PU foam on standby after tanker spillage

Yorkshire, UK – A collision between a US-flagged oil tanker and a Portuguese-flagged cargo ship in the North Sea has left one crew member missing and the captain of the cargo ship under arrest on suspicion of gross negligence manslaughter, but the environmental fallout from the incident remains unclear.

Although early fears that the cargo vessel, the MV Solong, was carrying sodium cyanide have been dispelled, the status of the 220,000 barrels of jet fuel aboard the oil tanker is uncertain. At least one cargo tank is reported to have ruptured.  

Jet fuel is essentially kerosene, a light hydrocarbon. It is lighter than crude oil, but would need to be removed from the surface of the water, potentially using polyurethane foam, to prevent bioaccumulation.

Speaking to Urethanes Technology International, Dr Jonathan Paul from the Department of Earth Sciences at Royal Holloway, University of London, said: “I suspect the authorities might wait a day or so to see what has happened to the kerosene plume. It might be ok to do relatively little, owing to the salt and currents of the local area.

“PU foam has been used quite effectively to remove aqueous contaminants in the past; equally, the use of surfactants on a grand scale could neutralise the oil. It really depends on the grade of hydrocarbon released [it seems a lot of fuel oil has also leaked into the North Sea].”

PU foam works by adsorbing the fuel, because of its oleophilic properties, and expanding like kitty litter. This removes the oil from the aquatic environment, and it can be skimmed off the surface. Paul added that certain types of bacteria could also break down the fuel, but PU foam has a much more immediate effect.

In a statement, shipping company Ernst Russ, which operates MV Solong, confirmed that four empty containers had previously contained sodium cyanide, and would continue to be monitored.

“Our team is actively engaged with all local authorities, and we will work with clean-up teams to ensure every effort is made to mitigate further impacts on the marine environment,” it said.

Crowley, which manages the tanker, said that it remains uncertain what volume of fuel might have been released, but "initial review shows impacts have been limited due to exposure to the fire and evaporation of the Jet A1 fuel".

A spokesperson for East Riding of Yorkshire Council told Urethanes Technology International that it was early days in the clean-up operation, and further updates on the situation would be made in due course.