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Bunker fuel sulfer limit of 3.50 % - Fuel Oil Regulations Frequently asked questions
1. What is the enforcement date for this regulation?
A. From 1 January 2012, the MARPOL Annex VI global fuel sulfur limit for fuel oil will be
reduced from 4.50% to 3.50%.
2. Who is responsible for the 3.50% limit? Is the onus on the supplier or the fuel user?
A. All bunker suppliers inclusive of those supplying fuel oils outside of ECAs will have to
comply with the new limit. This is in line with Regulation 14.1 of the Revised MARPOL
It is important for ship-owners and operators to ensure that any fuel oil on board their
vessels with sulfur content exceeding 3.50% be fully consumed before 1 January 2012
and any future deliveries comply to the 3.50% limit.
3. If a ship is carrying fuel with sulfur greater than 3.50% on Jan 1 2012, will it be allowed
to use up this fuel?
A. There is no provision for a period of grace as to the implementation of the 3.50 % limit.
Furthermore there is no policy or period of grace as to vessels using up their stocks of
fuel greater than 3.50 % beyond this date. From the point of view of supply - clearly if
fuel is found to have been supplied above 3.50 % after 1st
January 2012, it would be non
4. Will the authorities be tolerant of breaches of the limit?
A. No, we are told there is no grace period for the implementation since there has been a
long notice period for the changeover. However a specific state port may use its
discretion but, to be on the safe side, it is better to assume that there will be no grace
5. Is the limit exactly 3.50% and is the ISO 4259 be allowed on it?
A. Applying the principles defined in ISO 4259 when testing a fuel using test method ISO
8754:2003, a fuel can be said to meet a 3.50% sulfur limit with '95% confidence' if a
single test result falls within the ranges of 3.32% sulfur to 3.68% sulfur.
However, the Marine Environmental Protection Committee (MEPC) of IMO, approved, on
April 4, 2008, Unified Interpretations with regards to 'Sulfur Limits in Fuel and Fuel Oil
Verification Procedure for MARPOL Annex VI', which the IMO says "should be applied
from the date of approval and until the 2008 amendments to MARPOL Annex VI enter
into force." The Unified Interpretations represent a tightening of the sulfur limit
Firstly, sulfur limits previously stated as 4.5% globally and 1.0% in a sulfur emission
control area under regulation 14 of MARPOL Annex VI are to be interpreted with two
decimal digits, 4.50% and 1.00% respectively. Secondly, a verification procedure has
been agreed for those cases when a port state control officer (PSCO) decides to check a
ship's MARPOL bunker sample to determine whether the fuel oil delivered to the ship is
compliant with the standards required under MARPOL Annex VI.
Since the 4.50% limit is coming down to 3.50%, the Unified Interpretations means that
ultimately, a final test result in accordance with the verification protocol of 3.51% sulfur
would be considered as failing the 3.50% sulfur standard.
Traditionally, when it came to disputes about sulfur test results, the prevailing argument
was to apply the repeatability (r) and Reproducibility (R) principles found in ISO
standard 4259 when testing a fuel using test method ISO 8754:2003. The reproducibility
(R) for sulfur of 3.50% comes to 0.296%. 95% confidence value comes to 0.59 X R or 0.59
X 0.296 which comes to 0.18%. According to those principles, a fuel can be said to meet a
3.50% sulfur limit with '95% confidence' if a single test result falls within the ranges of
3.32% sulfur to 3.68% sulfur.
The new two-digit interpretation combined with the strict sulfur verification protocol
will require suppliers to provide fuels with 3.32% sulfur to ensure they do not exceed the
3.50% sulfur limit with 95% confidence.
6. How to ensure that the fuel bunkered will never cross 3.50% no matter where it is
A. We would actually suggest purchasing fuel with sulfur of 3.50% - (R) where R is the
reproducibility. This would mean to less than 3.20%. This way it is ensured that if the
supplier tests the sample as 3.20% even if the state port draws a sample from the tank
and gives it to a lab of its choice to test the sulfur, the sulfur will be found to be less than
3.50%. It is possible that the supplier may ask for a higher price for lower sulfur content
7. If not allowed to use up this fuel, how to deal it?
A. Fuel with sulfur greater than 3.50% can be blended with a heavy fuel or MDO to reduce
the sulfur content. Detailed records of the blending (including BDN's of the two fuels
being blended) must be kept. A sample of the blended fuel should be sent to the lab for
confirmation that the blend has sulfur less that 3.50%. This lab report can also be shown
to the surveyor. To be safe, the sampling can be carried out by a 3rd
party survey firm.
8. What is the best way to blend to bring down sulfur content? Another HFO or MDO?
A. Blending high sulfur HFO to low sulfur HFO is preferable to blending with MDO/MGO
to bring down sulfur. Compatibility of the fuels must be checked before any blending is
carried out. Viscosity will be seriously affected when HFO is blended with MDO/MGO. For
example if 10% MDO is added to a 380 cSt HFO, the viscosity will drop from 380 cSt to
180 cSt. Please keep this factor in mind.
9. Is onboard blending allowed? Any points to note while blending
A. Blending onboard is not advisable. If it is unavoidable, first check for compatibility. The
compatibility can be checked onboard using the attached procedure (Annex 1). The
compatibility can also be checked in the fuel testing lab. Secondly, the blending has to be
carried out in a certain order. A lower density fuel should be pumped on top of a higher
density fuel, circulate the fuel as much as possible, heat the fuel to achieve mingling
through thermal convection currents.
10. How is the sulfur limit enforced?
A. The standard procedure is for the port state surveyor to ask for the BDN( Bunker delivery note). It is possible
that he can ask for a lab certificate for the sulfur content. The third possible scenario is
that the port state surveyor may draw a sample from the service tank and give it to a lab
ashore for checking on the sulfur content.
11. Will Port State Surveyor take the Marpol sample supplied by the supplier or will he
draw sample from service tank?
A. The port state surveyor has the option of choosing the MARPOL sample for testing or drawing a sample from the service tank.
12. What are the penalties if a vessel using fuel that has sulfer limit exceeding 3.5 % ?
A. Detention of the ship is one. Stiff fines may also be levied.
13. Under what conditions will greater than 3.50% be accepted.
A. If abatement equipment (such as scrubbers) is fitted onboard, fuel with sulfur more
than 3.50% can be used.
14. Are there several areas in the world where sulfur at greater than 3.50% is supplied?
A. The global sulfur value for heavy fuels of all grades is 2.35% for the year 2011. 7.3% of
the deliveries were higher than 3.50%. There are some countries which have average
sulfur close to or over 3.50% with a significant number of deliveries over 3.50%. These
Bunker fuel purchase agreements and charter party agreements have to be suitably
amended to reflect the 3.50% sulfur limit.
Following information to be included in the Bunker Delivery Note.
- Name and IMO number of receiving ship
- Bunkering Port
- Date of commencement of delivery
- Name, address, and telephone number of marine fuel oil supplier
- Product name
- Quantity (metric tons)
- Density at 15 (kg/m3)
- Sulphur content (% m/m)
Further, the seal number of MARPOL sample label to be included in the Bunker Delivery Note for cross-reference purposes.
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