Fire-Causes & Theory 02

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Fire Safety:

Fire Safety 1

Session 1::

Session 1: Possible causes of fire 2

Session Objectives:

Session Objectives By the end of this session, learners will be able to: State the components necessary for a fire to start and continue. Explain the causes of fire. State the safety precautions to avoid fire hazards. 3

Fire and Fire Safety:

Fire and Fire Safety Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included in this definition. 4

Fire Safety:

Fire Safety Refers to the precautions taken to prevent or reduce the likelihood of a fire. These include: Measures incorporated when planning construction: Means of alerting people inside a building of the possibility or occurrence of fire. Means of escape in case of fire. Reducing damage caused by fire. Training personnel: Instructing occupants of buildings. Conducting safety drills. 5

Fire hazards :

Fire hazards These are any threats to fire safety. They may include situations that: Increase the likelihood of a fire. Impede escape in the event of a fire. 6

Elements of Fire:

Elements of Fire Three elements are essential for fire to start and continue: Fuel : Any combustible substance in solid, liquid or gaseous form. Oxygen : Usually supplied from the air which contains approximately 20% oxygen. Heat : The amount required varies with different materials. 7

Theory of Combustion and Extinguishment :

Theory of Combustion and Extinguishment The basic requirements of fire are Fuel ,Oxygen ,Heat l Oxygen is required to support combustion: Usually drawn from the atmosphere. Some materials like explosives contain sufficient oxygen. Heat: Most solids and liquids require heat above their normal temperature to emit flammable vapour. Some liquids like petrol or methylated spirit are flammable at normal temperature. 8

Types of Extinguishment :

Types of Extinguishment Fire can be extinguished by limiting one or more of the three essential elements in the triangle of combustion. The methods are: Starvation. Smothering. Cooling. 9


Contd. Starvation Remove combustible material from the reach of flames. Remove the fire from access to combustible material. Subdivide or separate the burning material. Smothering Combustion will cease if the oxygen content of the air immediately surrounding the burning material is reduced to at least 15%. To achieve this, apply: Viscous coating such as foam on the burning material. Cloud of finely divided particles of dry powder from a pressuriser . Inert gas, steam or vaporising liquid from a fire extinguisher. 10


Contd. Cooling Water is the most commonly used media. It is available in large quantities and at low cost. Note: The categorisation of fire may vary slightly from country to country. 11

Possible Causes of Fire:

Possible Causes of Fire Fire is caused by one or a combination of the following factors: Human error. Poor maintenance. Mechanical faults. Accidents. Electrical faults. Lightening. Smoking. Arson. 12


Contd. Human error This is unintentional but results in a dangerous situation. It could happen when people: Fail to do something when action is required. Do what they think is right but has the wrong outcome.   Poor maintenance Failure to check that infrastructure and equipment are in good shape, not worn out or prone to cause fire. 13


Contd. Mechanical faults These include: Load imbalance. Shaft misalignment in induction motors. 14


Contd. Accidents An accident is a specific, unexpected, unusual and unintended external action with no apparent and deliberate cause but with marked effects. It implies a negative outcome that may have been avoided or prevented had the circumstances leading up to the accident been recognised and acted upon, prior to its occurrence. 15


Contd. Electrical faults These occur when: An electrical current flows through a circuit during a fault condition. - One or more electrical conductors come in contact with the ground and/or each other. Lightening It occurs when positive and negative charges build up too much energy and explode in a flash of light. Tall objects or trees in the way of this movement of energy and light between the atmosphere and the ground are struck by the lightening. 16


Contd. Smoking Simmering cigarette butts can ignite easily flammable material like paper. Particularly dangerous if it falls on wiring, oil or other fuel, chemicals or even a carpet. Arson Deliberately setting fire to material or property. It is a criminal act which is severely punishable by law. 17

Session Summery:

Session Summery The key points discussed are:- The components necessary for a fire to start and continue. Causes of fire. Safety precautions to avoid fire hazards.     18

PowerPoint Presentation:

Thanks For Patience Listening 19

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