil tanks

A normal fuel oil tank only has two openings, the manhole, for inspection when the tank is empty, and the sounding pipe. Fuel oil tanks on existing ships are not constructed with designated sampling points.

The manhole should never be opened while there is fuel oil inside the tank. Fuel oils are stored at high temperatures and it is consequently unsafe for the people taking the sample.

The MARPOL (delivered) sample is still essential

The statutory fuel verification procedure for MARPOL Annex VI fuel oil samples is being updated to include the new fuel oil samples and making the text of the circular on early application of the verification procedures for a MARPOL Annex VI fuel oil sample mandatory. 

More information can be found here interpretation of the discord between MARPOL and commercial fuel samples.

Compared to the current verification procedure, MARPOL (delivered) samples will in the future be tested without taking the Reproducibility (R) of the test method into consideration. This means there will be no test margin and thus, the test result of a MARPOL sample (average of two tests by the same laboratory) must not exceed 0.50% m/m sulphur.

For ‘In-use’ and ‘On board’ samples, the Reproducibility (R) of the test method, in accordance with ISO 4259-2:2017, should be taken into consideration when assessing whether the test result is acceptable or not. This means that the test result, from the fuel oil samples drawn by PSC, shall be considered acceptable if the sulphur content does not exceed 0.53%.

This small but essential difference between the verification procedure for MARPOL samples and samples drawn by PSC was agreed by IMO deliberately. The difference is intended to ensure that ships are not unfairly penalised for marginal exceedances due to factors outside the ship’s control.   Time will show if this is sufficient to avoid that different conclusions are drawn from the different types of samples.

In the end we should not forget that it is still the responsibility of the supplier to deliver fuel oil which is compliant with the statutory sulphur content limits i.e. 0.50% or 0.10% m/m.

Christian Baekmark Schiolborg
in Copenhagen, DK


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VPS Bunker Alerts

Veritas Petroleum Services (VPS) publish regular Bunker Alerts based entirely on fuel samples and have kindly permitted BIMCO’s Members to access this information.

The Bunker Alerts are not intended to be an evaluation of overall bunker quality in the port or area concerned, but usually highlight a specific parameter within the fuel which has raised a quality issue.

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