August 26, 2025
The Global Centre for Maritime Decarbonisation (GCMD) has released the “Tracers for biofuels authentication: Evaluating the efficacy of tracer technologies in marine fuel supply chains” report on the world’s first field validation of tracer technologies in marine biofuel supply chains.
GCMD conducted six biofuel tracer trials in major bunkering hubs like Singapore and Rotterdam. These trials tested three tracer types and found that an organic tracer was the most effective for verifying the authenticity and quantity of biofuels, balancing cost, detectability, and scalability.
A total of 10,400 MT of biofuel blends was bunkered during the trials, achieving an average 24% reduction in GHG emissions compared to conventional fuels.
Currently, certification schemes (e.g., ISCC, RSB) verify sustainability claims but lack field-level validation, leaving biofuel supply chains exposed to adulteration and fraud. Tracer deployment offers a way to provide physical, verifiable proof of biofuel authenticity and volume, helping to close this assurance gap.
Testing under actual operating conditions
GCMD trialled three extrinsic tracer candidates — synthetic DNA (Tracer A), element-based metalloid (Tracer B), and non-fluorescent organic (Tracer C) — across six supply chain trials, deploying them at the earliest feasible upstream points and tracking them through to storage and use onboard receiving vessels.
In five of the six trials, the tracers were homogeneously distributed in both the neat biofuels constituent and their final blends, confirming their chemical compatibility.
- Tracer A was detected at most sampling points in its initial trials, but detection downstream was inconsistent, particularly on receiving vessels. In one trial, the tracer remained undetected despite multiple dosings, suggesting possible thermal denaturation of the synthetic DNA or matrix interference from contaminants in fuels.
- Tracer B was successfully detected at all sampling points and showed the highest tolerance to harsh operating conditions typical of marine fuel environments. However, discrepancies of 30-40% between expected and detected concentrations, particularly at the low parts-per-billion (ppb) deployment levels, point to the need for further optimisation for robust quantification.
- Tracer C was consistently detected at all sampling locations. At deployment concentrations below five parts-per-million (ppm), detected values closely matched expected concentrations, with discrepancies less than 5%. Its robustness, combined with cost competitiveness and detectability with commonly administered Gas Chromatography-Mass Spectrometry (GC-MS) tests, suggests that Tracer C holds significant potential as both a reliable identifier and quantifier in marine fuel supply chains.
Credit: GCMD Key outcomes
According to the report, this pilot showcased the feasibility of introducing tracer technologies into existing marine biofuel supply chains without disrupting operational practices or compromising fuel quality. Across six supply chain trials, three tracer candidates from three distinct tracer technologies—synthetic DNA, element-based, and organic tracers—were deployed.
While physical tracers are recognised as effective tools for fraud prevention across various applications, not all are equally effective for maritime use. The wide-ranging environmental conditions as well as the diversity of cutter stocks in the maritime industry make using tracers more complex than in other more controlled situations. This complexity means that more robust tracers have to be used.
Based on the performance in the supply chains in this pilot, GCMD’s trials indicate that the organic tracer deployed present the most practical solution for biofuels applications as they strike an effective balance between cost, detectability, and scalability, largely in part due to their compatibility with widely available GC-MS instruments.
GCMD’s trials have demonstrated the real-world viability of using tracers to track and authenticate sustainable biofuels by physically validating that they are derived from sustainably certified feedstocks and processed in accordance with their certification. With these results now publicly available, GCMD strongly encourages the adoption of tracers in commercial-scale applications to enhance supply chain integrity. However, robust and widespread deployment also requires strong institutional support, including legislation to establish:
- Controlled tracer deployment – ensuring tracers are applied in a precise and well-documented manner;
- Standardised protocols – enabling harmonised methods for dosing, sampling and detection;
- Seamless workflow integration – to maintain operational efficiency without adding bunkering delay; and
- Shared data systems – to enable real-time verification and auditability.
In parallel, harmonised operational protocols are needed to support scale-up. This includes:
- the integration of tracer technologies with complementary analytical tools, such as FAME fingerprinting and digitalisation platforms to strengthen the overall robustness and reliability of verification methods;
- the establishment of standardised protocols to promote the acceptance of tracers deployment to ensure consistent and reliable detection; and
- the formulation of policy recommendations to recognise/allow the use of tracers for dispute resolutions and carbon accounting within best practices and regulatory frameworks.
These steps are essential to unlocking the full potential of tracers as reliable physical validation tools for sustainable marine biofuels.
Our pilot has demonstrated the viability of physical tracers in safeguarding the integrity of marine biofuel supply chains. This was made possible through close collaboration with marine fuel suppliers, end-users, surveyors, testing laboratories, and tracer technology providers. By generating evidence-based data through comprehensive trials to combat fraud, we are fostering confidence for the widespread adoption of biofuels
… said Professor Lynn Loo, CEO of GCMD.
