• WATER Type Extinguishers

Water extinguishers are only acceptable for class A fires. Never use a water extinguisher on a grease fire, an electrical fire, or a class D fire because the flames will spread and make the fire worse! Water extinguishers are loaded with water and pressured with oxygen. Using a water extinguisher incorrectly can be quite dangerous.

• Dry CHEMICAL Extinguishers

Dry Chemical Extinguisher are available in different types and considered suitable for extinguishing fires with a combination of class A, B and C. This type of extinguisher contains foam or powder and pressurized with nitrogen.

o BC - During the application BC type of extinguisher produces a somewhat mild corrosive type of residue that must be cleaned as soon as possible to avoid any damage to the material.
o ABC - This is a special type of multipurpose dry chemical extinguisher and is loaded with mono ammonium phosphate, a yellow powder that leaves a sticky residue that may be damaging to electrical appliances such as a computer.

Dry chemical type of fire extinguishers has an advantage over CO2 type of fire extinguishers as they leave a non-flammable coating on the extinguished material, reducing the probability of re-ignition.

• CARBON DIOXIDE (CO2) Extinguishers

They are loaded with carbon dioxide, a non-flammable gas, under high pressure. They don't work very well on class A fires because they may not be able to displace enough oxygen to completely extinguish the fire, leading it to the probability of re-ignition. They are used for Class B and C fires.

• METAL/S Fire Extinguishers

They are used for flammable metal fires (class D fires) and work simply by smothering the fire. The most widely used common extinguishing agent in this class of fire is sodium chloride, but other options are also available. Types of class D extinguishing units are

1. For metal fires including magnesium, sodium, potassium, sodium/potassium alloys, uranium, and powdered aluminum, sodium chloride (NaCl) works effectively. Heat from the fire causes the agent to cake and produce a crust that excludes air and dissipates heat.
2. For flames involving lithium and lithium alloys, powdered copper metal (Cu metal) is preferred.
3. Now-a-days Graphite-based powders are also designed for use on lithium fires. This chemical can also be used to extinguish fires that involves high-melting metals like zirconium and titanium.
4. Specially-designed sodium bicarbonate-based dry agents can suppress fires involved with most metal alkyls, pyrophoric liquids ( such as triethylaluminum) which have a tendency ignite when comes in contact with air, but cannot be relied on a standard BC extinguisher for this purpose.
5. Sodium carbonate-based dry powders can be used with most Class D fires involving sodium, potassium or sodium/potassium alloys. When stress corrosion of stainless steel must be kept to a bare minimum, this agent is recommended.