Fire Extinguisher Testing & Inspection Services

Fire Extinguisher Servicing Guide For Consumers

Fire extinguishers that are installed in all commercial buildings, public buildings and certain multi-occupancy residential buildings need to be regularly inspected and tested by a competent person every six months.

The Australian Standard AS 1851 2012 Maintenance of Fire Protection Systems and Equipment specifies the fire extinguisher testing, maintenance and inspections that are required.

Examples of commercial buildings:

Offices, shopping centres, factories warehouses, restaurants, cafes, retail stores

Examples of public buildings:

Hospitals, schools, universities, libraries, theatres

Property owners, building managers, property managers, strata managers, tenants and the community in general should all be aware of some key points regarding the servicing of fire extinguishers to ensure they receive the appropriate level of service and are charged the correct amount for the services.

How To Use A Fire Extinguisher

The person looking to use a fire extinguisher should select the correct size and type of fire extinguisher most suitable for the relevant class of fire before undertaking the following:

1. Ensure that the area is accessible and safe; the fire must not be too hot or too large, and that there are no other immediate hazards to safety.
2. Contact the fire brigade.
3. Select the correct fire extinguisher relevant for the class of fire.
4. For using the fire extinguisher, the following acronym PASS - Pull, Aim, Squeeze, Sweep.
   1. Pull the pin of the fire extinguisher;
   2. Aim the extinguisher towards the base of the fire;
   3. Squeeze the handle;
   4. Sweep the extinguisher back and forth.

The fire may reignite even after it has been extinguished. Until the fire brigade arrives, secure another fire extinguisher if it’s safe enough and observe the scene of the fire.

Fire Extinguisher Tips

• The Australian Standard 2444 (AS 2444) Portable Fire Extinguishers and Fire Blankets Selection and Location will provide comprehensive information.
• Ensure everyone in the workplace or office knows the location of all extinguishers and how to use them.
• Extinguishers need to be pressure tested every five years by a registered organisation.
• Check that there are no blockages to the nozzle or outlet.
• If you have a dry chemical powder fire extinguisher (red with a white band or label). Turn the extinguisher upside down for a couple minutes every month to ensure that the powder is free flowing.
• Replace the extinguisher in case of rust or damage.
• If an extinguisher is discharged, even partially, it needs to be refilled by a registered organisation.

Types Of Fires - Which Fire Extinguisher To Use

Fires are classified as type A,B,C,D,E and F in our environment. Class A fires are burning solids like wood, paper etc. Class B fires are burning liquids like Petrol and Class E fires are Electrical fires. There are other fire types ("C" - Gas fires, "D" - metal fires, "F" - cooking fats). Extinguishers are marked with the classes of fire they can be used on. They also give an indication of how big a fire they can deal with, eg: 4A(E) says the extinguisher can deal with a small class "A" fire and is also suitable for electrical fires. The bigger the number the bigger the fire. You should know the ratings of all your extinguishers - in particular, you should know which ones have the "E" rating, since this is the most likely kind of fire in our building! For (hopefully) obvious reasons, water based extinguishers can not be used on electrical fires, or near powered equipment. Be sensible and cautious - even if you believe the burning computer is now unplugged - treat it as live.

Class A:

Solids such as paper, wood, plastic etc

Class B:

Flammable liquids such as petrol, oil etc

Class C:

Flammable gases such as propane, butane, methane etc

Class D:

Metals such as aluminium, magnesium, titanium etc

Class E:

Energized electrical equipment

Class F:

Cooking oils and fats etc

Fire safety is all about vigilance and preparation so our company provides different fire extinguishers to put out all 6 different classes of fires.  Here is a list of some of our offerings the fires they put our most effectively.

Water Fire Extinguishers

Puts out most class A fires by discharging to water to dampen the burning fuel

Carbon Dioxide Extinguishers

Puts out class B fires by displacing oxygen in the air preventing a fire from burning. This type is especially good for class E electronic fires.

Foam Extinguishers

Effective on class B fires due to the versatile properties of foams. It can dampen the fuel source or smother it making it a must around mechanics and refineries and other areas dealing with flammable liquids

Dry Chemical Powder Extinguishers

Versatile due to the unique powder agent this type can take care of most Class A, B, C and E fires.

Effective types of fire extinguishers for electrical fires

Electrical fires have the added hazard of the potential for electrocution while extinguishing it. For this reason, our company offers a line of extinguisher models made specifically to fight electrical fires. These are the Carbon Dioxide fire extinguishers (CO2 fire extinguishers).

Portable fire extinguishers

By definition, a portable fire extinguisher is an equipment utilised for extinguishing a fire. A portable fire extinguisher is only effective against the size and type of fire it is rated for.

In firefighting terms, portable fire extinguishers are used as "first attack" equipment. They are utilised only in the early stages of fire, up to the stage after which the fire grows beyond the chosen fire extinguisher’s capacity.

With Australia there are 5 main types of fire extinguishers available: carbon dioxide, dry chemical powder, wet chemical, foam and water. The extinguisher must be selected keeping in mind the class of fire it will be utilised against.

In 1723, the first patent of a fire extinguisher was launched by English scientist Ambrose Godfrey. The following 300 years experienced literally hundreds of variations and iterations over the basic design of the fire extinguisher.

If you analyse all the variations, you will be left with five common components present in every variant of the extinguisher manufactured in history. These are:

• a directional nozzle
• a valve
• an expellant (or propellant)
• an extinguishing agent
• a storage vessel

Modern fire extinguishers have continued to retain these common components. However, the advent of new technology has clearly resulted in improvements in the performance (rating and capacity) of extinguishers.

Fire Chemistry

Combustion (fire) is defined as a sequence of exothermic chemical reactions between an oxidant and a fuel accompanied by the by-products of combustion, namely electromagnetic radiation (light), smoke and heat.

There are four elements contributing to create the perfect environment for the initiation of fire and for its continuation. The four elements are namely:

• Chemical Reaction (Oxidation)
• Oxidant
• Heat
• Fuel

The effective removal of any one of these essential elements will result in the fire being extinguished.

In simple terms, a fire extinguisher works by influencing, eliminating or the ongoing effect of one or more of these four elements.

Classification Of Fires

The classification of fires is done in accordance with the fuel type and if there is a presence of live electrical equipment. The classification is very important, as it has direct influence over the selection and usage of the correct extinguisher for the fire situation. The fire extinguisher that is most relevant for extinguishing the fire.

The 6 classes of fire are:

• Class A - Ordinary Combustibles (such as plastics, wood, paper, etc.)
• Class B – Combustible and flammable liquids
• Class C - Flammable gases
• Class D - Combustible metals
• Class E - Electrically energised equipment
• Class F – Fats and cooking oils

Types Of Fire Extinguishers

As stated earlier, fire extinguishers are broadly categorised into 5 main types:

• Carbon dioxide
• Dry chemical powder
• Wet chemical
• Foam
• Water

For a given classification of fire, the selection of a fire extinguisher is shown by the colour code present in the body of the extinguishers.

Colouring and labels are the primary distinguishing factor for portable fire extinguishers.

The standard colour for portable fire extinguishers was changed in 1997. The extinguishers available in the market from this date were required to be polished stainless steel and painted red. Due to this change being relatively recent, extinguishers still use both Pre-1997 and Post 1997 colour schemes.

There is no universally acceptable type of fire extinguisher for all classes of fire. During selection of the most suitable variant of fire extinguisher, or combination of relevant fire extinguishers, each option must be carefully considered.

Water Fire Extinguishers (W)

A water-based extinguisher is also known as a stored pressure air-water fire extinguisher. This is because it’s a fire extinguisher that is stored under pressure (normally by air) and filled with water. These extinguishers are most applicable for Class A fires.

A water extinguisher cools the fire, interrupting the exothermic reaction. When the valve operated by a hand-held trigger is depressed, a water extinguisher starts operating. The water, contained and stored under pressure within the container is subsequently expelled.

Dry Chemical Powder (DCP)

The 2 main-types of dry chemical powder fire extinguisher are;

• BE Type - Effective on Class B, E & F fires.
• ABE Type - Effective on Class, A, B, C & E fires.

Dry chemical powder interrupts the oxidation process, making them very effective in controlling fires. The dry chemical powder, stored under pressure in the cylinder gets expelled when the hand-held trigger is depressed.

Note: There are special powders available for extinguishing fires where Class D combustible metals are involved.

Foam - Air/Foam (AF)

Air-foam fire extinguishers are either utilised against a class A or B fires, either as an aspirated (expanded & mixed with air via a branch pipe) or in a non-aspirated form. It subsequently creates a blanket of foam above the fuel, preventing the oxygen supply.

Wet Chemical (WC)

Wet chemical fire extinguishers are mainly installed in commercial kitchens for dealing with Class F fires (where the fuel is fats or cooking oils).

A wet chemical extinguisher smothers the burning oil by forming a blanket of soapy foam over it. This subsequently cools down the oil below its ignition point.

The chemical is expelled in the form of a fine mist that does not splash the grease onto other surfaces. Also, a Wet Chemical extinguisher can be safely used against “A” class fires.

Carbon Dioxide (CO2)

Carbon dioxide fire extinguishers are mostly useful against fire involving electrically energised equipment. Specifically where this electrically non conductive, inert gas, is most suited due to the minimal amount of clean up available from the agent. Areas that have expensive electrical equipment are a good example.

Carbon dioxide extinguishers are equipped with liquid CO2, that is subsequently expelled as a gas. Due to its heaviness when compared to air, carbon dioxide blankets a fire. It prevents oxygen from reaching the fire, depriving the burning fuel of oxygen. Carbon dioxide extinguishers are also effective against fires of Class “B” and “C”.

Unlike other chemicals used in fire extinguishers, CO2 doesn't adversely affect the environment by leaving a harmful residue. It also poses very little threat to electronic equipment employed in computer rooms, laboratories, and other sensitive areas with electrical equipment.

How Does A Fire Extinguisher Work?

Fire extinguishers expel an extinguishing agent when extinguishing a fire. The extinguishing agent is stored under pressure within a metal cylinder. When the hand-held trigger is depressed, the relevant valve opens releasing the agent.

Some fire extinguishers are equipped with a pressure gauge that offers a visual indication of its pressurised state. These gauges are colour coded, where green indicates whether the extinguisher is pressurised and ready for usage. It may also illustrate a numerical value indicating the same situation stated above.

Extinguisher Rating

The Australian Standard AS 1850 states that fire extinguishers must be marked with a rating and classification to comply with Australian Standards. The ratings of the extinguishers are calculated on the basis of their suitability and performance against a specific class of fire. A typical dry chemical extinguisher is marked 2A:40B: E, whereas a water extinguisher is marked 2A.
The number portrayed before the letter offers a measure of the relative performance within the relevant class as shown below:
• For Class A - Between 0 and 10
• For Class B - Between 2 and 80
• For Class F - Between 1 and 4

A higher number indicates that the extinguisher is more effective for that relevant class of fire. A fire extinguisher rated for several classes of fires are expressed in alphabetical order, i.e. 2A:40B: E.

There is a common misconception prevalent that 2 different fire extinguishers equipped with equal volume (Litres) or mass (Kg) must have the same rating. Every fire extinguisher is subjected to an array of standardised tests that ultimately determines their rating and suitability. These tests are conducted under the jurisdiction of the relevant local authority and in accordance with the building Code of Australia. It is mandatory to prominently display the final ratings on the sides of the relevant extinguisher.