Types of Fire Extinguishers and Their Uses (As Per International Standards)
Introduction
Fire extinguishers are critical safety devices designed to combat different classes of fires. Their effectiveness depends on using the correct type for the specific fire hazard. International standards such as NFPA 10 (USA), EN 3 (Europe), and ISO 7165 classify extinguishers based on their extinguishing agents and suitability for fire classes (A, B, C, D, K/F).
Below is a detailed guide on the five main types of fire extinguishers, their uses, and examples of fires they can suppress.
1. Water Fire Extinguishers (Class A Fires)
Standard Compliance: NFPA 10, EN 3
Color Code: Red (with additional label for water type)
Extinguishing Agent: Pressurized water (sometimes with additives for better penetration).
Uses:
- Effective on ordinary combustibles (wood, paper, textiles).
- Not suitable for electrical, flammable liquid, or metal fires.
Examples of Fires It Can Extinguish:
- Burning wooden furniture
- Paper or cardboard fires
- Cloth or fabric fires
- Rubbish bin fires
- Forest/brush fires (in outdoor settings)
Warning: Never use on electrical or grease fires (risk of electrocution or splashing).
2. Foam (AFFF) Fire Extinguishers (Class A & B Fires)
Standard Compliance: NFPA 11, EN 3
Color Code: Red (cream-colored label for foam)
Extinguishing Agent: Aqueous Film-Forming Foam (AFFF).
Uses:
- Smothers flammable liquid fires (gasoline, oil).
- Can also work on solid combustibles (Class A).
Examples of Fires It Can Extinguish:
- Petrol or diesel spills
- Burning alcohol (ethanol, methanol)
- Paint or solvent fires
- Burning plastics (if not electrical)
- Industrial chemical fires (non-reactive)
Limitation: Not suitable for electrical or metal fires.
3. CO₂ (Carbon Dioxide) Fire Extinguishers (Class B & C Fires)
Standard Compliance: NFPA 12, EN 3
Color Code: Red (black label for CO₂)
Extinguishing Agent: Pressurized carbon dioxide gas.
Uses:
- Ideal for electrical fires (non-conductive).
- Effective on flammable liquids (no residue).
Examples of Fires It Can Extinguish:
- Electrical panel fires
- Server room fires
- Burning gasoline in labs
- Flammable solvent fires
- Industrial machinery fires
Warning: Not for Class A (ineffective on solids) or Class D (metal fires).
4. Dry Chemical (ABC Powder) Fire Extinguishers (Class A, B, C Fires)
Standard Compliance: NFPA 10, EN 3
Color Code: Red (blue label for powder)
Extinguishing Agent: Monoammonium phosphate or sodium bicarbonate.
Uses:
- Most versatile (works on solids, liquids, and electrical fires).
- Leaves residue (not ideal for sensitive electronics).
Examples of Fires It Can Extinguish:
- Office fires (paper, wiring)
- Vehicle engine fires
- Industrial chemical fires
- Electrical equipment fires
- Household fires (mixed fuel types)
Limitation: Not for Class D (metal) or Class K (grease) fires.
5. Wet Chemical Fire Extinguishers (Class K/F Fires – Kitchen Fires)
Standard Compliance: NFPA 17A, EN 3
Color Code: Red (yellow label for wet chemical)
Extinguishing Agent: Potassium acetate or citrate-based solution.
Uses:
- Specifically for cooking oil & fat fires.
- Cools flames and creates a foam barrier.
Examples of Fires It Can Extinguish:
- Deep fryer fires
- Grease fires on stoves
- Commercial kitchen flare-ups
- Animal fat fires
- Industrial food processing fires
Note: Only for Class K (NFPA) or Class F (EN) fires—not for other fire types.
Specialized Extinguishers (Class D – Metal Fires)
Standard Compliance: NFPA 484, EN 3
Color Code: Red (yellow label with “Class D” marking)
Extinguishing Agent: Sodium chloride or graphite-based powder.
Uses:
- Only for combustible metals (magnesium, lithium, sodium).
Examples of Fires It Can Extinguish:
- Magnesium alloy fires
- Lithium battery fires (in certain cases)
- Titanium machining fires
- Sodium/potassium lab fires
- Aluminum powder explosions
Critical Note: Never use water or standard extinguishers on metal fires.
Conclusion
Choosing the right fire extinguisher is crucial for safety. The NFPA, EN, and ISO standards ensure uniformity in classification and usage. Key takeaways:
- Water & Foam – Best for solids/liquids (A & B).
- CO₂ – Ideal for electrical/flammable liquid fires (B & C).
- Dry Chemical (ABC) – Most versatile (A, B, C).
- Wet Chemical – Only for kitchen fires (K/F).
- Class D Powder – Exclusively for metal fires.
Always check local regulations (OSHA, BSI, or DGUV) for compliance.
Emergency Preparedness: Fire Safety, Evacuation Drills, First Aid
Methods of Fire Extinguishment (As Per NFPA and International Standards)
Classification of Fire – Understanding Different Types of Fire (Based on International Standards)
FAQs
1. What are the different types of fire extinguishers, and how are they classified?
Fire extinguishers are classified based on the type of fire they can combat. The international standard (ISO 7165, NFPA 10, and EN 3) categorizes them into the following classes:
- Class A: Fires involving ordinary combustibles (wood, paper, cloth).
- Class B: Fires involving flammable liquids (gasoline, oil, grease).
- Class C: Fires involving electrical equipment.
- Class D: Fires involving combustible metals (magnesium, sodium).
- Class K: Fires involving cooking oils and fats (commercial kitchens).
Fire extinguishers are labeled with letters and symbols to indicate their suitability.
2. What is a Water Fire Extinguisher, and when should it be used?
Type: Class A
Use: Effective on ordinary combustibles like wood, paper, and textiles.
How it works: Cools the fire by absorbing heat.
Limitations:
- Should never be used on electrical (Class C), flammable liquid (Class B), or metal (Class D) fires.
- Can freeze in cold climates unless antifreeze is added.
3. What is a Foam (AFFF) Fire Extinguisher, and where is it used?
Type: Class A & B
Use: Effective on flammable liquids (gasoline, oil) and solid combustibles.
How it works: Forms a foam layer that smothers the fire and prevents re-ignition.
Limitations:
- Not suitable for electrical or metal fires.
- May cause contamination in sensitive environments.
4. What is a Dry Chemical (ABC) Fire Extinguisher, and why is it versatile?
Type: Class A, B, C (some are BC only)
Use: Multipurpose extinguisher for wood, liquids, and electrical fires.
How it works: Releases a fine powder (monoammonium phosphate or sodium bicarbonate) to interrupt chemical reactions.
Limitations:
- Leaves residue that can damage electronics.
- Not suitable for metal (Class D) or kitchen (Class K) fires.
5. What is a CO₂ Fire Extinguisher, and where is it best used?
Type: Class B & C
Use: Ideal for electrical fires (servers, wiring) and flammable liquids.
How it works: Displaces oxygen and cools the fire.
Limitations:
- Not effective on Class A fires (does not cool sufficiently).
- Risk of asphyxiation in confined spaces.
