Photoluminescent Material Class Comparison - IMO
IMO safety signs must remain visible in low-light and blackout conditions. While there is no legal requirement for a specific class, industry best practice — particularly for SOLAS-regulated vessels — recommends Class C or higher performance.
| Class | Initial Brightness (after 10 mins) |
Typical Decay Time | Suitable For | IMO Marine Use |
|---|---|---|---|---|
| Class B | 20–50 mcd/m² | ~300 minutes | Low-traffic, low-risk areas | ⚠️ Not recommended (underperforms for escape signage) |
| Class C | 50–150 mcd/m² | ~600 minutes | Commercial vessels, escape routes | ✅ Recommended minimum |
| Class D+ | 150+ mcd/m² | ~900–1200 minutes | Critical escape paths, high-traffic areas | ✅ Ideal for SOLAS compliance |
Note: All IMO signs should also comply with IMO Resolution A.1116(30) for symbol layout, design, and legibility.
For maximum compliance and safety assurance, we recommend only using signs manufactured with Class C photoluminescent material or above.