| Grade | Main quality constraints | Typical blend | Class |
UK Light Fuel Oil (SG) | Visc | 5.0-8.2 cSt | E |
| Sulphur | 1 wt% max | ||
| Pour | 0 max (W) / 6 max (S) | ||
| UK Medium Fuel Oil (SG) | Visc | 13-20 cSt | F |
| Sulphur | 3.5 wt% max | ||
| Pour | 24 max | ||
| UK Medium Fuel Oil | Visc | 13-20 cSt | F |
| (10S) | Sulphur | 1 wt% max | |
| Pour | 24 max | ||
| UK Heavy Fuel Oil (SG) | Visc | 25-40 cSt | G |
| Sulphur | 3.5 wt% max | ||
| Pour | 30 max | ||
| UK Heavy Fuel Oil | Visc | 20-40 cSt | G |
| (10S) | Sulphur | 1 wt% max | |
| Pour | 30 max | ||
| FR FO 1% | Visc | 9.5cSt min @20degC, 40cSt max @ 100degC | |
| Sulphur | 1 wt% max | ||
| FR FO 4% | Visc | 9.5cSt min @20degC, 40cSt max @ 100degC | |
| Sulphur | 4 wt% max | ||
| BUNKERS | |||
| FR IF180 | Visc at 50 degC | 140-180 cSt | |
| Sulphur | 1.5 or 4% max | ||
| FR IF 380 | Visc at 50 degC | 300-380 cSt | |
| Sulphur | 1.5 or 4% max | ||
| FR IF 500 | Visc at 50 degC | 500 cSt max | |
| Sulphur | 1.5 or 4% max |