FMP
Flow Moisture Point
FMP is the moisture percentage at which a flow state is reached under the applicable test method. It is a laboratory flow point.
An FMP result is not, by itself, a decision that cargo is suitable for carriage.
AHK Mersin Laboratory
FMP & TML Testing
For solid bulk cargoes, correct assessment of FMP, TML and actual moisture content is a critical safety step in managing liquefaction or dynamic-separation risk and vessel stability.
The test method, cargo classification and current IMSBC / competent-authority requirements must be considered together.
Vessel stability
This risk is not theoretical.
More than a laboratory value
Moisture-sensitive solid bulk cargoes can lose strength under ship motion and compaction. Fluid-like behaviour or, for some cargoes, separation of a liquid layer can lead to cargo movement and free-surface effects, creating dangerous list, loss of stability and sudden-capsize risk.
Core definitions
FMP and TML are not the same
TML
Transportable Moisture Limit
TML is the maximum moisture content considered safe for applicable Group A cargo under ordinary carriage conditions, determined using an approved test procedure.
The relationship between FMP and TML depends on the applicable method; there is no single universal formula for every cargo.
Technical risk chain
From moisture to loss of stability
Cargo can appear relatively dry from the outside. Risk can develop when moisture within the material changes cargo behaviour under ship motion and compaction.
- 01
Moisture-sensitive cargo
Fine-grained or moisture-sensitive solid bulk cargo.
- 02
Ship motion and compaction
Movement, vibration and cargo compaction during the voyage.
- 03
Loss of strength
Liquefaction or dynamic separation for some cargoes.
- 04
Cargo movement
Fluid-like behaviour and free-surface effects where applicable.
- 05
Dangerous list
Reduction in righting ability and stability margin.
- 06
Capsize risk
Sudden loss of stability, vessel loss and risk to life.
From sample to decision
Representative sampling and actual moisture are assessed together
A laboratory result is meaningful only when the tested sample represents the cargo. Moisture and physical characteristics may vary between stockpiles, lots or different parts of a shipment.
Representative sampling servicesA TML result is not sufficient on its own
The actual moisture content of a representative cargo sample must also be determined and assessed against the applicable TML.
- Rain, drainage, handling, segregation, blending or material changes can affect sample representativeness.
- If conditions change materially, an earlier result may no longer represent the cargo at loading.
- The need for renewed sampling and testing is assessed under current IMSBC and competent-authority requirements.
Real casualty evidence
The consequences of moisture-related cargo instability
Official IMO records show why losses associated with liquefaction or moisture-related cargo instability must be considered in a maritime-safety context.
44
lives lost · three bulk carriers
IMO reported that three bulk carriers sank while transporting nickel ore in 2010, with 44 lives lost in total, in incidents reported as allegedly involving cargo liquefaction affecting vessel stability.
18
fatalities · Bulk Jupiter
In 2015, Bulk Jupiter sank rapidly while carrying approximately 46,400 tonnes of bauxite, with 18 fatalities. IMO reported investigation evidence linking moisture-related cargo instability with loss of stability. Subsequent research also highlighted dynamic separation as an important risk for certain fine bauxite cargoes.
These events do not predict an identical outcome for every cargo. They demonstrate why representative sampling, an applicable method, actual moisture and current carriage requirements must be considered together.
Local laboratory and field support
AHK Mersin Laboratory
AHK Turkey’s Mersin Laboratory provides FMP/TML testing and moisture determination services. Where required, our field teams can coordinate representative sampling and dispatch of samples to the laboratory.
The Mersin Laboratory holds ISO/IEC 17025 accreditation from TÜRKAK under AB-1208-T. The current official TÜRKAK scope should be consulted to confirm the accreditation status and applicable method for a specific FMP/TML requirement.
Frequently asked questions
About FMP / TML
What is FMP?
FMP is the moisture percentage at which a flow state is reached under the applicable test method. This laboratory flow point is not, by itself, a decision that cargo is suitable for carriage.
What is TML and how is it different from FMP?
TML is the maximum moisture content considered safe for applicable Group A cargo under ordinary carriage conditions. FMP is the laboratory flow point; TML is the transport limit. Their exact relationship depends on the applicable approved method.
What are the risks if FMP/TML is incorrectly determined or cargo moisture exceeds the TML?
Moisture-related instability can lead, where applicable, to liquefaction or dynamic separation, cargo movement, dangerous list, loss of stability, sudden capsize, vessel loss and risk to life. This is not simply a laboratory issue relating to cargo quality; an incorrect assessment can directly affect vessel stability and safety of life.
Why is representative sampling critical for FMP/TML testing?
Moisture and physical characteristics can vary between stockpiles, lots or different parts of a shipment. A laboratory result contributes to a reliable assessment only when the sample represents the cargo.
Is the FMP/TML result enough on its own, and why must actual moisture content also be determined?
No. The actual moisture content of a representative cargo sample must also be determined and assessed against the applicable TML.
Should the assessment be repeated after rain or changes in cargo conditions?
Rain, drainage, handling, blending or material changes can affect representativeness. The need for renewed sampling and testing should be assessed under current IMSBC and competent-authority requirements.
Technical references
Official and high-authority sources
The links below provide authoritative sources for current requirements, methods and official casualty information.
- 01IMO — IMSBC Code
The official framework for safe carriage of solid bulk cargoes.
- 02IMO — 2010 nickel-ore losses
Official IMO statement on three vessels and 44 lives lost.
- 03IMO — Bulk Jupiter
Official account of 46,400 tonnes of bauxite, rapid sinking and 18 fatalities.
- 04IMO — Dynamic separation in bauxite
Later research summary on fine bauxite and free-surface effects.
- 05ISO — ISO 12742:2020
Official standard page for specified copper, lead and zinc sulfide concentrates.
- 06TÜRKAK — Accredited organisation search
The service for verifying the current official AB-1208-T scope.
Laboratory enquiry
Discuss your FMP/TML, moisture or sampling requirement
Contact our Mersin laboratory to discuss FMP/TML testing, moisture determination or related sampling requirements.