Unit GC 2 – Controlling workplace hazards Element 6: Fire safety

Question 1

The principle of the fire triangle

Answer 1

Fire requires 3 elements: a source of heat (or ignition); fuel (something that will burn) and oxygen. If those elements do not come together at the right time in the right amount than fire will happen. If one of those elements is removed from a fire then it will go out.

Question 2

Identify 5 common sources of ignition and fuel in the workplace

Answer 2

Ignition Sources

Smoking materials 
Grinding operations 
Boilers 
Faulty electrical systems 
Hot work (welding) 

Fuel Sources

Furniture 
Cardboard packaging 
Paper 
Textiles 
Chemicals

Question 3

Common sources of oxygen in the workplace

Answer 3

• The air Bottled industrial or medical oxygen
• From oxidising agents
• From air conditioning and ventilation systems
• Compressors and compressed air systems

Question 4

Complete the table to show the types of fuel involved.

Answer 4

Class / Type of fuel

A - Solids (paper, wood, cardboard, textiles)

B - Liquids (petrol, paint, solvents)

C - Gas (Butane, LPG)

D - Metal (Aluminium, magnesium, steel)

F - Cooking fat and oil

Question 5

The principle of fire and heat spread by:

Answer 5

Convection

Hot air rises in currents causing the build up of hot and unburnt gases under ceilings etc. and allows fire and smoke to spread from one floor to another by stairwells, lift shafts and other voids.

Conduction

Heat travels through solid material and can transfer heat through steel structures to another part of a building where, if there is combustible material it will ignite.

Radiation

Heat is radiated through the air from a source heating the air and materials away from the fire. If the materials are combustible and the heat sufficient then fire will spread.

Direct Burning

If the burning material is in direct contact with other fuel that fuel heats up and eventually ignites.

Question 6

Identify 6 common causes of fire in the workplace.

Answer 6

1. Discarded smoking materials
2. Equipment overheating
3. Faulty electrics causing arcing / heating
4. Grinding operations (sparks) near flammable vapours / materials
5. Arson
6. Discarded oily rags in waste bins

Question 7

The requirements for a fire risk assessment

Answer 7

Steps to be taken when carrying out a fire risk assessment.

Step 1 – Identify the hazards looking for sources of heat, fuel and oxygen.
Step 2 – Identify those at risk including special groups such as disabled and infirm
Step 3 – Evaluate the risks taking into account:

• Fire prevention measures
• Fire protection measures
• Fire precaution measures
• Management measures such as emergency plans and training in place at the time

Step 4 – Record significant findings including an action plan for improvement
Step 5 – Review after significant change or passage of time.

Question 8

Measures that may be taken to reduce the possibility of fire in the workplace.

Answer 8

Fire prevention is achieved by keeping fuel and heat separate where possible.

This can be achieved by:

 Keeping the amount of flammable substances to a minimum
 Use of permits to work for hot work
 Ensure electrical equipment is properly maintained
 Good housekeeping to prevent a build-up of rubbish
 Have a planned maintenance regime for machinery
 Control smoking where it is not forbidden
 Ensure storage facilities for flammable materials are suitable i.e.

• Secure
• Away from main work area
• Allows for segregation of empty and full containers
• Properly marked with appropriate signage

Question 9

Outline the main requirements for the storage of small quantities of flammable liquids.

Answer 9

• Keep amounts on shop floor to a minimum (only what is being used)
• For materials with flashpoint above 32°C - max 250 litres may be stored in workroom, for materials with flashpoint below 32°C – max 50 litres may be stored in workroom
• Suitable storage cabinets (fire-proof)
• Keep lids on containers when not being used

Question 10

With reference to fire spread, explain what is meant by compartmentation and how it can be achieved.

Answer 10

Compartmentation can be described as the division of the building into discrete zones in order to prevent, or at least retard, the spread of smoke and fire.

It can be achieved by using fire rated fire doors and by the use of fire retardant materials in the build and decoration of the premises.

Question 11

3 common types of detector that may be used as part of a fire fighting system.

Answer 11

1. Smoke detectors
2. Heat detectors
3. Flame detectors

Question 12

Requirements for siting of fire extinguishers

Answer 12

Located so they are:

• Clearly visible
• On escape routes
• At a manageable height
• Protected from potential sources of damage e.g. weather
• Their location should be signed

Maintenance requirements for fire extinguishers

They should be regularly inspected to ensure that:

 They have not been interfered with
 That they have not been discharged
 That there is no sign of obvious damage
 They should be examined annually by a competent person to:

• Check the integrity of the extinguisher
• Renew any damaged or faulty parts
• Ensure all labels are legible

Question 13

Complete the following table for fire extinguishers:

Colour / Content / Class of fire most suitable for / Leg of triangle removed

Answer 13

Red - Water - A - Heat (Ignition)

Cream / Beige - Foam - A, B - Heat (Ignition) Oxygen

Blue - Dry powder - A, B, C - (Electrical) Oxygen

Black - Carbon Dioxide - B - (Electrical) - Oxygen

Yellow - Wet chemical - Cooking oil fires - Oxygen

Question 14

Identify 6 issues that should be considered when establishing a safe means of escape.

Answer 14

1. Travel distances
2. Aisle widths
3. Number of doors
4. Signs
5. Lighting and emergency lighting
6. Vulnerable groups

Question 15

Emergency fire procedures

Answer 15

To identify the action to be taken by individuals in the case of an emergency.

Question 16

Fire marshals

Answer 16

These are trained people who help to ensure a n effective response to an emergency. They may have responsibility for particular areas, helping people and making sure the area is clear.

Question 17

Fire drills and roll calls

Answer 17

Fire drills are designed to practice the emergency procedures and identify any weaknesses in the procedure. Roll calls help to establish whether everybody has been accounted for following an evacuation.

Question 18

Identify issues that should be considered for the safe evacuation of infirm and disabled people in an emergency.

Answer 18

• Disabled people should have a safe means of escape in the event of fire. Determine which areas of the building are used by disabled people.
• A Personal Fire Evacuation Plan should be drawn up for every disabled person or group of disabled people in the building.
• A sufficient number of people should be trained in advance in giving assistance to disabled people.
• Make arrangements to ensure that the presence of a disabled person is known by those who would give assistance.
• Disabled people should not use any part of a building where it would be difficult for them, even with help, to escape in the event of fire.
• Use evac-chairs or designated lifts to get to ground level.
• Have low level signage and lighting where necessary
• Have door operating controls at a level suitable for wheel chair users.

Question 19

Outline the main requirements for a safe means of escape from a building in the event of fire.

Answer 19

Requirements such as the provision of at least two routes in essentially opposite directions with the number of routes required dependent on the number of employees and their location in the premises; the travel distances involved being as short as possible to enable a quick escape with all escape routes leading to a final exit, the door of which should open quickly and easily and preferably outwards and lead to a safe place and an arranged assembly point; the protection of fire exit routes with fire resistant materials and the fitting of self closing fire doors along corridors and protected routes; the provision of adequate signage for and emergency lighting along exit routes; the introduction of procedures for disabled persons including the provision of safe havens; the location of fire fighting equipment along exit routes; the provision of means for raising the alarm which should have sufficient call points and be audible throughout the premises and the need to introduce emergency procedures such as fire drills and the appointment of responsible persons as fire marshals.

Question 20

Principles of fire

Answer 20

Fire is a chemical reaction known as combustion. It occurs when fuel, oxygen and an ignition (heat) source are brought together. The three elements are commonly referred to as the fire triangle. The important factor to remember, as represented by the fire triangle, is that you need all three elements to be present to be able to start and maintain a fire.

Sources of ignition:

	Cigarettes/matches; 
	Naked flames; 
	Presence of electrical/gas/oil heaters; 
	Hot processes such as welding: 
	Machinery operations; 
	Static electricity; 
	Cooking. 

Sources of fuel:

	Flammable liquid products and solvents; 
	Plastics, rubber and foam; 
	Wood and paper; 
	Flammable gases; 
	Furniture; 
	Loose packaging material; 
	Waste materials. 

Sources of oxygen

Air is the main source of oxygen, provided by two forms of ventilation:

 Natural airflow through openings
 Air-conditioning systems

Additional sources:

 Oxidising chemicals
 Oxygen supplies from cylinders/piped systems

Question 21

Identify four common ignition sources that may lead to a fire in the workplace.

Answer 21

 Presence of electrical/gas/oil heaters;
 Hot processes such as welding:
 Machinery operations;
 Cooking.

Question 22

Identify the 5 stages of a fire risk assessment.

Answer 22

Step 1 - Identify the fire hazards
Step 2 - Identify people at risk
Step 3 - Evaluate, remove, reduce and protect from risk
Step 4 - Record, plan, inform, instruct and train.
Step 5 - Review

Question 23

Outline the factors that should be considered when providing a means of escape in a workplace.

Answer 23

When assessing the adequacy of the means of escape the employer must take into account:
 The size of the workplace, its construction, layout, contents and the number and width of the available escape routes;
 The workplace activity, where people may be situated in the workplace and what they may be doing when a fire occurs;
 The number of people who may be present and their familiarity with the workplace;
 The needs of vulnerable groups of people during the evacuation;
 The level of lighting and emergency lighting available;
 The number of exits available; • the travel distances to a place of safety;
 The signage in place.

Question 24

Outline six structural measures that can help to prevent the spread of fire and smoke.

Answer 24

1. Steel support structures – steel support structures are strong but are good conductors of heat and may lose structural strength and collapse in intense heat conditions.
2. Brick built structure – bricks have an excellent ability to cope with excess temperatures and so brick structures can behave well in fire conditions.
3. Stone built or clad structures – stone will often crack in fire conditions which may increase the likelihood of structural failure.
4. Timber- most woods are combustible, although thick timber supports will carbonise on the outside during a fire and they are unlikely to completely fail in fire conditions.
5. Breeze blocks – the building blocks are highly resistant to fire and breeze block structures are unlikely to collapse in fire conditions.
6. Glass – most glass will shatter in high temperature conditions.

Question 25

By applying the following five principles you will be well on the way to making sure that you are working safely with flammable substances. Think V.I.C.E.S and keep a strong grip on your workplace safety.

Answer 25

Ventilation
Is there plenty of fresh air where flammable liquids or gases are stored and used? Good ventilation will mean that any vapour’s given off from a spill, leak, or release from any process, will be rapidly dispersed.

Ignition
Have all the obvious ignition sources been removed from the storage and handling areas? Ignition sources can be very varied and they include sparks from electrical equipment or welding and cutting tools, hot surfaces, open flames from heating equipment, smoking materials etc.

Containment
Are your flammable substances kept in suitable containers? If you have a spill will it be contained and prevented from spreading to other parts of the working area? Use of lidded containers and spillage catchment trays, for example, can help to prevent spillages spreading.

Exchange
Can you exchange a flammable substance for a less flammable one? Can you eliminate flammable substances from the process altogether? You may be able to think of other ways of carrying out the job more safely.

Separation

Question 26

Other forms of fire fighting equipment:

Answer 26

• Fire Blankets - are often used in small kitchens to smother a small fire that may occur in the area.
• Hose reels - are very effective against Class A fires, they are located near fire exits and stairways. Hose reels are easily operated in the the event of a fire.
• Automatic sprinklers - are activated by fire detectors and can reduce fire spread due to prompt response however the sensitive detection system or intentional activation through malicious behavior may result in false activation.