Fire Extinguisher Types: A Detailed Guide

Fire extinguishers are essential safety devices that help control or extinguish small fires in emergency situations.

There are various types of fire extinguishers, each designed to combat different classes of fire. In this article, we’ll dive into the different types of fire extinguishers, their uses, and the specific classes of fire they target.

Table of Contents

Fire Classification
Fire Extinguisher Commissioning
Conclusion

Fire Classification

Before exploring fire extinguishers, it’s important to understand fire classification. Fires are classified based on the type of material that fuels them:

Class	Fire Type	Examples
Class A	Fires involving ordinary combustible materials	Wood, paper, cloth, rubber, plastics
Class B	Fires involving flammable liquids	Petrol, oil, grease, paint, solvents
Class C	Fires involving flammable gases	Propane, butane, methane, natural gas
Class D	Fires involving combustible metals	Magnesium, titanium, potassium, sodium
Class F	Fires involving cooking oils and fats	Vegetable oils, animal fats (mostly found in commercial kitchens)

1. Water Fire Extinguishers

Suitable for: Class A fires (Combustible materials)
Appearance: Usually solid red with no colored band.

Water extinguishers are the most common and work by cooling the burning material below its ignition point. They are effective against fires involving paper, wood, textiles, and other organic materials. However, they are not suitable for electrical fires, flammable liquid fires (Class B), or cooking oil fires (Class F).

Fire Extinguisher Type	Usage Class	Pros	Cons
Water Extinguisher	Class A	Simple and widely available	Unsafe for electrical, liquid, and gas fires

2. CO₂ Fire Extinguishers

Suitable for: Class B (Flammable liquids) and Class C fires (Flammable gases)
Appearance: Black label.

CO₂ extinguishers work by displacing oxygen, effectively smothering the fire. They do not leave any residue, making them suitable for use in areas with sensitive electronic equipment, such as offices and server rooms. However, they are ineffective on Class A fires and cannot cool materials, which means the fire could reignite if the source is not completely controlled.

Fire Extinguisher Type	Usage Class	Pros	Cons
CO₂ Extinguisher	Class B and C	No residue, safe for electrical equipment	Ineffective for Class A fires, limited cooling

3. Foam Fire Extinguishers

Suitable for: Class A and Class B fires (Flammable liquids)
Appearance: Cream-colored label.

Foam extinguishers create a blanket of foam over the fire, cutting off the oxygen supply and cooling the burning material. They are versatile and work on both solid materials and liquid fires but are unsuitable for electrical fires and Class F fires.

Fire Extinguisher Type	Usage Class	Pros	Cons
Foam Extinguisher	Class A and B	Versatile, good for solid and liquid fires	Ineffective for electrical and gas fires

4. Wet Chemical Fire Extinguishers

Suitable for: Class F fires (Cooking oils and fats) and Class A fires.
Appearance: Yellow label.

Wet chemical extinguishers are designed for kitchen fires involving cooking oils (Class F). They work by creating a cooling blanket of foam that prevents re-ignition. The wet chemical also reacts with the fat, creating a soapy layer that helps smother the flames. This type of extinguisher can also be used on Class A fires.

Fire Extinguisher Type	Usage Class	Pros	Cons
Wet Chemical Extinguisher	Class F and A	Ideal for kitchen fires	Not effective for flammable liquids or gases

5. Dry Powder Fire Extinguishers

Suitable for: Class A, B, C, and electrical fires.
Appearance: Blue label.

Dry powder extinguishers are multipurpose, designed to handle a wide range of fire types, including flammable liquids, gases, and electrical fires. They work by forming a barrier between the fire and the oxygen supply. However, dry powder extinguishers leave a messy residue and are not recommended for use in enclosed spaces due to the risk of inhalation.

Fire Extinguisher Type	Usage Class	Pros	Cons
Dry Powder Extinguisher	Class A, B, C, Electrical	Versatile, effective on multiple fire types	Messy, unsuitable for indoor use

6. Dry Chemical Fire Extinguishers

Suitable for: Class A, B, C, and electrical fires.
Appearance: Red cylinder with a white band.

Dry chemical extinguishers are highly effective and multipurpose. They work by interrupting the chemical reaction of the fire triangle (fuel, heat, and oxygen). Dry chemical extinguishers can extinguish Class A (solid materials), Class B (flammable liquids), and Class C (flammable gases) fires. They are commonly used in many settings due to their versatility but leave a residue that can damage sensitive electronics.

Fire Extinguisher Type	Usage Class	Pros	Cons
Dry Chemical Extinguisher	Class A, B, C, Electrical	Effective on a wide range of fires	Residue can be damaging to electronics

7. Class D Extinguishers

Suitable for: Class D fires (Combustible metals).
Appearance: Yellow label.

Class D extinguishers are designed to fight fires involving combustible metals such as magnesium, titanium, and sodium. They work by smothering the fire with a dry powder that doesn’t react with the burning metal. These extinguishers are specialized and not commonly found in everyday environments.

Fire Extinguisher Type	Usage Class	Pros	Cons
Class D Extinguisher	Class D	Designed for metal fires	Limited use, not versatile

8. Clean Agent Fire Extinguishers

Suitable for: Class A, B, C, and electrical fires.
Appearance: Green label.

Clean agent extinguishers use gases such as halon or halocarbon to suppress fire by interrupting its chemical reaction. They leave no residue, making them ideal for areas with sensitive electronics, such as data centers. However, they are less common and can be expensive.

Fire Extinguisher Type	Usage Class	Pros	Cons
Clean Agent Extinguisher	Class A, B, C, Electrical	No residue, safe for electronics	Expensive, limited availability

Fire Extinguisher Commissioning

Fire extinguishers must be properly commissioned, meaning they are installed, tested, and maintained by a competent person. This ensures that they will function correctly in the event of an emergency. Key aspects of commissioning include:

Correct Placement: Extinguishers should be placed in easily accessible locations based on the types of fire risks present.
Regular Inspection: Fire extinguishers must be inspected regularly to ensure they are fully operational, with gauges indicating correct pressure.
Annual Servicing: Extinguishers should undergo servicing at least once a year by a certified technician.
Tagging: All fire extinguishers must have tags indicating their last inspection date and servicing records.

Aspect	Details
Correct Placement	Place based on fire risks
Regular Inspection	Ensure gauges and nozzles are working
Annual Servicing	Certified technician required
Tagging	Must have inspection and service tags

Conclusion

Understanding the different types of fire extinguishers and their appropriate uses is crucial for ensuring fire safety in any environment. The table below summarizes the main points:

Extinguisher Type	Fire Class	Key Features
Water	Class A	Cools burning material
Foam	Class A, B	Cuts off oxygen supply, cools material
CO₂	Class B, C	Smothers fire by displacing oxygen, no residue
Dry Powder	Class A, B, C, Electrical	Versatile but leaves messy residue
Wet Chemical	Class F, A	Ideal for kitchen fires, creates foam barrier
Dry Chemical	Class A, B, C, Electrical	Multipurpose but leaves damaging residue
Class D	Class D	Specialized for metal fires
Clean Agent	Class A, B, C, Electrical	No residue, ideal for electronics

Proper fire extinguisher selection and maintenance are vital for any fire safety plan. Each type is designed to tackle specific fire hazards, and knowing which one to use can make all the difference in an emergency.

Fire Extinguisher Types: A Detailed Guide