IMO warns shipping over ammonium nitrate-based fertilisers

Fertiliser is loaded onto a vessel. Credit: Getty Images

The International Maritime Organization (IMO) has warned the shipping community to exercise “extreme care” and take “appropriate action” in the handling of ammonium nitrate-based fertiliser cargoes.

The warning has come after the spectacular decomposition of the fertiliser cargo of the Bibby Line vessel Cheshire off the Canary Islands in August, which itself was the latest in a series of incidents involving vessels carrying ammonium nitrate-based fertilisers.

It was issued by the IMO in the form of a circular in September, a few days after a meeting of its carriage of cargoes and containers (CCC) subcommittee, but was paid little attention to at the time.

The IMO called on its member states to bring its recommendations to the notice of all concerned parties, including shipping companies, shippers, and terminal operators.

The committee’s recommendations have, arguably, more to do with an earlier incident involving the transportation of fertilisers than with this summer’s incident involving the Cheshire, which saw the vessel’s crew evacuated and the vessel left to drift for several days in the Atlantic before salvors were able to get a tow line to it.

In May 2015, the MACS-operated multipurpose vessel Purple Beach was abandoned by its crew off Germany’s North Sea coast after fertiliser in its holds began decomposing, causing smoke to billow from the vessel and creating fears that an explosion was about to occur.

Germany has been pressing at the CCC committee for a higher risk rating for ammonium nitrate-based fertilisers. They are currently classed as a group C non-hazardous cargo by the IMO. Germany has proposed classing them in Group B in the materials hazardous only in bulk category.

The chemicals industry view, however, confirmed by recent test results, is that ammonium-based fertilisers are not dangerous and that their reclassification in Group B would not be justified.

This position is reflected in a recent response from Yara International, owner of the NPK (nitrogen-phosphorus-potassium) fertiliser being transported by the Cheshire, to questions put by Fairplay. The group said that it had no plans to change the way it transported its products by sea following the Cheshire incident.

The CCC committee has left the issue open for the time being but it seems that the German proposal did not meet with widespread support from other committee members.

The work of the committee has been hampered by the fact that there has still been no official accident investigation report from the German authorities on the Purple Beach incident. There has been no official report either on the much more recent Cheshire incident.

In addition, an earlier incident involving the cargo ship Ostedijk off the coast of Galicia in northwest Spain in 2007 was not made the subject of official accident investigation reports either by the vessel’s flag state – Antigua and Barbuda – or the coastal state – Spain.

The committee nevertheless noted that, in the Cheshire and Purple Beach incidents, the vessels and the sea areas surrounding them were enveloped in clouds of gas containing highly toxic vapour.

“Such conditions could affect the safe abandonment of the ship and hinder rescue and firefighting efforts,” the committee said. “In such events, decomposition may last for multiple days and the temperature in cargo holds may reach in excess of 500°C.”

Although the causes of the Purple Beach and Cheshire incidents have yet to be officially established, the committee recognised that exposure to a strong heat source could cause ammonium nitrate-based fertilisers to decompose and release toxic gases.

“The best protection for seafarers,” it said, “is awareness of the decomposition process to allow it to be identified at an early stage. Regular monitoring of the cargo throughout the voyage is crucial to detect beginning of decomposition”.

Industry body Fertilizers Europe has already issued its own safety instructions for the transportation of ammonium nitrate-based fertilisers by sea. These include, notably, avoiding contact between these fertilisers and combustible and other potentially incompatible substances and heat sources.

In its circular, the IMO also made recommendations regarding actions to be taken in the event that cargo decomposition had already started. It said that:

- maximum ventilation was necessary to evacuate the gases generated;

- protective clothing and breathing apparatus should be used if necessary;

- water should be applied by injection pipes so that it could be delivered directly to hot spots in the cargo holds;

- flooding of cargo could be considered subject to due consideration to vessel stability and structural strength.

It warned, however, that the use of shipboard gas firefighting installations would, be ineffective.

Contacted by Fairplay, Germany’s Federal Ministry for Transport and Digital Infrastructure declined to discuss its reaction to the committee’s conclusions or to the recent Cheshire incident, saying only that the IMO September circular to member states reflected its position.

It added, however, that the Federal Bureau of Maritime Casualty Investigation was co-operating with its British counterpart in the investigation into the incident involving the Cheshire.

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