Operational guide · Operational procedure

MARPOL Annex III: Harmful Substances Carried in Packaged Form

Package and CTU marking follows specific IMDG provisions, including the 5 L/5 kg package exception; spill reporting follows MARPOL Article 8/Protocol I and is coordinated with SMS and safety reporting.

MARPOL Annex IIImarine pollutantIMDG

Operational Explanation

IMDG 2.10.2.7 concerns net quantities per single or inner packaging: liquids ≤5 L, solids ≤5 kg, subject to the prescribed general packaging conditions. The exception covers other IMDG provisions relevant to marine pollutants, not only the package mark. Requirements for any other hazard classes remain applicable. PHMSA: IMDG 2.10.2.7.

Regulatory Reference

MARPOL Annex III and IMDG Code for harmful substances in packaged form. Incident reporting: MARPOL Article 8 and Protocol I, A.851(20) guidelines as amended, and current national operational contact points.

Protocol I also covers probable discharge of harmful substances in packaged form: do not necessarily wait for confirmation of a release into the sea. Apply required recipients, timing and report updates, coordinating with other duties. IMO: MARPOL Protocol I.

Scope of Application

For each consignment check environmental classification, packaging type and single/inner quantity. CTU marine pollutant marking follows IMDG 5.3.2.3.1, which references the 2.10.2.7 exception: assess all contents, including other non-exempt consignments.

Procedure / How to Complete It

Determine marine-pollutant status from DGL and special provisions.
Apply package mark and CTU placarding/marking under their respective rules.
Assess the ≤5 L liquid or ≤5 kg net solid package exception only where general packaging provisions are met.
On spill activate emergency response/SMS and protect people and ship.
Assess reportability under MARPOL Article 8/Protocol I and coastal/port duties; report without delay to applicable recipients/contact points.
Coordinate safety, dangerous-goods and pollution reporting without duplication or omitted recipients.

Practical Example

A CTU contains only packages satisfying 2.10.2.7: those consignments do not require its marine pollutant mark. If it also contains non-exempt marine pollutants, reassess CTU marking. Other hazard classes and their requirements must still be checked.

What Typically Goes Wrong

Confusing the 2.10.2.7 exception with a package-mark-only exemption, or applying it without checking quantities, packaging and other hazards. Incident reporting remains a separate assessment.

Common Mistakes Mistake Library

Mistake	Consequence	How to avoid it
'MARINE POLLUTANT' marking not applied because it is considered redundant relative to the primary IMDG class labelling	Non-compliance with MARPOL Annex III even when the IMDG safety classification is correct	Always apply the specific marine pollutant marking when required, in addition to, not instead of, the primary class labelling
Transport documentation showing only the primary IMDG hazard classification, omitting marine pollutant status	Documentation incomplete for the purposes of MARPOL Annex III	Check and explicitly include marine pollutant status in the documentation, when applicable
Reportability under MARPOL Article 8/Protocol I and applicable coastal or port duties not assessed within the emergency response	Failure to comply with specific environmental notification obligations in the event of a spillage	Integrate the applicable pollution report, recipients and current national contact points with safety and dangerous-goods reporting

What the PSCO Checks

Port State Control Officers (PSCOs) check that substances classified as marine pollutants under the IMDG Code carry the specific marking required and that the transport documentation gives explicit evidence of this, in addition to checking the primary safety classification.

Operational Tips

Treat marine-pollutant status under the applicable package, CTU and documentation provisions, including the conditional 5 L/5 kg package exception.
Always check the marine pollutant status of every substance carried, regardless of its primary hazard class, since the two classifications follow different logics.
Integrate pollution reporting with the safety emergency response under MARPOL Article 8/Protocol I and applicable coastal or port requirements, without unnecessary duplication.

Preparation checklist

Marine-pollutant status checked
Package mark and CTU marking separated
5 L/5 kg exception used only within scope
Emergency/SMS response ready
MARPOL Article 8/Protocol I assessed
Current contact points and coordinated reporting

FAQ

Must every marine-pollutant package always bear the mark?

No. The ≤5 L liquid or ≤5 kg net solid exception may apply if IMDG conditions are met.

Does the package exception automatically remove CTU marking?

CTU rule 5.3.2.3.1 references 2.10.2.7. If all marine-pollutant consignments meet the exception, the CTU marine pollutant mark is not required; check other non-exempt consignments and other hazard classes.

Does Annex III always require a report separate from safety reporting?

No. Reporting derives from MARPOL Article 8/Protocol I and applicable duties; flows may be coordinated without omitting recipients.

MARPOL Annex III: Harmful Substances Carried in Packaged Form

Operational Explanation

Regulatory Reference

Scope of Application

Procedure / How to Complete It

Practical Example

What Typically Goes Wrong

Common Mistakes Mistake Library

What the PSCO Checks

Operational Tips

Preparation checklist

FAQ

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