Key data
| Stowage factor | 1.25–1.40 m³/t (typical 1.30)44.1–49.4 ft³/t (typical 45.9) |
|---|---|
| Form | Bulk |
| IMSBC group | C Cargoes that neither liquefy nor carry a chemical hazard. |
| Angle of repose | ~28 |
| BCSN | UREA |
ft³/t values are per metric tonne (1 m³/t ≈ 35.31 ft³/t). Stowage factors are indicative — see note below.
Description
Urea is the most widely traded nitrogen fertiliser, shipped as prills or granules to agricultural markets worldwide. At around 1.30 m3/t it is a measurement cargo, filling the holds before the ship reaches her marks. It is inert and easy to carry in principle, with the whole challenge of the cargo being to keep it dry.
Stowage & loading
Holds are presented clean and bone dry, and the free-flowing prills or granules are loaded by conveyor or grab and trimmed level. Because the cargo readily absorbs atmospheric moisture, loading is suspended in rain and hatches are managed to keep humidity out, with the aim of getting a dry cargo into a dry hold and keeping it that way.
Hazards & handling
Urea is strongly hygroscopic: exposed to moisture or humid air it absorbs water and cakes into hard lumps that downgrade the cargo and complicate discharge. It can give off an ammonia odour and is dusty in handling. It is not a safety-of-ship hazard, but it taints and is tainted, so segregation from odour-sensitive and odorous cargoes is observed.
Carriage & discharge
Ventilation is managed to keep humid air out rather than to ventilate the cargo, and the holds are monitored for any ingress of water. Discharge is by grab, and caked cargo at the surface and boundaries may need breaking out. Holds are cleaned of residue, which is itself hygroscopic and can damage a following cargo if left.
Key hazards
- Hygroscopic caking into hard lumps on exposure to moisture or humid air
- Ammonia odour and dust during handling
- Taints and is tainted – requires segregation from sensitive cargoes
Loading precautions
- Load into clean, bone-dry holds and suspend loading in rain
- Manage hatches and ventilation to exclude humid air
- Segregate from odorous and odour-sensitive cargoes
Stowage factors are indicative and vary with grade, origin, moisture and packing. Always verify against the shipper's cargo declaration and the applicable IMSBC Code schedule before fixing or loading. This is general information, not professional or safety advice.