Difference Between Dry Chemical & Carbon Dioxide Fire Extinguishers

Dry chemical extinguishing agent used on class A, B, and C fires. ABC dry chemical is usually a mix of monoammonium phosphate and ammonium sulfate, the former being the active one. The mix between the two agents is usually 40–60%, 60-40%, or 90-10% depending on local standards worldwide.

Fire extinguishers filled with carbon dioxide or another non-conductive agent are appropriate for putting out electrical fires. Class C fire extinguishers are made for putting out fires originating from appliances, wiring, circuit breakers and outlets. Though mainly used for electrical fires, these fire extinguishers can also be used to put out fires from combustible liquids. However, they should never be used to put out fires from wood or paper unless there is no other alternative.

Caution to Use:

ABC dry chemical is inappropriate for chlorine or oxidizer fires. The resulting chemical reaction can cause an explosion or a breakdown of the chemicals releasing toxic gases. 

There are a few things to keep in mind when using fire extinguishers. Carbon dioxide fire extinguishers are under considerable pressure. They will expel their contacts in about 20 seconds whereas it takes a full minute for dry chemical extinguishers to expel their contents. One danger is that carbon dioxide fire extinguishers have the ability to spread the burning contents around the area. Also, as the carbon dioxide expels, it will rapidly cool the handle, and can cause frostbit to the handler if caution is not taken. Dry chemical fire extinguishers, though effective at putting out electrical fires, can cause damage to electrical components when they are exposed.

Top Most