Fire Extinguisher Safety in Canada: Classes & the Law

Fires are one of the few workplace hazards that can destroy a business and take lives in the same afternoon. In the jurisdictions reporting to Canada's National Fire Information Database, a single decade (2005–2014) saw 439,256 fire incidents, 1,733 fire-related deaths and 12,503 injuries — and structure fires burn in workplaces of every kind: industrial, mercantile, business, institutional and assembly properties, not just homes. 2 Most start small.

Whether a small fire stays small often comes down to two things: whether the right extinguisher is within reach, and whether someone nearby knows how — and when — to use it. This guide to fire extinguisher safety covers the fire classes, extinguisher types, the PASS technique, what federal and provincial law actually requires, and the training employers must provide and workers need.

What is the fire triangle — and the fire tetrahedron?

Fire needs three things to begin: fuel, oxygen, and enough heat to bring the fuel to its ignition temperature. Those three make up the classic fire triangle. 1

Modern fire science adds a fourth element, the chemical chain reaction that keeps combustion going once it has started, and that fourth element extends the triangle into the fire tetrahedron. All four have to be present at the same time for a fire to burn, and removing any one of them means the fire cannot sustain itself. 1

• Fuel — any combustible material, including paper, wood, cloth, rubber, plastics, and flammable liquids and gases.
• Oxygen — ordinary air holds more than enough oxygen to sustain combustion.
• Heat — an ignition source that raises the fuel to the temperature at which it burns.
• Chemical chain reaction — the self-sustaining reaction that keeps the fire going once it has taken hold.

Every method of putting a fire out works by taking one of those four elements away. Water removes heat. A carbon dioxide extinguisher displaces oxygen. Dry chemical powder blankets the fuel and interrupts the chain reaction.

What are the different classes of fires?

Fire classes describe what is burning — and the class determines which extinguisher is safe to use. Canada uses five classes: A (ordinary combustibles), B (flammable liquids and gases), C (energized electrical equipment), D (combustible metals) and K (cooking oils and fats). 1

• Class A — ordinary combustibles such as paper, wood, cloth, rubber and plastics.
• Class B — flammable liquids and gases, including oil, paints and lacquer.
• Class C — energized electrical equipment such as motors, appliances and power tools.
• Class D — combustible metals such as magnesium, titanium, sodium and potassium.
• Class K — combustible cooking oils and fats in cooking appliances.

Using the wrong class of extinguisher can make a fire worse rather than better. Water on energized electrical equipment creates a shock hazard, and water on burning cooking oil can spread the fire instead of stopping it.

What are the main types of fire extinguishers?

Four types of fire extinguisher are described here — water, carbon dioxide (CO2), dry chemical and foam — and each is built around the class of fire it is meant to fight. The descriptions and discharge times below are as published by CCOHS. 1

• Water extinguishers — used on Class A fires; they work by removing heat from the burning material.
• Carbon dioxide (CO2) extinguishers — used on Class B and Class C fires, displacing oxygen with pressurized carbon dioxide. A CO2 unit "has a moderate spray range and last only 10 to 30 seconds. A hard horn attached to the end of the spray tube helps to contain and aim the spray at the target area."
• Dry chemical extinguishers — the most common type, marked for the classes each unit is designed for (an ABC unit puts out Class A, B and C fires). They lay down a powder blanket that separates the fuel from oxygen, and they have a "short to moderate spray range and last only 10 to 25 seconds."
• Foam extinguishers — listed by CCOHS for Class A and Class B fires; Class C is not among their listed classes.

Source: CCOHS comparison table. 1

Two cautions from the same CCOHS guidance. Do not use CO2 extinguishers in confined spaces, because the discharge displaces the oxygen that anyone in that space needs to breathe; CCOHS allows it there only where workers have appropriate respiratory protection. And dry-chemical residue can damage motors, computers and other electrical equipment, so plan for the cleanup as well as for the fire.

Extinguishers also carry a rating that pairs numbers with class letters, such as 2A:10B:C. The letters name the classes the unit is approved for, and the numbers give its relative capacity on Class A and Class B fires.

Those ratings are not just a manufacturer's marking: they appear word for word in provincial rules, which is why the table further down names a 2A:10B:C unit on Quebec buses and minibuses used to transport workers and a 10 BC unit in every British Columbia crane cab.

How do you use a fire extinguisher? (PASS — and when not to fight the fire)

When using an extinguisher, use the PASS system: 1

1. Pull the pin on the extinguisher.
2. Aim the extinguisher.
3. Squeeze the trigger or top handle.
4. Sweep the fire area with the extinguisher's spray until the fire is completely out.

Just as important is knowing when not to fight a fire. Attempt to extinguish a fire only if all of these are true:

• You have been trained on the equipment.
• The fire is small and contained.
• The extinguisher matches the fire class.
• Your exit route is clear and behind you.
• The alarm has been raised.

CCOHS puts it plainly: if you are not confident about your ability to handle the situation — even if you are trained — or you do not have the correct type of extinguisher, do not fight the fire; pull the fire alarm, evacuate the area, and then call the fire department. Its list of times never to fight a fire starts with not knowing what material is burning, and goes on to not knowing which extinguisher to use or how to use it. 1

What are the main hazards of fire?

A fire puts four hazards in front of the people nearby at once.

• Burns and scalds — from flame, from hot surfaces and from steam.
• Smoke inhalation — smoke carries harmful gases that damage the airways and the lungs.
• Carbon monoxide poisoning — carbon monoxide is colourless and odourless, which is exactly what makes it dangerous.
• Explosions — pressure building up in a confined space can cause severe injury or death.

Using an extinguisher carries hazards of its own. The wrong class can spread the fire or cause an electric shock, a CO2 discharge in a confined space displaces the oxygen people need to breathe, and dry-chemical residue damages electrical equipment. The sections on fire classes and extinguisher types above explain each one. 1

What does federal law require for fire extinguishers — installation, inspection and maintenance?

In federally regulated workplaces, fire safety duties come from the Canada Labour Code and the Canada Occupational Health and Safety Regulations (COHSR). Part XVII — Safe Occupancy of the Work Place — requires fire protection equipment to be installed, inspected and maintained in accordance with Parts 6 and 7 of the National Fire Code of Canada (s. 17.3). It also requires a written emergency evacuation plan where more than 50 employees work in the building (s. 17.4), and emergency procedures (s. 17.5). 3,4

The training duty is explicit: every employee must be instructed and trained in the procedures to follow in an emergency and in "the location, use and operation of fire protection equipment" (s. 17.6). Where an evacuation plan exists, employers must also appoint emergency wardens and deputies for each floor (s. 17.7) and instruct and train them in their responsibilities under the emergency evacuation plan and emergency procedures and in the use of fire protection equipment (s. 17.8). 5

One equipment-specific rule worth knowing: motorized materials-handling equipment used for transporting or handling flammable substances must carry a dry-chemical fire extinguisher rated at least 5 B,C (s. 14.12), unless it works only inside a building already equipped under Part XVII. 6

The National Fire Code itself is a model code: federally, the 1995 edition as amended is the one the regulations incorporate (s. 1.2), and the current edition is published by the NRC; provincially it applies through each province's fire code adoption. 7,28

What do the provinces and territories require for fire extinguishers?

Fire safety regulations in Canada work twice over in every jurisdiction: a fire code for the premises, which in most jurisdictions adopts the National Fire Code and in Ontario is a provincial code of its own. The second layer is OHS law for employers, which adds equipment and training duties. The instrument name links to the legislation text and the authority name links to the regulator.

Note the pattern: portable-extinguisher rules reach every Canadian workplace through two doors.

The fire-code door, where the National Fire Code is incorporated federally through COHSR s. 17.3 (the 1995 edition, as amended) and adopted, with variations, by most provinces and territories. Manitoba names its Fire Code inside the OHS regulation, Ontario's Reg. 851 imports "the Fire Code" verbatim, and Quebec adopts NFPA-10 directly.

And the OHS door, which places the equipment and adds the training duties: federally under s. 17.6, in British Columbia under OHSR s. 4.16, in Yukon under s. 1.70(3), in Saskatchewan through the trained fire-safety plan and annual drill, and in Alberta through the mining Part's firefighting-equipment training duty.

What training do workers need on fire extinguishers?

Fire extinguisher safety training is an educational program that gives workers the knowledge to prevent fires and to respond correctly when one starts.

It covers how fires begin and spread, how to recognize the fire hazards present in a particular workplace, which extinguisher suits which class of fire, where the extinguishers are kept and what their limits are, how to operate one, and what the workplace's emergency and evacuation procedures require of each person. 5,21

Who is responsible for training workers and maintaining extinguishers?

Employers are responsible for providing fire extinguisher safety training to their employees. In federally regulated workplaces the duty sits in s. 17.6 of the Canada Occupational Health and Safety Regulations — the instruction-and-training duty quoted in the federal section above. 5

Provincial law also places training on the employer, often through a general duty to instruct workers rather than a rule written for extinguishers. In Ontario, for example, OHSA s. 25(2)(a) requires employers to provide information, instruction and supervision to a worker to protect the health or safety of the worker, and s. 25(2)(h) requires every precaution reasonable in the circumstances to be taken for a worker's protection. 14

The responsibility does not end at booking a course. Employers also have to put the right extinguishers in the right places and match the training to the hazards actually present on site. CCOHS asks that extinguishers be readily accessible and clearly visible, with clear location signs, and sets out the upkeep: a visual inspection of every extinguisher at least monthly, servicing at least once a year or when the inspection calls for it, and a tag and written records of both. 1

Who must be trained to use a fire extinguisher?

Whether fire extinguisher training is mandatory depends on the jurisdiction and on the worker's role. Training is for the people a workplace designates to use an extinguisher, and for general awareness among everyone else. 5,21,10

Several jurisdictions define who must be trained rather than leaving it to the employer. Federally, the s. 17.6 duty reaches every employee. British Columbia requires fire prevention and evacuation instruction for all workers, and yearly retraining for workers assigned to firefighting duties (OHSR s. 4.16). Yukon requires a reasonable number of workers, determined through a hazard assessment, to be trained in the use, limitations, types and location of the extinguishers. Alberta's mining Part requires workers to be trained in the use of firefighting equipment. The table above shows which rule applies where. 5,27,21,10

Fire risk, or the difficulty of getting everyone out, is higher in some workplaces, for example:

• Construction — flammable materials, hot work, and temporary electrical installations.
• Manufacturing — machinery that generates heat and sparks.
• Healthcare — equipment faults combined with large numbers of people who cannot evacuate quickly.
• Hospitality — open flames and heat sources used for cooking.
• Education — many students, staff and visitors to evacuate at once.
• Retail — heating and cooling equipment, electrical faults, and stored combustibles.

Can the training be done online?

Yes — the knowledge part of fire extinguisher safety training can be completed fully online.

One check before you enrol: some workplaces also run hands-on extinguisher practice (live-fire or simulator drills) as part of their own fire safety plan — several jurisdictions require site drills on a schedule. Online training covers the knowledge layer; site-specific drills belong to your employer's plan. Confirm which level your workplace requires. 11,16,10

What does the law require the training to cover?

Canadian OHS law is specific about what fire extinguisher training has to teach. Under the federal COHSR, every employee must be trained in the emergency procedures to follow and in "the location, use and operation of fire protection equipment"; Yukon's regulation phrases the same duty as training in "the use, limitations, types and location" of the workplace's extinguishers. A complete program therefore covers: 5,21

• Fire prevention — the fire prevention and evacuation procedures of your own workplace, which British Columbia requires every worker to be instructed in (OHSR s. 4.16(1)). 27
• The fire classes and what they mean — matching the extinguisher to what is burning.
• Extinguisher types, ratings and limitations — water, CO2, dry chemical, foam, and where each is unsafe.
• Where extinguishers are located — and why locations must be marked and known.
• How to operate one — the PASS technique: pull, aim, squeeze, sweep.
• When to fight and when to evacuate — the decision rules, raising the alarm, and your workplace's emergency procedures and evacuation plan.

British Columbia sets a longer list for workers assigned to firefighting duties, who must be trained by a qualified instructor in fire suppression methods, fire prevention, emergency procedures, organization and chain of command, firefighting crew safety and communications applicable to their workplace (OHSR s. 4.16(2)). 27

Does the law set an expiry date for the training?

There is no statutory expiry date for a fire extinguisher training certificate in any of the fire-protection provisions cited on this page — validity comes from the training program. 11,16,18

One province does set a retraining interval: British Columbia requires retraining at least once a year for workers assigned to firefighting duties (OHSR s. 4.16(3)). 27

Fire safety in Canada already runs on an annual rhythm. Saskatchewan requires a fire drill at least once every 12 months and workers trained in the fire safety plan. Quebec requires rescue and evacuation drills at least once a year. Nova Scotia requires every fire extinguisher to be inspected annually. 11,16,18

Retrain sooner whenever your workplace's hazards, equipment or emergency procedures change — and employers may set their own refresher schedule.

Key takeaways

Know the classes of fire, because the class tells you what is burning. Know which extinguisher is on your wall, what it is rated for, and where it stops being safe to use. Know PASS, and know the moment when the right call is to raise the alarm and walk away instead.

And know that none of this is optional good practice: federal and provincial law already require your workplace to have both the equipment and the training behind it.