Fire extinguishers are divided into four categories: A, B, C and D. Class A is for regular combustibles, B is for flammables, C is for electrical fires and D is mostly used by chemical laboratories. If you buy a fire extinguisher labeled ABC, it is a multipurpose, dry chemical extinguisher with monoammonium phosphate, and it will put out three out of four types of fires. Though ABC extinguishers tend to leave a mess, the remaining film from the extinguisher ensures the fire doesn't reignite.

On the Other: CO2 Extinguishers

Carbon dioxide extinguishers, which are class BC, are very effective on electrical fires, which are the most common house fires. These extinguishers do not leave a mess and will not damage any electronics you may have to spray. However, CO2 extinguishers are not entirely effective on class A fires, which include plastics. There simply isn't enough oxygen in a CO2 extinguisher to successfully put out class A fires under most circumstances.

Bottom Line

While electrical fires may be the most common type of house fire, they certainly are not the only type. The mess left behind by an ABC extinguisher may be somewhat inconvenient after you've put out a fire, but it's far more important that you are able to successfully put out the fire at all. This makes the ABC fire extinguisher the most ideal and versatile choice for most homes.

Source:

Fire Extinguisher 101

Galt Home

Resource:

National Fire Protection Association