1. FIRE SAFETY

2. Fire Science
Fire Science is the science of preventing and mitigating the adverse effects of fire.
Prevention decreases the likelihood that an emergency will occur.
Mitigation actions are steps that eliminate or reduce the loss of life or property damage.
Fire-science programs cover all aspects of fire prevention, control, response and post-incident activities.

3. Fire Prevention

4. Definition of Fire
Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products
Usually fire occurs when a source of heat comes in contact with combustible material in presence of air.

5. Three (3) elements are required for combustion to occur :
Fire Elements
Three (3) elements are required for combustion to occur :
Fuel – to vapourise and burn
• Oxygen – to combine with fuel vapour
• Heat – to raise the temperature of the fuel vapour to its ignition temperature

6. Fire triangle Fire triangle or combustion triangle is a simple model
for understanding the
ingredients necessary for
occurrence of a fire.

7. Fire triangle…..
The triangle illustrates a fire requires three elements : heat,fuel and oxygen.
The fire is prevented or extinguished by removing any one of them. A fire naturally occurs when elements are combined in right mixture.

8. Fire triangle…….
Fire cannot begin if either heat or oxygen is insufficient.
When oxygen-fuel mixture is in right proportion and the heat source is of adequate intensity to initiate ignition of oxygen fuel mixture, fire will occur.

9. Fire tetrahedron
Fire tetrahedron is an addition to the fire triangle. It adds the requirement for the presence of the chemical reaction which is the process of fire.

10. Combustion Process….
The occurrence of combustion is associated with a spontaneous acceleration of the rate of oxidation reaction in the system. The process of spontaneous acceleration of the rate of oxidation turning into combustion can be attributed to three basic processes:--
-- heat
-- chain
-- heat-chain reaction

11. Combustion Process……
The heat theory explains the autoignition by the activation of oxidation and increased chemical reaction due to heat.
The chain theory states self- ignition to the branching of the chains of chemical reaction.
In practice, combustion process occurs by heat-chain mechanism.

12. Combustion of gases
Fire and explosion hazards from gases are determined by :
the concentration limits of ignition (more commonly known as the explosive range),
ii) ignition source intensity,
iii) combustion temperature and
iv) rate of flame spreading.

13. Combustion of gases….
A gaseous combustible mixture will burn only if it contains the right proportion of fuel.
The lowest amount of fuel at which combustion may take place is known as the lower concentration limit of the explosive range.
The highest concentration of fuel in a combustible mixture at which combustion may still take place is called the upper concentration limit of the explosive range.
The range of concentration is called the explosive range (or range of ignition).

14. Combustion of gases…….
The minimum intensity of ignition is the lowest value of the electric discharge spark intensity sufficient to ignite the most rapidly ignitable mixture of the given gas, vapor or dust with air.
A gas is termed combustible if its mixture with air ignites at temperatures below 55°C.
Gases such as acetylene, hydrogen and hydrogen sulfide which have a wide explosive range, low lower limit of the explosive range, low ignition intensity and high flame speed are the most dangerous.

15. Combustion of liquids
All combustible liquids ,are known to evaporate and
combustion takes place only in the vapor phase over the liquid surface.
The amount of vapor formed depends on the temperature of the liquid.
Combustion will take place only when the concentration of vapor reaches the explosive range limit.

16. Combustion of liquids…….
The lowest liquid temperature at which the proportion of vapors in air is sufficient for the mixture to ignite in the presence of an open flame heat source without consequent steady state combustion is known as the flash temperature (or flash point).
A liquid is termed combustible if it keeps burning when ignited and after the ignition source has been withdrawn.
The flash point of such liquids is not above 61°C (in closed crucible) or not above 66°C (in an open crucible).

17. Combustion of liquids…….
The flash point is known as the temperature at which a liquid become extremely dangerous as regards fires. It has, therefore, been adopted for classifying combustible liquids by their hazard of fire.
Fire and explosion risks involved in liquids can be characterized also by the temperature limits of the explosive range of their vapors.

18. Combustion of liquids…….
The temperature of a liquid at which the concentration of its saturated vapour in a limited air volume is capable of igniting in the presence of a source of ignition (heat) is known as the lower temperature limit of the explosive range.
The temperature of the liquid at which the concentration of its saturated vapors in a limited air volume is still capable of igniting in the presence of an ignition source is called the upper temperature limit of the explosive range.

19. Combustion of dusts
Dust, by fire hazard, is many times more dangerous than the material (product) from which it is formed. This is explained by a greater specific surface of dust particles as compared with that of a solid body.
The properties of pulverized material are quite different from those of the same material in a solid state. The oxidation surface is so large that the heat losses into the environment are minimum and the dust becomes liable to self-ignition (dust of aluminum, iron, brass).

20. Combustion of dusts…….
Like the combustible air, gas and air vapor mixtures, dusts may explode when their concentrations in the air reaches the explosive range.
The lower explosive limit of dusts is most important characteristic because dust concentrations corresponding to this limit may be formed both inside the machine treating solid materials, and almost everywhere in production premises

21. Combustion of dusts……..
Dust is said to be more dangerous, the lower its lower explosive limit and the lower its auto - ignition temperature.
The risk of explosion are high with dusts whose lower concentration explosive limit is below 65g/m3 (Pulverized sulfur, sugar, flour).

22. Fire Behaviour
Fires behave differently. Some burn slowly and evenly; others are extremely hot, burning violently and quickly.
Different fires have different coloured flames. Some fires start easily; others don’t. Some fires produce deadly gases and smoke which may be the cause of death if not ventilated

23. Fire Behaviour……
The behaviour of the fire often depends on the fuel. Other factors or variables may include where the fuel is situated and how near it is to other fuels, the weather (especially wind and relative humidity), oxygen concentration.
Different fuels catch fire at different temperatures. It takes a certain amount of heat energy to change any particular material into a gas (if it is not already). Then it takes more heat energy to trigger the reaction with oxygen

24. Fire Behaviour……
The amount of heat produced depends on the molecules that make up the fuel. The most flammable fuels are hydrocarbons (contain carbon and hydrogen) that recombine with oxygen quite easily to form carbon dioxide, water and other gases.
Size or surface area of fuel determine how quickly a fuel catches fire and burns For example, large pieces of wood take a lot longer to absorb heat energy to ignition temperature. Thin wood catches fire easily because it heats up easily

25. Fire Behaviour……
The bigger the area of the surface of the fuel, the more oxygen molecules can collide with the surface. The more oxygen molecules that collide per second with the fuel, the faster the combustion reaction is.
A powder has the largest surface area and will have the fastest reaction rate

26. Fire Behaviour……
Amount of fuel available to burn is known as the fuel load. The bigger the fuel load, the more intense the fire will be in terms of heat energy output.
Oxygen availability will affect the rate of burning. A low concentration of oxygen will slow the burning right down.

27. Fire Behaviour……
An example of dangerous fire behaviour that can occur in a situation where there is a low concentration of oxygen is called backdraught (an explosive surge in a fire produced by the sudden mixing of air with other combustible gases).
This is when an enclosed fire has used up most of the oxygen and is just smouldering. If there is a sudden influx of oxygen (like someone opening a door or window), the fire will immediately explode into flame

28. Fire Behaviour……
Relative Humidity reflects the amount of moisture in the air. If relative humidity is low, it will contribute to the drying of fuels. If it is high, fuels will absorb moisture from the air, making ignition more difficult.
Wind is a major factor in determining fire spread. Wind affects the rate of oxygen supply to the burning fuel (controlling combustion) and it tilts the flame forward so that unburned fuel receives energy by radiation and convection at an increased speed. Wind can also dry out the fuel

29. Common gases and smoke
The particular gases produced by a fire depend mainly on the fuel.
The most common hazardous gases are carbon dioxide (CO2), the product of complete combustion, and carbon monoxide (CO), the product of incomplete combustion.

30. Common gases and smoke……..
Carbon monoxide is the more dangerous of the two. When air mixed with carbon monoxide is inhaled, the blood absorbs the CO.
The result is an oxygen deficiency in the brain and body. Exposure to a 1.3% concentration of CO will cause unconsciousness in two or three breaths and death in a few minutes.

31. Common gases and smoke……..
Carbon dioxide works on the respiratory system. CO2 concentrations in the air reduce the amount of oxygen that is absorbed in the lungs. The body responds with rapid and deep breathing, which is a signal that the respiratory system is not receiving sufficient oxygen.
When the oxygen content of air drops from its normal level of 21% to about 15%, human muscular control is reduced. At 10% to 14% oxygen in air, fatigue sets in. Unconsciousness usually results from oxygen concentrations below 10%.

32. Common gases and smoke……..
Depending upon the fuel source, there may be several other gases generated by a fire that are of equal concern. e.g.
i) Hydrogen cyanide (HCN) is produced when nylon, wool etc. are involved in fire. Hydrogen cyanide arrest the activity of all forms of living cells of body muscles and nerves.
ii) Hydrogen chloride (HCl) is produced when polyvinyl chloride (PVC) is decomposed at fires. If inhaled, HCl will damage the upper respiratory tract and lead to asphyxiation or death.

33. Common gases and smoke……..
Smoke is a visible product of fire that adds to the problem of breathing. It is made up of carbon and other unburned substances in the form of suspended particles.
It also carries the vapors of water, acids and other chemicals, which can be poisonous or irritating when inhaled

34. Smoke detector
A smoke detector is a device that detects smoke, typically as an indicator of fire. Smoke detectors are typically housed in a disk-shaped plastic enclosure about 150 millimetres (6 in) in diameter and 25 millimetres (1 in) thick.
Most smoke detectors work either by optical detection (photoelectric) or by physical process (ionization), while others use both detection methods to increase sensitivity to smoke.

35. Smoke detector……..
All smoke detectors consist of two basic part : a sensor to sense the smoke and a very loud electronic horn to wake people up. Smoke detectors can run off of a 9-volt battery or 120-volt house current.
Test requirements for smoke detectors fall broadly into two categories - Functional (or Operational) Testing and Calibration (or Sensitivity) Testing. Functional checking is accomplished by introducing a smoke, from the protected area through the vents of a detector to the sensor (s). Sensitivity testing confirms whether the detector’s performance is within the acceptable parameters.

36. Smoke detector……..
While regular testing is essential in making sure that the
smoke detector is working properly, regular maintenance is a
very good idea as well to ensue that no dust, hair or fiber
particles are hiding the grates in the smoke detector,
preventing the detector to detect a problem, or even cause
damage to the interior workings.

37. Smoke Exhaust System
Smoke Exhaust is used to remove smoke from buildings to enable emergency evacuation as well as improved firefighting.
Smoke Exhaust System is a mechanical or gravity system intended to convey smoke from one portion of a building to the outdoors and usually includes a venting system, as well as exhaust fans.

38. Fire door
Fire door is a door with a fire-resistance rating (the duration for which a fire protection system can withstand a standard fire resistance test) and used as part of a fire protection system to reduce the spread of fire or smoke between compartments and to enable safe egress from a building.

39. Fire doors may be made of a combination of materials, such as:
i) timber
ii) steel
iii) gypsum (calcium sulphate )
iv) vermiculite (natural mineral that expands with the application of heat)
V) glass sections
Fire doors maintain its structural integrity for a period of time in the event of a fire.

40. Exit sign
An exit sign is a device in a building denoting the location of the emergency exit, guiding people to the closest exit in case emergency including fire.. Most relevant codes (fire, building, health or safety) require exit signs to be permanently lit.
Exit signs shall be preferably in pictogram form, with text supplement.

41. Exit sign…….
Since visibility may be reduced in a fire, due to smoke or failure of electric lighting, the sign is often permanently illuminated, usually by :
i) electric light, with the building's emergency lighting circuits providing back-up power from a UPS and/or a generator in case normal power fails , or
ii) electric light, with a local rechargeable power source

42. Emergency lighting
An emergency light is a battery-backed lighting device that comes on automatically when a building experiences a power failure as a result of a fire or a power cut to avoid darkness and a possible danger to occupants either throuh physical danger or panic.
The system normally used is lead acid batteries to store a full 120-volt charge.
Electrical devices are used to switch on the lights and battery supply in the event of a power failure automatically

43. Treatment following inhalation of gases and smoke
Treatment varies with the severity of the damage caused.
The primary focus of treatment is to maintain an open airway and provide an adequate level of oxygen.
If the airway is open and stable, the individual may be given high-flow humidified 100 percent oxygen by mask.
If swelling of the airway tissues is closing off the airway, the person may require the insertion of a breathing tube to artificially maintain an open airway.

44. Treatment following inhalation of gases and smoke..
Oxygen is often the only medication necessary. However, people who have a cough with wheezing (bronchospasm), indicating that the bronchial airways are narrowed or blocked, may be given a bronchodilator to relax the muscles and increase ventilation
Hyperbaric oxygen therapy ( treatment of the entire body with 100-percent oxygen at greater than normal atmospheric pressures ) may be used to treat smoke inhalation, resulting in severe carbon monoxide or cyanide poisoning. This treatment requires a special chamber in which the person receives pure oxygen at three times the normal atmospheric pressure, thus receiving more oxygen faster to overcome loss of consciousness and other associated illnesses.

45. Treatment following inhalation of gases and smoke..
There are also antidotes for specific poisonous gases in the blood e.g. hydroxocobalamin  against hydrogen cyanide, dosage is dependent upon the level indicated by blood tests. Oxygen works as an antidote against carbon monoxide as it increases the removal of carbon monoxide from hemoglobin, in turn providing the body with normal levels of oxygen.
Carbon dioxide is an asphyxiant gas and not classified as toxic or harmful. There is no antidote to be administered to counteract the effects of inhalation of hydrogen chloride. In case of severe inhalation exposure, humidified supplemental oxygen should be administered.

46. Extinguishment Theory
The extinguishment of fire is based on an interruption of one or more of the essential elements in the combustion process.  
With flaming combustion the fire may be extinguished by reducing temperature, eliminating fuel or oxygen, or by stopping the chemical chain reaction. 
 If a fire is in the smoldering mode of combustion, only three extinguishment options exist  reduction of temperature, elimination of fuel or oxygen

47. Extinguishment Theory…….
Extinguishment by Temperature Reduction
One of the most common methods of extinguishment is by cooling with water. 
  The process of extinguishment by cooling is dependent on cooling the fuel to a point where it does not produce sufficient vapour to burn.  If we look at fuel types and vapour production, we find that solid fuels and liquid fuels with high flash points can be extinguished by cooling.   
Low flashpoint liquids and flammable gases cannot be extinguished by cooling with water as vapour production cannot be sufficiently reduced.

48. Extinguishment Theory…….
Extinguishment by Fuel Removal
In some cases, a fire is effectively extinguished by removing the fuel source. 
 This may be accomplished by stopping the flow of liquid or gaseous fuel or by removing solid fuel in the path of the fire. 

49. Extinguishment Theory…….
Extinguishment by Oxygen Dilution
The method of extinguishment by oxygen dilution is the reduction of the oxygen concentration to the fire area. 
 This can be accomplished by introducing an inert gas into the fire or by separating the oxygen from the fuel.
Carbon dioxide or nitrogen, are the two most common extinguishing agents.

50. Extinguishment Theory…….
Extinguishment by Chemical flame Inhibition
Some extinguishing agents, such as dry chemicals interrupt the flame producing chemical reaction, resulting in rapid extinguishment.  
This method of extinguishment is effective only on gas and liquid fuels as they cannot burn in the smoldering mode of combustion.

51. Classification of fire and their distinguishing agent
Fuel Source
Class of Fire
Type of Extinguisher (Extinguishing Agent)
Ordinary combustibles (e.g. trash, wood, paper, cloth) A
Water; chemical foam; dry chemical
Flammable liquids (e.g. oils, grease, tar, gasoline, paints, thinners) B
Carbon dioxide (CO2); halon*; dry chemical; aqueous film forming foam (AFFF)
Electricity  (e.g. live electrical equipment) C
CO2; halon; dry chemical
Combustible metals (e.g. magnesium, titanium) D
Dry powder (suitable for the specific combustible metal involved)
Combustible Cooking (e.g. cooking oils; animal fats, vegetable fats) K
Wet chemical (Potassium acetate based)

52. Classification of fire and their distinguishing agent..
Halon(Chlorodifluorobromomethane)extinguishers are no longer made but some may still be in use. Dangerous gases are formed when halon is used to put out fires.
Wear proper respiratory equipment, particularly in enclosed spaces. After use, do not allow anyone to enter the area until it has been well ventilated.

53. Fixed Fire protection Equipments
Fixed in-plant fire protection equipment includes water equipment such as sprinklers, hydrants.
Sprinklers :
A fire sprinkler discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Each sprinkler is held closed by either a heat-sensitive glass bulb or a metal link held together with fusible alloy such as lead, tin, cadmium, zinc.
The glass bulb or link applies pressure to a cap which acts as a plug and prevents water from flowing until the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler.

54. Fixed Fire protection Equipments…..
Since each sprinkler head is automatically triggered by fire-specific temperature, just one or two sprinklers can quickly extinguish and / or contain a fire to the room where it started and cause little property damage.
Inspection and servicing of fire sprinklers shall be carried out by highly trained technician as per manufacturer’s recommendation.

55. Fixed Fire protection Equipments…..
Hydrant :
A fire hydrant is an above-ground connection that provides access to a water supply for the purpose of fighting fires. Every hydrant has one or more outlets to which a fire hose may be connected. It also have one or more valves to regulate the water flow.
In order to provide sufficient water for firefighting, hydrants are sized to provide a minimum flowrate of about 945 liters per minute.

56. Fixed Fire protection Equipments…..
Fire hydrants shall be maintained through flushing, inspection, lubricating, cleaning, and painting on a semi annual basis or as required. The main reason for hydrant maintenance is to insure that they will function correctly at times of fire.
Fire engines hold a maximum of 5-6 minutes of water available for fire attack.  An improperly or non-functioning hydrant could cause a fire engine to run out of water.

57. Fixed Fire protection Equipments…..
A fire hose is a high-pressure hose used to carry water to a fire to extinguish it. Outdoors, it is attached either to a fire engine or a fire hydrant. Indoors, it can be permanently attached to a building's standpipe or plumbing system.
The usual working pressure of a fire hose can vary between 8 and 20 bar (116 and 290 psi), while its bursting pressure can be up to 83 bar (1,204 psi).
After use, a fire hose is usually hung to dry as standing water that remains in a hose for an extended period of time can deteriorate the material and render it unreliable or unusable.

58. Electrical Fire Hazards and Control Measures
Electricity can be the source of heat to ignite flammable materials. Current flow in a conductor produces heat because of the conductor’s resistance to the flow of electricity. Increased heat in electrical conductors can be expected when :
• The wire size is too small to carry the current (trying to run an electric motor on a lamp cord)
• The electrical load is too great
• The electrical connections are loose, and increased resistance develops.

59. Electrical Fire Hazards and Control Measures…
Common protective devices are :
• Fuses
• Circuit breakers
• Ground fault circuit interrupters (GFCIs)
Fuses are either a screw-in or cartridge type. A metal strip melts when the circuit is overloaded and interrupts the circuit. The fuse must be replaced. The “main” power switch should be shut -off before changing fuses.

60. Electrical Fire Hazards and Control Measures…
Circuit breakers look like switches. When a bi-metal strip (two different metals) is heated from electrical overload, the metal becomes distorted in shape and causes the circuit breaker to cut out. The overload problem must be corrected and the switch returned to the on position.
Ground Fault Circuit Interrupters look like a circuit breaker. These GFCI devices break the circuit in microseconds when a difference in current is sensed. These devices are used where moisture is found e.g. milk room, kitchen etc.

61. Fire Fighting Water Requirement
The required fire fighting water flow rate is given by :
Where, Qf the heat release rate of the fire (kW),
ηab is the cooling efficiency, i.e., the efficiency of the water in absorbing the energy from the fire (0≤ η ≤ 1),
and
QW is the rate at which energy can theoretically be absorbed by the water (2605 kW/L/s).

62. Fire Fighting Water Requirement…….
The cooling efficiency is a factor used to account for the fact that not all of the water applied to a fire will be converted to steam.
The value of QW is based on the fact that one litre of water will absorb MJ of energy when it is heated from 0°C to steam at 100°C.

63. General Principles of Firefighting
CONCEPT 1
When sufficient manpower isn’t available to effect both rescue and extinguishment at the same time, rescue must be given priority.
CONCEPT 2
When you don’t have sufficient manpower to perform all of the needed tasks, first perform those that protect the greatest number of human lives first.

64. General Principles of Firefighting
CONCEPT 3
Remove those in greatest danger first.
CONCEPT 4
When sufficient personnel are available to perform both functions, they must carry out a coordinated fire attack.
CONCEPT 5
When there is no threat to occupants, the lives of firefighters shouldn’t be unduly endangered.

65. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE
Objective :
The main objectives of Fire Drill and Emergency Evacuation procedure are as below :
• To provide an orderly emergency response plan for all occupants.
• To ensure all exit routes, emergency staircases are not obstructed and can be used in an orderly fashion during emergencies.

66. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE…
• To ensure fast, organised and smooth evacuation of buildings during emergencies.
• To train fire drill and emergency evacuation officers to conduct their duties successfully.
• To test the working conditions and effectiveness of all fire and emergency equipments for all buildings.

67. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE….
Planning :
Below are issues to be considered in planning and organising a fire drill and emergency evacuation:
Fire Protection

Type of warning signs.

Fire extinguisher, hose reel and fire fighting team.

Preparedness to call / contact the Security Department and Fire Brigade.

Selection of personnel from every building / floor to asssist in emergency evacuations.

68. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE…
Escape Route :

The sufficiency of existing evacuation routes for emergency evacuation and their clearance from any obstruction.

Measure the distance that occupants have to travel to get to the emergency assembly area during emergency
evacuation.

Ensure a safe and accessible emergency assembly area.

Emergency lights and availability of other emergency equipments.

69. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE…
Every personnel involved in the emergency response team need to be trained in assisting people during emergency evacuations.
• All activities conducted during fire drill and emergency evacuations are to be recorded and documented.

70. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE….
Preparation to Conduct Drill :
The items below are to be prepared prior to conduct a fire drill:
• Formation of emergency action committee for every
area. The appointments of officers shall include:

Emergency Evacuation officer and assistants

Floor leaders and assistants

71. FIRE DRILL & EMERGENCYEVACUATIONPROCEDURE…
Clarify the roles and responsibilities of every officer involved in the emergency action committee
• Prepare the floor plan and action plan.
• Determine the Assembly Area.
• Determine the evacuation route, exit doors, and emergency staircases are not obstructed.

72. FIRE DRILL & EMERGENCY EVACUATION PROCEDURE
Actions to be taken when conducting the Drill
• Sound the fire alarm (break the nearest “break-glass panel” to sound the fire alarm) and shout “FIRE, FIRE, FIRE..”
• If you encounter a small fire, try putting the fire out using the available fire fighting equipment closest to the scene. Try to control the situation.
• If you encouter a fire victim, rescue the victim without endangering yourself.
• Leave / evacuate the building and report at Assembly Area.

73. FIRE DRILL & EMERGENCY EVACUATION PROCEDURE
• Gather and Report to the officer in charge at the Evacuation Area. Ensure that your name is called during a headcount.
• When evacuating building, DO NOT:

Use the lift

Return to the office / room to take things

Overtake or push other evacuees
• If there are occupants who are sick, hurt or disabled, assist them to evacuate the building.
• Occupants may re-enter the building in an orderly fashion only AFTER the building is declared safe.

74. Fire Safety Inspection
Fire Safety Inspection should cover the following subjects :
i) Automatic fire suppression systems (eg: sprinkler systems).
ii) Fire hose reels.
iii) Fire hydrants.
iv) Automatic fire detection and alarm systems.
v) Fire doors.
vi) Fire extinguishers.
vii) Smoke exhaust systems.
viii) Exit signs.
ix) Emergency lighting.
x) Electrical Fire Control Measures.
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