This document discusses fire and explosions, including: 1. The fire triangle requires three elements - fuel, oxygen, and an ignition source. Different types of combustion exist depending on the combustion rate. 2. Factors that influence fire include minimum ignition temperature, auto-ignition temperature, flammable ranges, gas densities, and catalysts. 3. Fires are classified A-F based on their fuel. Proper extinguishing agents must be selected depending on the fire type to safely put it out.

1. MODULE 8- FIRE AND
EXPLOSIONS
SAFE COMPANY

2. CHARACTERISTICS OF FIRE
 Fire can cause large losses (human & materials)
 Chemical reaction requiring three components: fuel, oxygen and an
ignition source (fire triangle).If any one of these three components is
missing, a fire cannot start! The ratio has to be right.
 Ignition can be caused by convention, conduction and radiation.
 Several types of combustion process depending on the combustion
rate: Slow combustion (no flames and temperatures very low),
normal combustion (controlled combustion process), explosion (very
quickly), detonation (very quickly and propagates very quickly).

3. INFLUENCING FACTORS
 Minimum ignition temperature: flash point.
 The temperature at which the substance catches fire spontaneously:
auto-ignition temperature.
 The range between the upper and lower explosion limit is called the
flammable range, indicating the range for which the ratio of gas to
air is dangerous.
 The alarm phase is reached as soon as the concentration of a gas
or vapor exceeds 10 percent of the lower explosion limit.

4. INFLUENCING FACTORS II
 The density of a gas is an important factor in determining whether
the risk of explosion exists and to eliminate that danger.
 Catalysts: substance which makes another substance flammable.
 Oxidizing substances: When heated, these substances give off
additional oxygen, which causes the fire to intensify.

5. CLASSIFICATION OF FIRES
 A (fuelled by solids, no metal. Extinguished with water or foam),
 B (fuelled by a liquid or a solid that melts because of the heat.
Extinguished with powder, CO2 or foam but NEVER with water!),
 C (fuelled by a gas, extinguished with powder)
 D (fuelled by combustible metals, extinguished with special powders
or dry sand).
 E (caused by electrical installations, put out with CO2).
 F (cooking fires, caused by oils/ fats.

6. EXTINGUISHING AGENTS
Several types of extinguishing agents can be used to put out a fire
depending on the nature and the size of the blaze:
A wrong extinguishing method may have catastrophic consequences!
• Water: most frequently. It is very efficient to extinguish fires involving
solids. Disadvantages: conducts electricity and few chemicals that
react violently, freeze.
• Sand: isolates the fire from the oxygen it requires. Disadvantage:
lumps and hardens easily.

7. EXTINGUISHING AGENTS II
• Powder: suited to nearly every type of fire. Not all powders have the
same characteristics, label. Disadvantage: damage, mess, reduce
visibility in small spaces.
• Foam: dry fires, Disadvantage: conducts electricity and is
susceptible to freezing. damaging to the environment.
• CO2 ideal for electrical fires. Disadvantage: suffocating effect.

8. FIRE EXTINGUISHERS
 Fire Extinguishers: portable, red in color, can be filled with different
extinguishing agents. label indicates the type of agent the
extinguisher contains.
 Fire Blanket: non-flammable fabric, smothers the fire by cutting off
its oxygen supply.
 Fire Hydrant: valve installed above or below ground, connected to
the water mains.
 Fire Hose Reel : drum supporting a rolled-up fire hose that´s
connected to the water mains. Only suited for extinguishing solid
fuel fires. Only used for trained personnel.

9. FACING THE FIRE
Steps to follow in case of fire:
• Act quickly. Do not panic. Start by saving yourself.
• Alert the emergency services or the person in charge or push the
alarm button.
• Fire marshals: personnel assisting co-workers in case of fire. Easy
recognizable. Trained. Ensuring evacuation (specially disabled)
• Follow the directions of the fire brigade and those in charge of the
evacuation.
• NEVER use the elevator, take the stairs instead. Use the handrails.

10. FACING THE FIRE II
Take in mind in case of fire:
• Only try to extinguish after reporting it, clearing exit and if you know
how and what extinguisher has to be used.
• Fire Extinguishers: PASS CODE (pull the pin, aim at the base of
flames, squeeze the trigger and sweep from side to side)
• In case of fumes: stoop and crawl. Check the doors before opening.
If hot, try another door.
• If clothes get fired: get clear, drop to the ground and roll.

11. PREVENTING FIRES
Important aspects to prevent fires:
• Fire risk assesment: identifying hazard, assestment, controlling the
hazards, training personnel, visible fire procedures.
• Extinguishers must be clearly identified and regularly tested
• No liquids (drinks) near electrical equipment.
• Empty waste periodically.
• Checking the label and safety data sheets of chemicals substances
present at work: important information to avoid fires.

12. FIRST AID
How to help in case someone is burned:
• Water first, everything else can wait!
• Cool the burned body part under cold running water for at least 15
minutes.
• Clothing that is stuck to the burn should be left in place until the
emergency services arrive.