How do IMO safety signs differ from standard workplace safety signs?

IMO safety signs differ from standard workplace safety signs in their governing standards, symbol sets, material requirements, and mandatory placement rules. Where workplace signs follow general occupational safety standards such as ISO 7010, IMO signs are governed by international maritime regulations that apply specifically to vessels subject to SOLAS conventions. The sections below unpack each key difference in detail, from symbol design and colour coding through to the legal consequences of using the wrong sign type on board.

What standards govern IMO safety signs?

IMO safety signs are governed by IMO Resolution A.752(18) and the ISO 15370:2021 standard, both of which define the symbols, colours, dimensions, and photoluminescent performance requirements for maritime safety signage. These are international maritime regulations, not general occupational health and safety frameworks, and compliance is mandatory for vessels operating under SOLAS.

Standard workplace safety signs, by contrast, are typically governed by ISO 7010 or regional equivalents such as EN ISO 7010 in Europe. These standards cover a broad range of industrial and commercial environments but were not designed with the specific hazards, escape route layouts, or operational conditions of a vessel in mind.

The distinction matters because IMO standards are enforced through port state control inspections and flag state audits. A vessel that cannot demonstrate compliance with IMO Resolution A.752(18) and ISO 15370:2021 faces detention, delays, and the cost of remedial work. General workplace standards simply do not satisfy these requirements, no matter how high their quality.

How do the symbols and colours on IMO signs differ from standard signs?

IMO signs use a dedicated symbol library developed specifically for the maritime environment, where crew and passengers may speak many different languages and must act quickly under stress. The colour conventions also differ: IMO signs follow a marine-specific coding system in which green indicates escape routes and muster stations, red indicates fire-fighting equipment, and orange marks life-saving appliances such as lifeboats and liferafts.

Standard workplace signs under ISO 7010 share some colour logic with IMO signs, but the symbol designs themselves are not interchangeable. An ISO 7010 fire extinguisher symbol and an IMO fire extinguisher symbol look different and carry different recognition expectations among seafarers trained to international maritime standards.

The practical implication is that a seafarer trained on IMO symbols may not instantly recognise a standard workplace sign in an emergency, and vice versa. On a vessel where seconds count during a fire or flooding event, that recognition gap is a genuine safety risk. IMO symbols are also designed to remain legible at low viewing angles and in low-light conditions, which reflects the reality of shipboard corridors and stairwells far more directly than symbols designed for factories or offices.

Why do IMO signs require different materials and durability ratings?

IMO signs require materials that can withstand the extreme and constantly changing conditions found on vessels: saltwater exposure, high humidity, wide temperature swings, UV radiation from sun exposure on deck, and the chemical environments found in engine rooms and cargo spaces. Standard workplace signs are not rated for these conditions and will degrade, fade, or fail far sooner in a marine environment.

ISO 15370:2021 sets specific photoluminescent performance thresholds that IMO signs must meet, ensuring they remain visible in darkness or smoke after the vessel’s main lighting fails. This is a critical life-safety function that general workplace photoluminescent signs are not required to match at the same level.

We manufacture our New Generation IMO signs from PVC-free and halogen-free materials, which meet both the environmental requirements of modern shipbuilding programmes and the durability demands of maritime service. Our signs are rated to perform across a temperature range from -40°C to +150°C and carry a service life exceeding 150,000 hours, far beyond what standard industrial signage is designed to deliver.

Where must IMO safety signs be placed on a vessel?

IMO safety signs must be placed at every point where a person needs guidance to reach a muster station, lifeboat, life-saving appliance, or fire-fighting equipment. SOLAS regulations and IMO Resolution A.752(18) define specific placement requirements for escape route signs, fire-fighting equipment markers, and life-saving appliance indicators, covering all passenger and crew areas, corridors, stairwells, and machinery spaces.

Placement is not simply a matter of putting a sign where it looks logical. The regulations require continuous visual guidance along escape routes so that a person in smoke or darkness can follow the signs from any point on the vessel to a place of safety without needing prior knowledge of the ship’s layout. This is why the spacing, mounting height, and photoluminescent performance of each sign are all regulated.

For Low Location Lighting systems such as our 3L-PL™ photoluminescent system and our 3L-EP™ LED system, placement requirements extend to floor-level guidance along escape routes, ensuring visibility even when smoke fills the upper portion of a corridor. These systems complement IMO safety signs and together form a complete escape route marking solution that satisfies SOLAS requirements for both signage and lighting.

What happens if a vessel uses standard workplace signs instead of IMO signs?

A vessel that uses standard workplace signs in place of IMO-compliant marine safety signage will fail port state control inspections and may be detained until deficiencies are corrected. Beyond the regulatory consequence, non-compliant signage creates a genuine safety hazard because the signs may not meet photoluminescent performance requirements, use unfamiliar symbols, or survive the marine environment long enough to remain legible.

Insurance implications are also significant. If an incident occurs on a vessel where non-compliant signage contributed to delayed evacuation or difficulty locating fire-fighting equipment, insurers and investigators will scrutinise the signage records. Demonstrating that a vessel used general workplace signs rather than IMO-approved marine safety signage weakens the operator’s position considerably.

Shipbuilders face their own exposure. Delivering a vessel with non-compliant signage creates liability for defects and can delay handover while remedial work is completed. Specifying IMO-compliant signs from the outset is far less costly than retrofitting after a failed inspection.

When should shipbuilders specify IMO signs versus industrial safety signs?

Shipbuilders should specify IMO safety signs for every area of a vessel that falls under SOLAS regulations, which in practice means all crew accommodation, passenger areas, machinery spaces, escape routes, and any location where fire-fighting or life-saving equipment is stored. Industrial safety signs are appropriate only for shore-based facilities or for areas of a vessel that are explicitly outside the scope of SOLAS, such as certain industrial processing areas on specialised vessels where additional occupational safety signage supplements the mandatory IMO signs.

The clearest decision rule is this: if the space is on a vessel and a person needs to find their way to safety or locate emergency equipment, the sign must be IMO-compliant. If the space is a factory floor, warehouse, or office building, ISO 7010 or the relevant national standard applies instead.

For complex newbuild projects where both vessel areas and integrated industrial systems are involved, the safest approach is to work with a supplier who understands both the maritime and industrial standards and can advise on which applies where. We provide turnkey signage solutions for newbuild projects that cover specification, manufacturing, installation, and post-delivery inspection, ensuring that every sign on board meets the correct standard for its location and function.