Know Your Fire Extinguishers

­fire extinguishers

» download pdf version: extinguisher chart

You are not required to put the fire out – but if you attempt to extinguish a fire then you need to know your fire extinguishers. Only attempt to put a fire out if you have a clear exit from the room. Do not turn your back on a fire and keep your exit from the room open and accessible at all times. Extinguishers will work for approximately 30 seconds – if you have not put the fire out in that time – leave the area immediately. Once you leave a burning room, do not re-enter. Close the door to a room with a fire. Leave the door unlocked as the fire department will need to enter. If you know the type of fire and contents of the room, please advise the Chief Fire Warden for the building or the Fire Department personnel.

Types of Fires:

There are three types of fires listed on the above diagram; not all extinguishers can be used on each type of fires.

Type A fires are the ordinary combustible materials such as wood, paper, cloth, etc…

Type B fires are flammable liquid fires such as gasoline, paints and solvents, alcohols, acetone, etc..

Type C fires are electrical fires.

There is a fourth type of fire not listed on the above diagram – Type D fires are flammable solids. When labs have flammable solids, a special type of fire extinguisher is required. You must contact  Fire Safety at Facilities & Operations to advise that your lab has flammable solid so they can provide you with the appropriate extinguisher.

The type of fire will determine the type of extinguisher that can be used. In many university labs, Fire Safety have supplied the multipurpose dry chemical extinguishers because they cover all three types of fires.

Water Extinguishers

Water extinguishers are good for Type A Fires only. Type A fires are wood, paper or cloth fires. You cannot use a water extinguisher for a Type B fire,(flammable liquids), as flammable liquids are lighter than water and will float on the surface of the water. This will simply aid in the spread of the fire. You cannot use a water extinguisher on a Type C fire, (electrical fire), because you run the risk of receiving an electrical shock. Water is an electrical conductor so as the water spreads out, the chance of electrocution increases.

There are special water mist extinguishers that work well on a Type A & C fires. Such extinguishers are ideal for Class A fires where a potential Class C hazard exists. The misting nozzle provides safety from electric shock and reduces the scattering of burning materials. This type of extinguisher is not found in labs because the U of A stocks labs with a multipurpose dry chemical extinguisher, a type of extinguisher that works best for mixed fires.

CO2 Extinguishers:

A CO2 extinguisher is not a good choice for a Type A fire, (wood, paper, cloth), because of the force of the CO2 gas being expelled from the extinguisher. When this type of extinguisher is used on a wood, paper or cloth fire, the burning items are blown around the room by the force of the CO2 gas, thereby aiding the spread of the fire. Secondly, a Type A fire will usually re-ignite as soon as the CO2 gas dissipates.

The CO2 extinguisher works well on a flammable liquids or an electrical fire – Types B or C fires. They work well on an electrical fire in that they do not leave a messy residue on delicate electrical equipment such as a dry chemical extinguishers would. The CO2 displaces the oxygen at the surface of the fire, effectively smothering the fire. However, the fire can re ignite once the CO2 gas dissipates if the ignition source has not been removed.

A CO2 extinguisher has a wide nozzle that locks into place. Do not hold onto the nozzle when firing the extinguisher, this nozzle will get very cold as the CO2 gas is expelled; CO2 gas has a temperature of minus 66C. If you are holding onto the nozzle you will receive a cold burn.

Dry Chemical Extinguishers:

The multipurpose Dry Chemical Extinguisher for a Type A,B,C fire is what you will find in most university laboratories that contain chemicals. These extinguishers have the most range of compatibility with items found in a lab and are good for most types of fires. A Type BC fire extinguishers contain sodium or potassium bicarbonate and a Type ABC fire extinguishers contain ammonium phosphate. They have an advantage over CO2 extinguishers in that they leave a blanket of non-flammable material on the extinguished material which reduces the likelihood of re ignition. However, they make quite a mess and the fine powder will irritate the throat and lungs.

The contents of these cylinders can pack down over time and when a person goes to use them they may not fire. If this happens, turn the cylinder over and rap it sharply on the top to loosen the compacted powder inside. Then try firing the cylinder again. If the cylinder will not fire – leave the area immediately.

All fire extinguishers have fire ratings stamped on them. You should familiarize yourself with this rating. For example, a dry chemical cylinder may have 2A, 10 BC stamped on it; this means that the contents of the cylinder are enough to fight 2 square meters of a Type A fire or 10 square meters of a Type B or C fire. Higher numbers mean more firefighting power.

Type D Fires; Flammable Solids:

Flammable Solids – requires a Class D Extinguisher

There is a fourth type of fire not listed on the above diagram. Type D fires are flammable metal fires such as magnesium, potassium, sodium titanium, as well as alkyllithiums, Grignards and diethylzinc. Type D fires burn at high temperatures and the metals will react violently with water, air, and/or other chemicals. This type of fire requires special metal/sand extinguishers. They work by simply smothering the fire with powdered copper metal or sodium chloride (NaCl). You should have an approved class D extinguisher if you have flammable metals in your lab area. The type of class D extinguisher depends upon the type of flammable metals you have; you will require the copper extinguishing medium for lithium and lithium alloy metals; the sodium chloride extinguisher works better for fires involving magnesium, sodium, potassium, uranium and powdered aluminum.

Always advise Fire Safety at Facilities & Operations if you have used any University fire extinguisher or if the seal has been removed.


 Fire Extinguisher Training:

Yearly fire extinguisher courses are available through the Facilities & Operations, Fire  Safety Division during the months of May, June, July, August & September. The dates and information regarding the fire extinguisher courses are posted on their web site,  Sign up for their course if you would like to learn how to operate a fire extinguisher effectively. Such training can be invaluable to you at home or at work in the event of a fire emergency. You should never attempt to put a fire out until you have been trained in the proper use of a fire extinguisher.

Remember – if you cannot extinguish the fire within 30 seconds
– get yourself out!

Fire & Life Safety Division: Office of EH&S

The U of A, Facilities & Operations, Fire Safety link can be found at: Office of the Vice President

 Fire Extinguisher Courses:

The Fire Safety Division at Facilities & Operations, offer a Fire Extinguisher Course once a year in late May or early June every year. This allows Un­iversity personnel the chance to learn how to use the different types of extinguishers found on campus and how to effectively put out a fire. Check their website at: Fire Extinguisher Course to find out when they offer their next course.

 Fire Extinguisher Training

Fire Evacuation Procedures

  1. Activate fire alarm pullstation…(can be found along exit route)
  2. Close door(s) in fire area…
  3. Evacuate fire area and building…
  4. Call 911 and give your name, location and nature of the fire…
  5. Meet fire department at main entrance.

Note: Only attempt to extinguish the fire if no danger exists and the first three steps have been taken.

  Emergency Contact Numbers on Campus



Emergency Procedures

Fire Drills:

There is one fir­e drill every year across campus. This drill is held at 15 minutes to the hour to minimize disruption to classes and is usually held early in the school year.

Fire Alarms:

Fire alarms will sound for a fire, a large or very toxic chemical spill or a bomb threat. You are to leave the building immediately and use the nearest exit. You are not to go back to your office or stop off at a washroom. DO NOT USE THE ELEVATORS WHEN THE FIRE ALARM IS SOUNDING. Do not re-enter the building until the “all clear” signal has been given.

Non Ambulatory Persons:

Should go to a stairwell area and wait there for help. Be sure that a fire warden knows you are there. They will convey your location to the chief fire warden and that person will have the emergency response team assist you out of the building. DO NOT ATTEMPT TO USE THE ELEVATORS.

If you detect a fire:

Sound the fire alarm. The pull stations are located near all exits and stairwell exits to the buildings. Inform the fire wardens of the location of the fire and the type of fire if you know.

Fire Evacuation Procedures:

  1. Activate fire alarm pullstation…(can be found along exit route)
  2. Close door(s) in fire area…
  3. Evacuate fire area and building…
  4. Call 911 and give your name, location and nature of the fire…
  5. Meet fire department at main entrance.

Note: Only attempt to extinguish the fire if no danger exists and the first three steps have been taken.

Fire Extinguishers:

Are found in all labs and many offices. There are also extinguishers near the exits to the buildings. You should only attempt to put the fire out if you know how to use an extinguisher properly and are not being cut off from your escape route. You only have 30 seconds to put the fire out, after that you MUST leave.

Emergency Routes:

Instructors or TA’s should check for the nearest fire escape route from their classrooms and bring this information to the attention of their class as part of their introductory talks. Remind all personnel not to return to their offices or to stop off at washrooms should the fire alarms sound. Also remind non-ambulatory personnel to go to a stairwell area and wait; report this information to a fire warden. If possible, have someone stay with the non-ambulatory person. NO ONE SHOULD ATTEMPT TO USE AN ELEVATOR WHEN THE FIRE ALARMS SOUND. Personnel on crutches should be reminded to allow the main flow of traffic to go ahead of them down the stairs and to wait until the stairwells have cleared before descending – unnecessary falls have happened when they attempt to go down the stairs during the initial evacuation.

If your clothes catch on fire, you must STOP, DROP and ROLL to put the fire out!