HOW TO CHOOSE A FIRE EXTINGUISHER
Generally speaking, in case of risk of class-A, -B and -C fire, and in case there are electrical appliances, the choice should be a multi-purpose (ABC) dry chemical fire extinguisher. In case of risk of class-B and -C fire, a regular dry chemical fire extinguisher is more effective. When there are electrical apparatus that could be damaged by chemicals, a carbon dioxide fire extinguisher is a better choice; on the other hand, these fire extinguishers are not suitable for class-A fires.
Once the number and type of fire extinguishers are decided, these must be places according to the characteristics of the place. If a room contains people, the fire extinguisher should be inside it, if a room is small and does not contain people, or they stay in the room for a short time doing low-risk activities (waiting halls, hospital rooms, hotel rooms, etc.), the fire extinguisher should be put outside of it. Fire extinguishers should be put both inside and outside a large room with a high risk of fire. Obviously, they are placed near the doors and near the most dangerous areas of the room.
In storages, fire extinguishers should be placed along the main aisles, unless it is an automated storage, in which case they will be put at the end of the aisles, out of the shelves. The fire extinguishers should always be easily accessed, clearly visible, protected from impacts and marked by a sign.