Microbial growth may occur wherever any water accumulates in diesel and gas oil fuel tanks and systems. Water may form by condensation and also may be introduced during bunkering, if the fuel supplier does not have adequate fuel handling and quality control procedures.  Fuel bunkered from barges is particularly prone to water contamination.

When the presence of water allows heavy microbial growth to occur, fuel quality can be affected. If tank contents are disturbed, for example during tank filling, microbial biomass becomes suspended in the fuel and it can then plug fuel filters, block fuel lines, foul fuel injectors and cause engine damage. Diesel fuel contamination has also caused failure of power generators on offshore platforms leading to delays in production.

Modern diesel fuels supplied for marine use may be particularly susceptible to microbial growth due to the presence of biodiesel (Fatty Acid Methyl Esters or FAME); some specifications allow blending of biodiesel at up to 7% but even fuels which do not intentionally contain FAME have be shown to contain FAME as a contaminant.  The current ISO 8217 DMA specification for marine fuel allows a de minimis FAME concentration of 0.1%, but it is proposed to increase this to 0.5%.

It has also been suggested that low sulphur fuels may be more inherently susceptible to microbial growth, but further research needs to be conducted to fully establish the reasons for this.

ECHA can;

• Conduct analysis of samples of fuel from your vessel or facility in our laboratory to assess the extent of microbiological fuel contamination. Learn more about our lab analysis service here.
• Provide on-board microbial Test Kits. ECHA’s MicrobMonitor2 is a globally recognised industry standard test (IP 613/ASTM D7978) which can be used on-site or in the laboratory by non-microbiologists for the detection of microbiological contamination. Learn more about the test here.
• Conduct surveys of tanks and systems on board your vessel or platform if you have a concern about microbiological contamination. Learn more about our Site Surveys here.
• Provide advice on remediation, control, monitoring strategies and best practice. Learn more about our Consultancy Services here.
• Offer comprehensive, tailored training courses on microbiological contamination of marine fuels. Learn more about our Training Courses here.