UN 3378 Sodium Percarbonate: Why Container Fires Involving This Oxidiser Need a Different Plan

Why An Oxidiser In A Box Is A Fire Risk

North Standard has issued an alert on container fires involving UN 3378, sodium carbonate peroxyhydrate, a white granular powder used in laundry products, cleaning products and bleaching. We have not been able to retrieve the full text of the alert, so this article sets out what crews need to know about the substance in general and points you to the Club's alert for the details.

The key point is that UN 3378 is a Class 5.1 oxidising substance. It does not burn by itself in the way a fuel does. It releases oxygen when it decomposes and so makes any nearby combustible material burn harder and faster. Safety data sheets for sodium percarbonate describe decomposition driven by heat, moisture and contamination.

What Crews Should Check

1. The declaration. Check the dangerous goods declaration and container packing certificate for the correct proper shipping name, UN number, class and packing group. A fire involving a misdescribed oxidiser is a different fire from the one the stowage plan assumed.
2. Segregation and stowage. Apply the IMDG Code segregation and stowage provisions for Class 5.1 against flammable and combustible cargoes, and keep it away from heat sources.
3. Moisture and contamination. Wet or contaminated packaging is a warning sign. Water ingress or contamination can start decomposition. Report damaged or wet units rather than loading them.
4. Temperature. Consider heat from the deck, funnel, machinery spaces and direct sun when allocating positions.
5. Fire plan. Know your fire response for Class 5.1 before you need it. Check the substance's safety data sheet and the IMDG EmS entry for the correct medium. Safety data sheets for sodium percarbonate generally point to large quantities of water, but a container fire on a ship is a command decision supported by company and specialist advice, not a bridge guess.
6. Boundary cooling. Container fires spread by heat transfer to adjacent units. Boundary cooling is often the first practical action, within the limits of crew safety.

A Reminder From The Record

Containers of sodium carbonate peroxyhydrate have featured in previous container ship fires. Press reports of the 2021 fire aboard the container ship Interasia Catalyst at Port Klang, Malaysia noted that three of the affected containers held it. We make no claim about the cause of that fire. We cite it only to show this class of cargo has been present in major container fires before.

Why It Matters To You

A container fire is a long fire. Most of a ship's crew will never fight a fully developed container fire, which is why the decisions made at stowage planning and loading matter more than any made at the fire. If you are a Chief Officer reviewing the cargo plan, UN 3378 is a good test of whether your team knows what a Class 5.1 entry in the dangerous goods manifest actually means.

Test Your Knowledge

Think you've got this covered? Put it to the test in Crew Connect's free Knowledge Checker — try a quick cargo round and see how you score.

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