Liquid cargo contamination

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Liquid Cargo Contamination

We have recently experienced an increase in liquid cargo contamination claims, especially where the ‘First Foot Sample’ was found to be off-specification upon analysis.

Many of these claims occur when a cargo of Jet A1 Fuel, a kerosene-type jet fuel, is loaded into tanks that had previously carried other commodities such as Un-Leaded Gasoline(ULG 95). As a result, the cargo is found to be off-spec at their freezing point, flash point and conductivity.

Generally, when a first foot sample is found to be off-spec, questions are raised regarding the effectiveness of tank cleaning and pipeline flushing techniques. A detailed analysis of such claims has revealed that these are a contributing factor in the majority of claims.

In some cases, cargo tanks are issued with a Clean Tank certificate by attending surveyors, yet the first foot sample taken shows that the cargo is contaminated. In such cases,although the ship’s tanks are cleaned and well prepared, the pipelines still have residues of the previous cargoes which lead to contamination.

We recommend the following to our Members:

  • Review any existing on board procedures and ensure proper tank cleaning procedures are in place, including those that take into account aspects such as ensuring the vessel has adequate trim to enable a smooth operation.
  • Prepare a comprehensive tank cleaning plan. This may include, but is not limited to the following stages (as applicable) precleaning, cleaning, rinsing, flushing, steaming, draining and drying. The plan should cross-reference the cargo to be loaded with the previous cargoes carried in the designated tanks and reference should be made to various industry recommended tank cleaning manuals, such as Dr. Verwey’s Tank Cleaning Guide. The charterer’s tank cleaning instructions should take precedence over these recommended methods. However, if they are of a lesser standard the same may need to be brought to the charterer’s attention in advance; the onus of presenting tanks fit to load the designated cargo usually rests with the Member.
  • Ensure suitable training is imparted to ship officers on the above mentioned procedures and if possible, tank cleaning operations are monitored for effectiveness by the shore office.
  • Ensure adequate sampling to safeguard the Member’s interests against possible claims.Please refer to our earlier Lookout, Reissue of Sampling Procedures for Clean Product Tankers for further guidance.

We would like to take this opportunity to kindly remind all our Members on the importance of carrying out proper tank cleaning and pipeline flushing in an effort to minimise their exposure to such claims.