Fire and associated Contingencies

Question 1

Fire triangle: three factors essential to start and sustain a fire:

Answer 1

-fuel -flammable gas or vapour or, alternatively, a solid or liquid capable under certain temperature conditions of giving off a flammable gas or vapour.

-Oxygen

-heat- A heat source with sufficient intensity to initiate the chemical reaction that results in ignition

Question 2

General causes of fire

Answer 2

1. People- human error, attitude e.g throwing cigarette carelessly, poor working system
2. Processes- welding
3. Heating system - portable heaters next to combustible material
4. Lighting and power systems
5. Waste - can be a propagation hazard. Some waste can self ignite
6. Material - under certain temperature some materials can self ignite ink, flax

Question 3

How oil-impregnated cloths self-ignite

Answer 3

The oil starts to oxidise very slowly, but this process gradually speeds up and the pile starts to warm up. The process accelerates until the centre becomes charred. The charred part loses strength so that the weight of material on top causes a small collapse over the charred area. This causes a slight disturbance of the air which may bring sufficient fresh air (containing oxygen) in contact with the charred area to make it self-ignite.

Question 4

Inception hazard

Answer 4

Risk of fire starting

Question 5

Propagation hazard

Answer 5

risk of a fire developing and spreading, involving an assessment of the quantity and nature of the combustible material exposed to loss.

Question 6

Fire load

Answer 6

totality of the combustible elements in buildings, machinery etc. and stock

Question 7

Heat can be transferred from one substance to another by conduction, convection or radiation.

Answer 7

Conduction -two articles with different temperatures come into contact with each other. The heat in the hotter body is transferred into the cooler body, until the level of heat becomes the same

Convection - air currents created in a still atmosphere when a body is introduced whose temperature is higher than that of the atmosphere

Radiation -can occur from any body at a higher temperature than its surroundings. Heat is radiated or ‘lost’ from every surface of the hot body until the air has attained the, by then, reduced temperature of the hot body. However, if a cold body is placed near the hot body but not in contact with it, the cold body will warm up on its surface nearest to the hot body.

Question 8

factors which affect propagation are as follows:

Answer 8

In respect of the building

Fire resistance of floors, ceilings, roof and walls.
Fire resistance of openings (for example, brick enclosed concrete stairs with access by self-closing fire resistant doors).
Fire detection (whether smoke/heat detectors are fitted and working, either as part of a fire alarm system or standing alone).
In respect of each tenant’s portions

Combustibility (of stock, furniture, fixtures/machines and other contents).
Housekeeping standards.
Waste removal.
Storage of flammable liquids.
In respect of the owner/managing agent

Active monitoring of all the above features.

Question 9

methods of controlling inception risks in multi-tenure buildings include

Answer 9

Absolute control of admission of tenants vested in an owner, landlord or managing agent who will operate a strict policy of prohibition of tenants whose occupation(s) are likely to cause fires.
-Frequent inspections by the insurer’s surveyor to identify any likely problems; followed by action by the owner, landlord or managing agent to deal with such problems

Question 10

Methods of preventing or inhibiting the spread of fire include

Answer 10

Fire resisting compartmentation or, if this is not possible, the provision of incombustible partitioning and/or fire resistant linings to walls and partitions, fire resistant ceilings and floor surfaces.

Sprinkler installation(s) designed to protect every room in accordance with insurers’ recommendations.

A combination of an automatic fire alarm system throughout the building, with at least one detector in each room and passageway, and hand-operated fire extinguishers/hose reels

Question 11

Major causes of fire loss

Answer 11

heating and industrial processes

spontaneous combustion
exothermic chemical reaction. The heat builds up until ignition takes place. It usually occurs in an undisturbed mass of organic matter of similar or complementary constituent

smoking

electrical apparatus

static electricity

arson

housekeeping
Poor housekeeping can cause problems by making the inception of a fire more likely
allowing fires to smoulder undetected;
aiding the propagation of a fire once it has started; and
hindering a fire brigade’s efforts in trying to extinguish a fire.

contractors and application of heat

cooking processes.

Question 12

Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation

Answer 12

prevention checklist’ to minimise this risk. It requires such practices as the area of operation being cleared of combustible materials before work commences and the work area being examined an hour after work has finished.

Question 13

Control of Substances Hazardous to Health (COSHH) Regulations 2002

Answer 13

Flammable liquids with a very low flashpoint (such as acetone and benzene) are also subject to self-ignition if stored in a warm atmosphere. It is therefore imperative that such liquids are stored in accordance with the directions in their Control of Substances Hazardous to Health (COSHH) Regulations 2002data sheet