To support this, we are collecting very low sulphur fuel oils from visiting ships to analyse their properties, to better understand the behaviour, from these new oil products.

Every oil, whether fuel or cargo, is different. Some are heavy and spread slowly, others are light and evaporate quickly, and every combination in between. This diversity in characteristics mean that when they spill, they may require quite different strategies to effectively clean up. 

The key to mounting an effective response to a pollution incident is knowing how the pollutant (the oil) will behave once it is spilled. 

Our intention is to understand the nature of any potential pollutants so we can protect the community and spill responders, minimise harm to the environment and maximise clean-up effectiveness.

Read more information on the National Plan for Maritime Emergencies.

Initial samplings

To determine how fuel oils might behave if spilled into the Australian marine environment, AMSA will have the oil analysed for the following properties:

• Density (how well it will float)
• Pour Point (at what temperature it will spread on the water)
• Viscosity (how well it spread or evaporate)
• Asphaltene content (whether it will thicken up with when mixed with water)

Understanding the oil’s properties can provide an insight into what the ultimate fate of the spilled oil may be – this is called weathering. Some will evaporate, lowering the volume to be cleaned, but the vapours might also create a fire hazard. Some might get mixed with water and become so dense it sinks, making for more difficult containment. Some might mix with water and become thick and sticky (viscous) and create a mousse, which is hard to collect. A mixture with water can even multiply the total volume to be cleaned, resulting in more sticky oily substances to cleaned off beaches, wharves or wildlife. 

Based on the initial seven samples analysed from international ships visiting Australia in 2020, it was found that the new VLSFOs:

• Are diverse and variable in their manufacture and presentation.
• Appear to offer lower responder hazard risks from explosion or vapours when compared to earlier higher sulphur fuel types carried on ships prior to 2020.
• Appear to be likely to behave differently once spilled, compared to pre-2020 oils, but because of their diversity of character and properties, more analysis is needed to be sure for each type. 
• Appear to be slightly easier to contain and clean-up than pre-2020 fuel oils, so existing clean-up technologies are likely to be more effective. The small sample size, limited number of places the fuels were made, and limited number of tests completed, mean that the next phase of sampling and testing will bring much more definitive results. 

Further sampling

We will be undertaking a wider sampling and analytical effort on the heavy VLSFO’s throughout 2021. 

Sampling a larger number of ships, will mean that a wider range of fuel source ports and bunker suppliers can be assessed. 

The ships sampled will come from a wide range of ports of origin, across both sides of the North Pacific, the Indian Ocean, and Europe, as well as some from Australian ports. 

AMSA ship inspectors will be seeking the necessary consent to undertake the extra analysis on the samples collected. Every ship in the study will have its fuel analysed for its sulphur content anyway, as part of our IMO2020 low sulphur fuel compliance program.