Water – Extinguishers are only suitable for Class A fires only and not for Class B, C, or D fires such as burning liquids, electrical fires, or metal fires as it will cause the fire to spread and aggravate the situation.
Foam – Extinguishers are suitable for most fires caused by Class A fires (burning paper) and Class B fires (burning liquid). However, as it essentially a water based mixture, it cannot be used for electrical fires.
CO2 – Extinguisher are meant for Class B and C fires but does not work well with Class A fires because the material usually re-ignites. Although it leaves no harmful residue, it is however a green house gas that contributes heavily to global warming. In addition, it is much heavier compared to the other extinguishers that may not be easily handled.
ABC Dry Chemical – Extinguishers are meant for Class A, B and C fires. They can handle most fires that occur in the household or in a normal office environment. Upon discharge, it will leave a blanket of non-flammable material on the extinguished material that reduces re-ignition. A main disadvantage for this type is that it is corrosive and leaves a sticky residue that must be cleaned up immediately to prevent damage to equipment.
D Powder – Extinguishers are meant for Class D or combustible metal fires only. They are ineffective on all other classes of fires.
Halotron – Extinguishers are meant for Class A, B, and C fires. They are effective and clean that leave no residue upon application, and consequently inflicts little to no collateral damage on equipment in the vicinity of the fire. By far, this is the best choice extinguisher for general usage in the house or in an office.
Wet Chemical – Extinguishers are meant for Class F fires. They are effective against fires involving cooking oils and fats, employing an agent that reacts with burning cooking oil or fat to form a suds-like blanket across the fuel surface, cutting off the fire’s air supply and preventing the release of flammable vapours.
On the different types of fire extinguishers listed above, a good fire extinguisher must indicate clearly the ABC ratings on them. The rating look like “SA/34B.” The higher the number higher the fire fighting power.