Background
MARPOL AnnexVI, adopted under the International Convention for the Prevention of Pollution from Ships, sets limits for nitrogen oxides (NOx), sulphur oxides (SOx) and other airborne emissions. To verify compliance, the Annex requires regular fueloil sampling and analysis. The regulations apply to all vessels subject to the Annex, including tankers, bulk carriers, container ships and passenger vessels that use marine diesel oil (MDO), marine gas oil (MGO) or any other fuel containing sulphur.
Why Sample Fuel Oil?
- Verification of sulphur content: Ensures the sulphur percentage does not exceed the limit for the vessels designated Emission Control Area (ECA) or the global limit (0.50% m/m as of 2025).
- Demonstrating compliance: Sampling records are the primary evidence presented during port state control inspections.
- Detecting nonconforming fuel: Early identification of fuel that breaches the stipulated limits prevents fines and operational delays.
- Support for emission reporting: Provides reliable data for the Ship Energy Efficiency Management Plan (SEEMP) and any emissions inventories.
Key Regulations in AnnexVI
The most relevant paragraphs are:
| Regulation | Requirement |
|---|---|
| Regulation 13.1 | Ships must retain a fueloil sample for each batch of fuel used, labelled with date, time, location and fuel type. |
| Regulation 13.2 | Samples shall be taken at the point of fuel transfer (loading) and again at the engine bunker manifold within 24hours of the first sample. |
| Regulation 13.3 | Laboratory analysis must be performed by an accredited laboratory and the certificate retained on board for at least three years. |
| Regulation 13.4 | Ships Oil Record Book (PartII) must contain a dedicated section for fueloil sampling entries. |
Additional guidance is provided in IMO Circulars 286/90 (sampling procedures) and 310/93 (quality assurance). The European Unions Fuel Oil Sampling (FOS) regulation mirrors these requirements for ships calling at EU ports.
Standard Sampling Procedure
- Preparation
- Verify that the sampling kit (glass bottle, stopper, label, tamperevident seal) is clean and certified.
- Check the ships Sampling & Analysis Plan (SAP) for the specific fuel type.
- Sampling at the Bunker Pier
- Obtain the bunker delivery note (BDN) and note the fuel grade, supplier, quantity and sulphur specification.
- Insert the sampling probe into the delivery line at the specified point (usually at the top of the hose, before the fuel enters the manifold).
- Collect at least 250ml of fuel in the precleaned glass bottle. Avoid air entrainment.
- Immediately close the bottle with the provided stopper, seal it, and attach the tamperevident label.
- InShip Verification Sample
- Within 24hours, draw a second sample from the bunker manifold or fueloil transfer pump using the same kit.
- Label this sample INSHIP together with the earlier bunkerpier sample reference.
- Documentation
- Record the following in the Oil Record Book (PartII):
- Date and time of each sample.
- Location (pier or manifold).
- Fuel grade and quantity.
- Sample identification number.
- Enter the BDN details in the fueloil log sheet.
- Record the following in the Oil Record Book (PartII):
- Submission to Laboratory
- Dispatch the sealed bottles to an IMOaccredited laboratory within the timeframe stipulated by the flag state (usually 7days).
- Include a chainofcustody form signed by the officer responsible for sampling.
- Retain a copy of the analysis certificate on board; keep the original for the ships records.
Documentation & Record Keeping
All sampling activities must be reflected in the Oil Record Book (PartII). The required entries are:
- Entry number and date.
- Fuel type (e.g., MGO, VLSFO).
- Quantity transferred.
- Sampling point (pier or manifold).
- Sample identification code.
- Name and rank of the officer taking the sample.
Certificates of analysis (CoA) must be kept for a minimum of three years and be readily available for inspection. Digital copies are acceptable if the flag state permits electronic records, provided the files are backed up and protected against alteration.
Equipment Required
| Item | Typical Specification |
|---|---|
| Glass sampling bottles | 250ml, ambercoloured, capacity 300ml, DINEN 12895 compliant |
| Stoppers & seals | PTFE (Teflon) caps with tamperevident foil |
| Sampling probe | Stainless steel, 0.5in. diameter, with a 30mm vented tip |
| Chainofcustody form | Preprinted ISOstandard form |
| Protective gloves & goggles | EN388 certified chemicalresistant gloves |
| Label printer | Thermal printer capable of generating barcode IDs |
Equipment should be inspected annually and after any incident that could compromise its integrity. Replace any cracked bottles or worn stoppers before the next sampling cycle.
Frequently Asked Questions
- What if the laboratory rejects a sample?
- Collect a new sample immediately, following the same procedure, and submit it with a note explaining the previous rejection. Keep both certificates for the audit trail.
- Can electronic sampling devices replace manual bottles?
- Only if the device has been approved by the flag state and meets IMO guidelines for representativeness and traceability. Most authorities still require at least one physical bottle per batch.
- How are blended fuels handled?
- Take a separate sample for each individual component used in the blend, as well as a composite sample from the mixture before it enters the bunker manifold.
- Is there a minimum interval between two samples?
- The Annex does not prescribe a minimum interval, but the best practice is to sample each new fuel delivery and any subsequent change in fuel grade.
