Fire Extinguishers

All fire extinguishers are not created equally, there are a few different types and some are suited to better environments than others. For example, if you have a kitchen in your building and you have a fire involving oil or fats then you’re probably going to want to use a Wet Chemical Extinguisher but this type of extinguisher could be dangerous if used on an electrical fire.

There are 5 main fire extinguisher types in New Zealand – Water, Foam, Dry Powder, CO2, and Wet Chemical. You should have the right types of fire extinguishers for your house or business premises, or you may not meet current regulations.

The various types of fire extinguisher put out fires started with different types of fuel – these are called ‘classes’ of fire.  The fire risk from the different classes of fire in your home or your business premises will determine which fire extinguisher types you need.

You will also need to make sure that you have the right size and weight of fire extinguishers as well as the right kind.

Whilst there are 5 main types of fire extinguisher, there are different versions of Dry Powder extinguishers  The 6 types of fire extinguisher are:

– Water
– Foam
– Dry Powder – Standard
– Dry Powder – High performance
– Carbon Dioxide (‘CO2’)
– Wet Chemical

There is no one extinguisher type that works on all classes of fire.

Below is a summary of the classes of fire, and a quick reference chart showing which types of extinguisher should be used on each.  We then provide a detailed explanation of each type of fire extinguisher below.

Fire Extinguisher Guide

Fire Extinguisher Chart

Water and Foam

Water and Foam fire extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements.

Water extinguishers are for Class A fires only – they should not be used on Class B or C fires. The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.

Carbon Dioxide

Carbon Dioxide fire extinguishers extinguish a fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge.

Carbon dioxide can be used on Class B & C fires. They are usually ineffective on Class A fires.

Dry Chemical Powder

Dry Chemical Powder fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.

Today’s most widely used type of fire extinguisher is the multipurpose dry chemical that is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.

Ordinary dry chemical is for Class B & C fires only. It is important to use the correct extinguisher for the type of fuel! Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.

Wet Chemical

Wet Chemical is a new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements.

Wet Chemical extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.