Fire and Fire Protection Flashcards
(9 cards)
In relation to the fire tetrahedron, explain how water and dry chemical powders work to
extinguish fire. (4 marks)
The fire tetrahedron is composed of the elements Oxygen, Heat, Fuel and Chemical chain reaction. A fire is extinguished by removing any one or more of these elements.
Water cools a fire and removes the heat element of the fire tetrahedron
Dry chemical systems extinguish fires by interrupting the combustion process, primarily by smothering the fire. They achieve this by releasing a dry powder (like sodium bicarbonate or monoammonium phosphate) that coats the burning material, preventing it from accessing oxygen. This disrupts the chemical reaction of fire
Describe the process of smouldering combustion. (4 marks)
Smouldering occurs in porous materials producing a solid carbonaceous char. Smouldering has no visible flame and a lower rate of heat release than flaming combustion. Smouldering combustion can change to flaming combustion when sufficient heat has been released or airflow is increased. Smouldering combustion produces smoke and gasses that can combust in the gas phase. Smouldering combustion has weak combustion characteristics and is slow to spread and releases a low amount of heat.
In relation to means of escape, explain what is meant by the following terms:
a) “evacuation time” (2 marks)
b) “travel distance” (2 marks)
Evacuation time refers to the total time taken for all occupants to safely exit a building or reach a place of relative safety after an alarm is raised. This includes the time taken to react to the alarm (pre-movement time) and the actual movement time to reach the exit.
The actual distance travelled from any point in a building to a place of Relative or Ultimate Safety. This
must take account of furniture and internal partitions.
Explain how the use of fire retardants contributes to passive fire protection in a building. (4
marks)
Delay Ignition – Fire retardants increase the ignition temperature of materials, making them less likely to catch fire quickly.
Slow Fire Spread – They inhibit or slow down combustion, reducing the rate at which fire can spread through surfaces such as walls, ceilings, and furnishings.
This question was often answered poorly with some candidates unable to explain that flameretardant coatings will slow down the rate of growth of fire and that this provides time to tackle
a small fire/escape. Good responses set out where fire retardants can be used and how this
can reduce intensity and spread of fire.
In relation to fire resistance, explain the term “insulation” and explain why this is important. (4
marks)
Insulation fire resistance is the ability of a seperating element to resist the transfer of heat from on side to another. This prevents combustion of materials that may be close to a compartment wall on the non-fire side. The temperature on the unexposed side should be limited to a rise 140C on average and 180C at any one point above ambient temperature.
Describe the content of a fire test report and explain the possible limitations of such a report.
(6 marks)
Test Standard and Methodology – Details the standard used (e.g., BS 476, EN 1364, ASTM E119) and the procedures followed during the test.
Sample Description – Provides a full description of the tested item, including materials, dimensions, construction details, and installation method.
Test Results and Performance Ratings – Includes outcomes such as fire resistance rating (in minutes), integrity, insulation, load-bearing capacity, and any failure modes observed during the test.
Limitations
Specific to Test Conditions – The report reflects performance under controlled, laboratory conditions and may not fully represent real-life fire scenarios or environmental factors.
Limited Scope of Application – Results apply only to the exact configuration tested; any changes in material, design, or installation may invalidate the results.
Does Not Guarantee System Performance – A fire test report does not account for maintenance, aging, or interactions with other building elements, which can affect real-world fire resistance.
No ongoing product manufacturing monitoring
Describe steps that building managers can take to ensure that fire protection provisions in
their premises are maintained. (4 marks)
Regular Inspection and Maintenance – Schedule routine checks and servicing of fire protection systems (e.g. alarms, extinguishers, sprinklers, emergency lighting) to ensure they remain operational and compliant.
Fire Risk Assessments – Conduct and review fire risk assessments periodically to identify new hazards and ensure existing fire protection measures are adequate.
Staff Training and Fire Drills – Provide regular fire safety training for staff and conduct fire drills to ensure everyone knows evacuation procedures and how to use fire equipment.
Record Keeping and Compliance – Maintain accurate records of all fire safety checks, maintenance, training, and drills to demonstrate compliance with legal and safety regulations.
a) Explain the purpose and operation of “active fire protection” systems. (4 marks)
b) Explain state how passive fire protection differs from active fire protection. (2 marks)
The purpose of active fire protection systems is to detect a fire and alert the occupants of a building allowing early evacuation. Sprinkler systems can extinguish a fire or reduce its severity giving time for fire fighting services to arrive. Smoke control systems are activated on detection of a fire.
Active fire suppression systems operate by detection of smoke and heat detectors or manual alert points. The signal from these detection systems operates alarms, sprinklers, smoke control systems fire curtains and fire door openers/closers.
Passive fire protection differs from active fire protection as it is built into the fabric of a building and does not require energisation to operate. The purpose of passive fire protection is to contain a fire within a compartment for a period of time.
Explain how signage can be used to improve fire safety in a building. (4 marks)
Signage can be used to improve fire safety by:
Prohibition signs – prevent actions that can cause a fire
Escape route, escape equipment and assembly point signage - aids the safe evacuation of a building
Mandatory Instructions, for example fire door keep shut – helps to control the spread of fire
Firefighting equipment locations – Identify the location of portable extinguishers and fire hose reels
