What is the difference t between the fire extinguisher CO2 and FM200?

FM-200® and CO2 are two of the most effective forms of fire suppression, and in facilities from power plants to clean rooms, they will work when water is just not an option.

FM-200 need smaller storage area.

Apart from what others have answered here , i would like to add FM200 is an automated fire suppression system whereas co2 type is not. Recently i came across one more system where oxygen level @data centers or other secured places are being controlled(14-15%)to avoid fire. its called CAP9 system.

FM200 is1,1,1,2,3,3,3 heptafluoro propane. It's in the chemical family of halons, which suppress fire by interfering catalytically with combustion reactions. They can do this at relatively low concentrations which do not constitute a hazard to humans. This means that the site of a fire can be checked out by people without protective gear without the threat of re-ignition.

Carbon dioxide just displaces oxygen. If CO2 is in sufficient concentration to suppress fire, the area will be off-limits to human without breathing gear. This causes some problems with safety checks afterward.

In addition to the reported answers, I would like to add that the CO2 is less expensive than the FM200, so CO2 is used for fire suppression mainly for electric rooms where the is no continuous presence of people, whereas the FM200 Is used for other hazardous area that may be occupied and where sensetive equipment are installed such as data centers.

Another alternative to FM200 is the INERGEN. The INERGEN Fire Suppression System protects enclosed areas where people may be present, fire may strike day or night, and damage from conventional agents cannot be tolerated.

There is also the HALOCARBON Clean Agent System that quickly suppresses fires and protects sensitive equipment without causing harm to people or the environment. The system is especially suited to suppress fires in areas where an electrically non-conductive medium is required, where electronic systems cannot be shut down in an emergency, where cleanup of other agents poses a problem, and in normally occupied areas that demand a non-toxic agent.

Regards

FM CAN WORK IN VERY LOW TEMPRATURE ( - DIGREE CELCIOUS ) BUT CO2 CAN NOT