BUNKER "C" FUEL OIL AND THE IRVING WHALE
Produced in August, 1995. Updated in March, 1996

What is Bunker C Fuel Oil?
"Bunker C" fuel oil is a term which has been used for many years to designate the most thick and sticky of the residual fuels. When steamships were coal-fired,"bunkers" was the home for the bins used to hold the coal. As marine diesel engines became prevalent, the term was carried over to include the liquid fuel tanks. At one time, the lighter fuel oils Bunker A and Bunker B were also available.

What does it look like?
Bunker "C" fuel oil is a sticky, black liquid similar in appearance and smell to asphalt sealing compounds. At 10° C it has a consistency of liquid honey or corn syrup. At 0° C it barely flows.

Where does it come from?
"Residual" fuel was originally defined as whatever liquid was left behind in the petroleum distillation unit after the removal of more valuable products like kerosene, diesel and naphtha. However, this type of fuel is no longer commonly available. Bunker "C" oil is currently produced by blending the oil remaining after the refining process with lighter oil.

What is it used for and why?
In addition to being used in the majority of large marine diesel engines, bunker oils are used in power generating stations, industrial boilers and furnaces, and pumping plants. Bunker oil is an inexpensive and readily available source of energy in many parts of the world.

How would Bunker C oil behave if it was spilled at sea?
Because it is less dense than water, fresh Bunker "C" fuel oil would float in water either at or below the surface. As the oil ages or "weathers", it becomes heavier, but it would still float under most conditions. If the oil comes into contact with sediment, sand or other shoreline materials, they may adhere together forming lumps or tar balls.

Is Bunker "C" oil toxic?
Bunker "C" fuel oil poses little threat to deep-water marine life because it does not disperse into the water column. The main threat to surface and shoreline organisms comes from the possibility of coating or smothering. Because it is a residual oil that contains few volatile organic compounds, Bunker "C" fuel oil is generally not toxic to plants or animals.

What oil sampling and analysis is involved with the Irving Whale?
Oil samples from the barge have been analysed at two Environment Canada laboratories to determine their physical and chemical properties. If oil spills during the recovery of the vessel, it will be compared with Irving Whale reference samples using various techniques to determine if the barge was the source of that oil.

For more information, contact:

Roger Percy, Environment Canada, (902) 426-2576
Vincent Jarry, Environment Canada, (514) 283-6418
Merv Fingas, Environment Canada, (613) 998-9622
OPERATION IRVING WHALE