Nitrogen Supplementary Sign

IMO Nitrogen Supplementary Sign – FS0029

This nitrogen supplementary sign displays the letter “N” to identify nitrogen as the extinguishing or inerting medium associated with a fixed fire suppression system or storage cylinder. It is used alongside fire control plan symbols and equipment labels to clearly distinguish nitrogen installations from other gas-based systems such as CO2 or halon.

Correctly identifying the extinguishing medium at a glance is critical for crew responding to a fire or carrying out maintenance, since different gas systems require different handling, ventilation, and safety precautions. This nitrogen supplementary sign removes any ambiguity about what a cylinder bank, release station, or protected space actually contains.

Where this nitrogen supplementary sign is used

This nitrogen supplementary sign is fitted at nitrogen cylinder storage rooms, inert gas system controls, and spaces protected by nitrogen-based fire suppression or inerting systems, commonly found in machinery spaces, cargo tank protection systems, and certain specialised compartments. It is used alongside other fire control plan symbols to build a complete picture of a vessel’s fixed fire suppression arrangements.

Installing this nitrogen supplementary sign is straightforward: apply using the sign’s adhesive backing or fixings directly on or beside the relevant cylinder, control panel, or space entrance. Crew should be trained to recognise this nitrogen supplementary sign during fire control plan briefings, understanding that nitrogen systems work by displacing oxygen and require particular care regarding personnel safety before and during a release.

Regulatory context

Fixed fire suppression and inerting systems, including nitrogen-based systems, are addressed under SOLAS Chapter II-2 and the Fire Safety Systems Code, which set requirements for identification, signage, and safe operation of such systems. Surveyors reviewing fire control plans and equipment during inspections check that a nitrogen supplementary sign is present wherever nitrogen systems are installed, and that it matches the equipment.

Clear and accurate nitrogen supplementary signage supports crew safety by ensuring nobody mistakes a nitrogen installation for a different gas system, which is particularly important given the asphyxiation hazard nitrogen release presents in enclosed spaces.

Technical specifications:
SKU: FS0029
Compliant: IMO Resolution A.1116(30)

• Photoluminescent material for visibility in low-light and emergency conditions
• Durable construction suited to marine environments
• Complies with IMO/SOLAS signage requirements
• Easy to install using adhesive backing or fixings
• Long-lasting, resistant to fading and marine wear
• Standard size, custom sizes available on request

Manufactured to IMO photoluminescent standards, this sign is part of our full range of Fire Fighting Signs.

Need a different size? Contact us for a quote.