Loss of Containment (LoC) scenarios

Loss of containment

Loss of containment (LoC) scenarios refer to situations where hazardous materials unintentionally escape from their intended confinement, which can occur through leaks, spills, ruptures, or overflows. These incidents can lead to fires, explosions, or toxic exposure, posing significant risks to health, safety, and the environment.

LoC scenarios categories

The approach to identifying the consequences of LoC scenarios is primarily based on the physical state of the material being released (liquid, gas, or liquefied gas). Each state presents distinct challenges and risks, depending on factors such as pressure, temperature, and chemical properties. This categorisation is not only important for predicting the behaviour of the released material and exposure risks but also for developing separate guidelines, regulations and containment strategies.

Examples of behaviour and risks per physical state category

Gas

• Disperse rapidly into the surrounding environment.

• Poses health risks of inhalation for workers and nearby populations.

• Presents potential for flammability or explosive atmospheres.

• Example: leaks or ruptures from pressurised gas cylinders or pipelines carrying natural gas.

Liquid

• Spills or leaks spread over land or waterways.

• Poses risks of environmental contamination, including soil and water pollution.

• Presents potential health hazards from direct contact or ingestion and flammability hazards.

• Example: leaks from storage tanks containing chemicals or petroleum products such as gasoline or bitumen.

Liquefied Gas

• Results in flashing (rapid vaporisation) and expansion.

• Poses risks of overpressure, fire, or explosion.

• Example: leaks or ruptures of storage tanks containing liquefied natural gas (LNG) or liquefied petroleum gas (LPG) or refrigerated cryogenic ammonia.

Conclusion

LoC scenarios are critical points of focus in process safety management, as understanding and preventing them is essential for maintaining operational integrity and safeguarding against accidents.