Chapter 6

FIRE PREVENTION AND PROTECTION FOR THE HOUSE OWNER

Chapter Six: Fire Extinguishers

All areas of your home contain potential fire hazards. A well-placed fire extinguisher, if properly used, can prevent a small fire from getting bigger. They can also be used to reduce the intensity of a fire if it occurs in the only escape route. Fire extinguishers for the home are labelled according to the class and size of fire each is capable of putting out. There are rechargeable types and non-rechargeable types available. Whichever type you decide to purchase, it must be suitably approved. A clause in the National Fire Code states that a portable fire extinguisher shall not be sold or installed unless it conforms to one or more of four Canadian standards: ULC-S504, CAN4-S503, ULC-S512 and CAN4-S507. This clearly prohibits the sale of unapproved fire extinguishers. An additional method of extinguishing small fires is the reusable fire blanket, as described below.

This document does not include information on industrial extinguishers or large extinguishers that might be found in the common property areas of some apartment complexes.

Classification of Fires

There are three common types of fire that can occur in a residential home. Each type, or class, of fire must be fought with the proper type of extinguisher, so it is important to understand the classification of fires that can occur.

Class "A"

This is a fire of ordinary combustible materials (such as paper, wood, fabric, rubber, certain plastics, and other solids). As a memory-aid, think of "A" for Ashes, which typifies what is left after wood and paper have been burned.

Class "B"

This is a fire of flammable liquids (such as gasoline, cooking oils, greases, solvents, paints). Class B fires can be explosive. As a memory-aid, think of "B" for Boil, which is what liquids do when heated.

Class "C"

A Class C fire is one that involves live electrical circuitry (such as fires started by a short-circuit or faulty wiring in motors, switches, home appliances, etc). As a memory-aid, think of "C" for Current, which is a measure of electricity.

Class "D"

A fourth type of fire, which is uncommon in residential homes, is one that involves combustible metals (such as magnesium, sodium, potassium, etc.). It is included in this text for interest only and will not be considered further. A special extinguisher, not discussed in this document, will be required to put out a Class D fire.

Classifying and Labelling Extinguishers

Some extinguishers are designed to fight only one class of fire, while others are effective on two or all three common classes of fire. It is essential that you select the right size and type for each class of fire, because the wrong extinguisher used on a fire can do more harm than good. The class or classes of fire an extinguisher is intended for should be clearly shown on the cylinder of the extinguisher. A classification number is often included as a guide to the size of each type of fire an extinguisher can put out - the higher the number, the greater its capability. The classification letter and number are assigned by Underwriters' Laboratories of Canada (ULC), who test and approve the extinguisher, then allow the manufacturer to display the ULC symbol on the cylinder.

Class A rating

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To snuff a Class A fire you need to smother it and cool the burning material, otherwise the embers can rekindle as they gain oxygen and heat. That is why water is generally used to fight Class A fires. To earn a 1-A rating, an extinguisher is expected to put out a fire of 72 burning pieces of wood 4x4x50cm; 2-A can cope with a fire twice as big. Extinguishers suitable for Class A fires may be identified by a triangle containing the letter "A". If coloured, the triangle will be green. The extinguisher may have a pictorial marking label showing all three common classes of fires. If the extinguisher can be used on Class A fires, the picture will illustrate a burning trash can and logs on a green background. If it cannot be used on Class A fires, the same picture will be on a black background with a red diagonal line across it.

Class B rating

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A blanketing or smothering effect is essential in extinguishing this class of fire. Water will have no effect, and would tend to spread the fire by floating the burning liquids. To earn a 1-B rating, an extinguisher must discharge effectively for at least 8 seconds and snuff out 11L of flaming naptha in a 0.23 square-metre pan; 10-B can cope with a fire ten times as large. Extinguishers suitable for Class B fires may be identified by a square containing the letter "B". If coloured, the square will be red. The extinguisher may have a pictorial marking label showing all three common classes of fires. If the extinguisher can be used on Class B fires, the picture will illustrate a gas can and burning liquid on a red background. If it cannot be used on Class B fires, the same picture will be on a black background with a red diagonal line across it.

Class C rating

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In addition to its Class A and/or Class B rating, an extinguisher will have a Class C rating if it can be used on live electrical fires. A non-conductive agent is required to extinguish this class of fire. Water should not be used. When it is no longer electrically alive, a Class C fire becomes a Class A or Class B fire. There is no numerical value associated with a Class C extinguisher. Extinguishers suitable for Class C fires may be identified by a circle containing the letter "C". If coloured, the circle will be blue. The extinguisher may have a pictorial marking label showing all three common classes of fires. If the extinguisher can be used on Class C fires, the picture will illustrate a burning electrical plug on a blue background. If it cannot be used on Class C fires, the same picture will be on a black background with a red diagonal line across it.

Sizing of extinguishers

The Classification number will allow the user to determine the size of fire that a particular extinguisher is capable of snuffing out, while the weight will allow the user to determine how easy it is to handle the extinguisher. The extinguisher must be heavy enough to contain the right amount of chemicals to adequately extinguish a small fire, but be light enough to be operated by any member of the household who is old enough to handle a fire.

Extinguishers for residential use

Fire extinguishers available for residential use are usually capable of fighting more than one class of fire. They are labelled either ABC or BC. The appropriate markings are shown below.

Selecting a Fire Extinguisher for Residential Use

Selecting a fire extinguisher for use in a 1 or 2-family residential home is an important decision. Fortunately, it is possible to narrow the selecting to two or three different types. Selection is dependent on the following criteria:

Class of fire likely to be encountered.
Size of fire likely to be encountered.
Weight of extinguisher.
Ease of operation.
Certification.
Equipped with an easily read pressure guage.
Supplied with adequate mounting hardware.

Construction

Home fire extinguishers are composed of the cylinder holding a pressurized extinguishing agent, the head (which includes a valve, nozzle and pressure guage), a hand grip, and a mounting bracket (which is a requirement for extinguishers weighing over 1.4kg). The pressure guage lets you monitor the internal pressure inside the cylinder. When its needle is in the operating-pressure zone (usually green-coloured), the extinguisher is able to discharge properly.

Extinguishing agent

The cylinder may contain water (for Class A fires only), a liquified Halon gas (for Class B or C fires only), or a dry-chemical powder. The dry-chemical powders may be sodium or potassium bicarbonate (for Class B and C fires only), or ammonium phosphate (for Classes A, B amd C) - they have a range of about 3 metres, allowing you to stand a safe distance away, are non-toxic, and easy to vacuum after use. One disadvantage of dry-chemical powders is that they leave a residue that can damage electric motors, computers, television and stereo sets. A BCF or Halon 1211 gas extinguisher is a less damaging alternative for Class B and C fires - however, these are much more expensive and can be toxic in high concentration.

Rechargeable vs non-rechargeable extinguishers

Rechargeable extinguishers, although costing more, are generally better constructed and have a greater capacity for extinguishing fires than non-rechargeable types. Especially avoid types of non-rechargeable extinguishers that are not ULC approved, that come in a squeeze spray bottle, or that do not have a pressure indicator (some may have a plunger instead of a guage). Some non-rechargeable types are designed specifically for extinguishing BC-class fires in the kitchen and may be acceptable only for putting out small pan grease fires.

Selecting fire extinguishers for general use

For general use in the home, it is recommended that you consider purchasing only good-quality rechargeable types of fire extinguishers. The Consumers' Association of Canada suggests that a 2.3kg (5lb) multi-purpose (ABC-class) fire extinguisher be installed on each floor of the home. The extinguishers should be marked with the ULC logo and be easily operated by anyone in the household who is old enough to fight a fire. It must be equipped with an easy-to-read pressure guage and supplied with an adequate wall-mounting bracket. To successfully put out a fire, your extinguisher has to empty itself quite quickly and have good range. It must be able to be turned on and off several times during the course of fighting a fire and must not discharge its contents when dropped. Unfortunately, there are no regulations governing these latter requirements.

Selecting fire extinguishers for special areas

In addition to the general purpose ABC-class extinguisher recommended above, certain locations in your home may benefit from more specialized extinguishers. For example, in areas where you are concerned about fire in or near sensitive electronic equipment (computers, televisions, stereos, etc.) install a BC-class extinguisher which uses a BCF or Halon gas - this will not leave a damaging residue as would the dry chemical of an ABC-class extinguisher. In the garage, carport or automobile, where gasoline and grease fires are the major concern, install a dry chemical BC-class extinguisher.

Locating and Mounting Fire Extinguishers

For the ultimate protection, fire extinguishers should be placed in the kitchen, workshop, garage or carport, and in hallways leading to the bedrooms and living areas. In general, there should be an extinguisher within about 50 feet of any part of the house. Install at least one fire extinguisher on each floor of your house. The extinguisher should be firmly mounted no higher than five feet (1.5m) from the floor and in an accessible spot away from any specific fire hazards, such as the stove, gasoline containers, paints, solvents, etc. It should be placed near an exit, so that the user does not become trapped by the fire they are trying to extinguish. Follow the mounting instructions and heed the warning labels included with the fire extinguisher.

Maintenance

When purchasing a fire extinguisher, check the pressure-guage and ensure that the needle is pointing to the green area on the dial. As soon as possible, attach the date of purchase to the extinguisher. Often, a maintenance report card comes with the extinguisher - write the date of purchase on this card.

Since extinguishers use pressurized gas to discharge, it is essential to know at all times whether there is sufficient pressure in the canister. For this reason, inspect the extinguisher at least once a month and, in particular, check that it is fully charged and not damaged in any way. It is usually recommended that a rechargeable extinguisher be discharged and refilled with fresh chemical agent at least once every six years. Once a rechargeable extinguisher has been discharged (even partially) it should be refilled. Leave recharging to a professional. A non-rechargeable extinguisher should be replaced once it has been used. If dropped, an extinguisher should be serviced or replaced.

The Fire Blanket

In areas where small fires are more likely to occur (such as the kitchen and workshop, or around the barbeque or firework display), and where a fire extinguisher of the correct classification is not immediately within easy reach, it may be advantageous to keep a fire blanket handy. This is a non-flammable sheet of material, kept in a small package, that can be thrown over a small fire to smother the flames. It is reusable, non-conductive and can be used on any class of fire. It can be used to smother a clothing fire in the early stages, while protecting the hands from being burned. It should not be purchased as a substitute for a fire extinguisher, but it can be used where speed in smothering a fire is of the upmost importance.

Fire Extinguisher Operation

Learn to use the extinguisher

Study the manual that comes with the fire extinguisher before you install it. Its effectiveness in protecting your family and property depends on you knowing what it can and cannot do, how to use it, where to install it, and how to maintain it. Make sure the operating instructions are understood by everyone old enough to handle a fire. Don't wait for an emergency to learn how to use your extinguisher - it's worth the money (for recharging) to empty the cylinder once when you are cool and calm; but have it recharged immediately after using.

Deciding when to use a fire extinguisher

Most fires start small - except for explosions, fires can usually be brought under control if they are attacked correctly with the right type and size of extinguisher within the first two minutes. Before using an extinguisher to put out a fire ask yourself the following questions:

How big is the fire?
What is near the fire?
Am I in danger?
What is the type of fire?

If the fire is small, contained in one area (such as a waste basket), is not near any combustible material, and you are not in danger, you may consider fighting the fire yourself. Otherwise, evacuate the building and call the fire department immediately. If you have any doubts about fighting the fire yourself, then DON'T.

Fighting a small fire

There are a number of steps you should take when fighting a small fire by yourself. These are summarized in the flow chart below:

If you are not alone, yell to other members of the household to leave the premises and call the fire department from a neighbour's phone - just in case you are unable to control the fire.

If electricity is involved, whether it be the direct cause of the fire or just located near to the fire source, turn off the power and/or unplug the item(s) from the wall socket. Once this is done the fire can be treated as a Class A or Class B fire. However, if you are not able to disconnect the power, you must use a Class C extinguisher.

Both Class A and Class B fires can be extinguished by smothering (ie. cutting off the supply of oxygen to the fire). This can be accomplished by using the appropriate extinguisher if the correct type is within easy reach. Alternative methods of smothering the fire include using a fire blanket, a metal pot lid or baking powder. After smothering a Class A fire, dowse the embers with water to ensure that they have cooled sufficiently to prevent rekindling.

A small Class A fire, as long as it does not involve electricity, can be smothered and cooled at the same time by using water from a pitcher or a hose. This can be done if a Class A extinguisher is not immediately available.

If the fire does not extinguish quickly, or it starts spreading, don't continue fighting it yourself. Leave the building and call the fire department from a neighbour's phone (if this has not already been done).

Using a fire extinguisher

If you have decided that it is safe to use a fire extinguisher and you are not sure how to operate it, check the label on the extinguisher for instructions. As a general memory aid, recall the word "PASS" which stands for:

Pull (the pin)
Aim (the nozzle at the base of the fire)
Squeeze (the trigger)
Sweep (from side to side)

In general, hold the extinguisher upright, keep at least 1.8m (6 feet) from the fire and near an exit, then aim the nozzle at the base of the fire (not at the flames or smoke). Liquid fires call for a sweeping spray, but intermittent blasts are recommended for other types of fire. Play it safe! Keep away from the fire's fuel source and avoid breathing vapours, fumes and heated smoke as much as possible. Even when the fire is out, smouldering furniture should be soaked thoroughly. To be extra safe, put affected cushions and mattresses outdoors for several hours after they have been soaked.

After the fire

If you manage to extinguish the fire yourself and have made quite sure that it will not flare up again, remove the burned items from the house and clean up the mess. If you used an extinguisher (no matter how little) have it recharged as soon as possible and replace it in its mounting bracket.

Summary

The types of fire extinguishers for use in the home are summarized in the flow chart below. Appendix C will aid you in planning the placement of extinguishers. You may also wish to consider the purchase of one or more fire blankets for potentially hazardous areas and events.

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