There are many different types of fire extinguisher available. Of these, CO2 models are one of the most commonly seen. These can be identified by a red casing with a black band to denote that they contain carbon dioxide. The contents will also be written on the extinguisher, usually in white lettering. You need to know what sort of extinguisher you have in order to use it correctly.

Before you even reach for the extinguisher is to let everyone else in the area know that there is a fire. If there is an alarm, then us that to alert the building. If there is no alarm, tell someone else to spread the word. Call the fire department as well before you try to put out the fire; and unless you know what to do, leave the firefighting to them.

Next, ascertain whether a CO2 extinguisher is right for this fire. These extinguishers work on most fires: flammable liquids and gases and electrical fires as well as normal fires. The pressure which these extinguishers work at can actually cause damage and small pieces of ice can fly out as well. CO2 extinguishers should not be used around computers because of the possibility of damage. Another kind of fire extinguisher should be used in these situations. These extinguishers are a great choice for electrical and grease fires, since they leave no hazardous residues. Some dry extinguishers do contain dangerous chemicals and all do make something of a mess.

These extinguishers are less than ideal for paper, plastic and cardboard fires as they cannot displace enough oxygen to put out the fire. These extinguishers cannot always cool fires sufficiently to prevent re-ignition. They are very useful, however on electrical fires and oil fires. Do not use these extinguishers on fires of flammable metals, since they can actually increase the rate of the reaction.

If you need a CO2 extinguisher too put out this fire, you can begin by pulling out the plastic tag to release the trigger. Move the discharge horn up to a right angle using your body and then support it with your body as well. Do not hold the horn with your hand – these get so cold during discharge that your hand could become frozen to it. If the fire has become established, do not try to put it out – leave immediately and call the authorities instead. You are not obligated to put out a fire, don't be afraid to leave if it is beyond your ability to control.

CO2 fire extinguishers do make a great deal of noise during use, so be prepared for this. Aim for the base of the flames where the burning material is, rather than at the edges of the flame. Again, if you are unsure of your ability to put out the fire, leave immediately and contact the authorities. With fire, it is always better to be safe than sorry. In case of a fire, you can also use a fire blanket – this works well for putting out small fires before they can spread. Remember to hold the blanket in such a way as to keep your hands covered and leave it on the fire for at least half an hour.

Don't walk on an area where a fire has been, even if it seems to be out – these flames can reignite. Recharge your extinguishers as soon as possible after using them to make sure they are ready in case of future fires. Have your CO2 extinguisher checked regularly to make sure that it is always ready for use.