Fuels Technical Information

For many years some bunker suppliers have blended used lubricating oil (ULO) into bunker fuel. The acceptability of this practice has become a highly contentious issue and the industry is strongly divided.

Arguments presented for allowing used lubricating oil (ULO) in bunker fuels include:

• No conclusive evidence of any harmful effects of ULO at "low" levels
• Disposal of marine crank case oil in the fuel by some owners and therefore the disposal of ULO from land based sources is thought to be equally acceptable
• The impracticability of defining ULO because its composition is variable

The arguments presented for opposing the practice include:

• Concern about adverse effects on centrifuge performance
• Elevated ash levels from ULO addition which may lead to engine problems such as accelerated turbo charger fouling
• ULO from inland sources may provide a route for other waste materials to enter the bunker pool