Failure or inappropriate operation of fixed installations
Knowledge and understanding
|Failure or inappropriate operation of fixed installations||
Understand all associated hazard knowledge
Personnel should assume that fixed installations are functioning correctly. If there are indications that fixed installations have failed or are not operating correctly the risk assessment should be adjusted. Fixed installations are designed to perform a specific function and for a range of purposes including:
- Protecting lives
- Protecting escape routes
- Firefighting and fire suppression
- Smoke control and ventilation
- Building protection
- Environmental protection
Systems may already be operating before the fire and rescue service arrives, or they may not be functioning because of poor maintenance, or defective design or installation. If systems are not operating correctly, or if the fire has exceeded its predicted size resulting in the systems being ineffective, the incident may be more hazardous or arduous.
In large or complex buildings, fixed installations such as sprinkler systems may be operating, and may be able to suppress and contain a fire within a compartment while access is gained to the location of the fire and firefighting can commence.
Firefighting tactics may influence the effectiveness of any fixed installations, such as the efficiency of smoke control following gas cooling techniques.
See National Operational Guidance: Fires and firefighting for information on firefighting tactics.
Fixed installations may include:
- Fixed communication systems
- Fire detection systems
- Sprinkler systems
- Smoke control systems including:
- Other fixed installations including:
Some fixed installation systems can present their own hazards – for further information refer to the Building Research Establishment supplementary information. Many types of systems can produce large volumes of water when activated; this may cause damage to the building, its contents or the environment.
The operation of foam fixed installations may obscure vision when trying to ensure that the building fire has been extinguished. The foam may trap heat; when it is removed, the fire could reignite.
Steam systems are rare and generally operate in an airtight environment; activation of the system may be harmful to people in the vicinity. Valves for steam systems, commonly located outside the protected compartment, should be closed off before committing fire and rescue service personnel to the activation area.
Water mist systems can produce large amounts of steam due to the interaction of the water droplets with the heat from the fire.
Dry powder suppression may be toxic or contain irritants; in an environment where moisture is present the powder can turn into an acidic solution.
Due to the low concentration of oxygen, fire and rescue service personnel should avoid working in a reduced oxygen environment without respiratory protective equipment (RPE). This also applies where there is a carbon dioxide system, which may be automatically activated. If the reduced oxygen environment is breached, allowing oxygen in, the fire can grow.
Gaseous systems which use halon alternatives may produce large quantities of corrosive gas, aerosol and liquid as a result of their reaction with the fire. These substances can damage fire and rescue service equipment.