Understanding Fire: Origins, Risks, and Safety Measures
The Origin of Fire
Four Factors for Fire Ignition
Fire occurs when four factors coincide in space and time:
- Fuel: Any substance capable of undergoing combustion. This includes:
- Solid fuels (e.g., wood, coal)
- Liquid fuels (e.g., gasoline, diesel)
- Gaseous fuels (some support combustion, others suppress it)
- Thermal (e.g., furnaces)
- Electrical (e.g., switches)
- Mechanical (e.g., sparks from tools)
- Chemical (e.g., exothermic reactions)
Key Combustible Material Properties
- Flash Point: The minimum temperature at which flammable gas ignites without a flame.
- Ignition Temperature: The minimum temperature at which a substance ignites.
- Flammability Limits: The concentration range of a fuel-oxidizer mixture that can support combustion.
- Calorific Value: The energy released during combustion per unit mass of fuel.
Heat Transmission
Heat spreads through:
- Conduction: Direct contact through a conductive medium.
- Convection: Movement of heat through gases (air).
- Radiation: Heat transfer through space in straight lines, without contact.
Combustion Types
Combustion is an oxidation reaction between fuel and oxidizer, initiated by activation energy and releasing heat.
- Smoldering: Slow combustion with minimal light and heat.
- Rapid Combustion (Fire): Intense light and heat, with flames spreading at less than 1 m/sec.
Results of Combustion
- Smoke: Visible particles from incomplete combustion.
- Flame: Glowing gas, a destructive factor of combustion.
- Heat: A major contributor to fire damage.
- Gases: Products of combustion, some toxic (e.g., carbon monoxide).
Fire Suppression Methods
- Dilution (Desalimentación): Removing or reducing the fuel supply.
- Choking (Inerting): Eliminating oxygen or preventing fuel vapors from contacting oxygen.
- Cooling: Reducing the fuel temperature.
- Inhibition: Disrupting the chain reaction by preventing heat transfer.
Classes of Fire
- Class A: Fires involving solid combustibles that leave embers (e.g., wood, paper).
- Class B: Fires involving flammable liquids (e.g., gasoline, oil).
- Class C: Electrical fires.
- Class D: Fires involving combustible metals (e.g., magnesium, aluminum).
Causes of Fire
- Natural Causes: Lightning, magnifying glass effect.
- Human Causes: Recklessness, negligence, improper fire handling.
- Electrical: Overloads, short circuits.
- Heating: Fireplaces, stoves.
- Flammable Liquids and Gases: Improper storage or handling.
Risks of Fire
- Smoke Inhalation
- Toxic Gases
- Burns from Heat
- Panic and Injury During Evacuation
Fire Safety Measures
Fire Protection Measures
- Saving Lives
- Minimizing Economic Losses
- Ensuring Business Continuity
Preventive Measures
Limiting the possibility of fire occurrence.
Active Protection Measures
Facilities for fire extinguishment, including:
- Detection systems
- Warning and signaling systems
- Extinguishing systems (e.g., fire extinguishers, hydrants, sprinklers)
Types of Extinguishing Systems
- Fire Extinguishers: Portable devices for initial fire fighting.
- Hydrants: Permanently installed, higher capacity than extinguishers.
- Fire Hydrants Equipped (BIES): Independent water intake, hose, and lance.
- Sprinklers: Network of pipes with sprinkler heads activated by heat.
- Dry Columns: Empty pipes connected to a water source for firefighting equipment.
Passive Protection Measures
Building design and construction features that facilitate evacuation and contain fire spread.
Objectives of Fire Compartmentalization
- Enhance evacuation safety
- Protect hazardous areas
- Prevent rapid smoke spread
- Reduce material damage by confining the fire
Self-Protection Handbook
A guide for emergency evacuation, typically required for certain building types. It includes:
- Document 1: Risk Assessment
- Document 2: Means of Protection
- Document 3: Emergency Plan
- Document 4: Implementation