Organic Chlorides in Bunker Fuels



  • Addition of organic chlorides by suppliers to create low-cost bunker fuels.
  • Formation of deadly hydrochloric acid causes severe damage to ships.
  • Organic Chlorides with boiling points above 135deg C and a 5ppm  presence are damaging to ship.
  • August and September saw 15+ cases of Organic Chlorides contamination with 100 to 1100 ppm presence.
  • October and November dealt with 13 cases with  30 to 800 ppm contamination.

What is the problem?

A well known shipping company in Central America was supplied with fuel from a distinguished supplier from the USA in 1994. The ship suffered total damage of fuel pumps, fuel nozzles, cylinders, piston rings etc. The vessel was paralyzed for over 25 days, while the owners desperately replaced every part. This is where the story of Organic Chlorides began for Viswa Labs, reads their latest technical report.

Where was the challenge?

The challenge of identifying the problem was presented to Viswa Lab after the owners failed to get any kind of diagnosis from other testing agencies. By knocking on several doors and assiduously looking for the cause, Viswa identified that the problems could be through the presence of Organic Chlorides. The problem fuel was tested for Organic Chlorides in two different labs and the result was 56 ppm and 51 ppm respectively.

Allowed limit on Organic Chlorides in fuel

Upon further investigation, Viswa confirmed that some refineries like Chevron did not allow crudes with more than 1.3 ppm Organic Chlorides. Many pipeline companies like Capline also restricted Organic Chlorides to 5 ppm. Obviously, the result of 51 ppm was totally unacceptable. For the first time in the marine bunker industry, Viswa utilized GCMS extensively to establish the presence of Organic Chlorides.

What are Organic Chlorides?

EPA lists several hydrocarbons with chlorine groups in several of their standards. Method 8121 lists the below as Organic Chlorides.

             Compound Name CAS Registry No.
Benzal chloride 98‐87‐3
Benzotrichloride 98‐07‐7
Benzyl chloride 100‐44‐7
2‐Chloronaphthalene 91‐58‐7
1,2‐Dichlorobenzene 95‐50‐1
1,3‐Dichlorobenzene 541‐73‐1
1,4‐Dichlorobenzene 106‐46‐1
Hexachlorobenzene 118‐74‐1
Hexachlorobutadiene 87‐68‐3
Hexachlorocyclohexane (‐BHC) 319‐84‐6
Hexachlorocyclohexane (‐BHC) 319‐85‐7
‐Hexachlorocyclohexane (BHC) 58‐89‐9
Hexachlorocyclohexane (‐BHC) 319‐86‐8


Effects of Organic Chlorides

The main reaction is the formation of Hydrochloric acid. This acid can easily eat through the lubrication film between a fuel pump plunger and barrel, also the fuel needle valve and guide, and also piston ring and cylinder liner. Very, very serious damage can occur in very short amount of time.

Low-cost bunker fuel

In this first case in 1994, the arbitration/litigation extended for over 2 years and resulted in the fuel supplier having to pay a huge compensation to the ship owner quite simply because Organic Chlorides have no business being present in bunker fuels. The only reason they were present is because they were added to the bunker fuel. Once again, it’s a case of low-cost cutter stock to further reduce the cost of bunker fuel and increase the margins for the bunker fuel supplier/trader.

Over a period of the time, the Organic Chloride problem has occurred several times and the pattern has been the same. This single contaminant group was responsible for making GCMS a familiar tool to investigate problem bunker fuels.

The Organic Chloride story does not end here. We have learned several important lessons in this developing story. For example, we detected Organic Chlorides at high levels but no damage was reported. This completely negated our theory and we investigated this further.

Variation due to boiling point

Out of the several Organic Chlorides found, about 5 of these compounds have boiling points less than 135 deg C. What happens in a marine diesel engine is that this group of Organic Chlorides (which vaporize under 135 deg C) did not cause any problems since they vaporized out of the bunker fuel and were perhaps vented out. But there are Organic Chloride compounds, with boiling points much greater than 135 deg C, which remain in the fuel and will definitely cause serious damage.

Identification of Organic Chlorides in fuel

Through the Viswa’s POMP/EPOMP program, the presence of Organic Chlorides is detected in the process of screening the fuel by GCMS. If these compounds are found, a detailed GCMS CRA is conducted which identifies each and every Organic Chloride. The fuel is then heated to 135 deg C to identify the compounds which have higher evaporation temperatures and those which are likely to cause damage provided the fuel contains more than 5 ppm.

Because of the high damage potential due to the presence of Organic Chlorides, Viswa Lab takes enormous care to carry out multiple tests to check on the evaporation of these Organic Chlorides compounds and to measure the quantity of these compounds.

This technical update is not a tutorial on Organic Chlorides, but an effort to spread awareness of the presence of this family of chemicals and its potential for causing damage. In August and September, Viswa Labs had over 15 cases of Organic Chlorides contamination, with levels varying from 100 to 1100 ppm. Between October and November, they dealt with 13 cases with Organic Chlorides contamination, ranging between 30 to 800 ppm.

Interestingly, Viswa Labs does not have any reports of damage caused by the presence of these Organic Chlorides. In these cases, in every instance, the vaporizing temperature of the compounds found was within 135 deg C and due to this most of the Organic Chlorides did not enter the fuel pump or fuel system and cause further damage.

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Source: Vishwa Lab


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