The number of fire extinguisher you need depends on your needs. The typical rule for thumb is that a fire extinguisher should be within reach in about 15 Metres.
We recommend having at least one dry powder fire extinguisher (2KG) per level. If you are having a lot of electrical appliance, we suggest that you upgrade to a 3KG fire extinguisher. In additional, if your floor area is more than 1200 sqft per level, you may wish to consider more extinguishers per level. You may refer to our other blog post on the location recommended to store the fire extinguisher.
In Singapore, the fire extinguisher are regulated by the Singapore fire code and are covered under SS578: Use and Maintenance of portable fire extinguishers. The size and type of the fire extinguisher depends on the type of goods and business you are having. In short, the standard will guide you in understanding if your workplace/commercial entity are considered low/medium/high hazard risk where it refers to the amount of combustibles present is such that fires of severe magnitude may be expected.
In addition to the size and type of fire extinguisher, SS578 also regulate that the fire extinguisher should be accessible within 15 metres of travel distance (where travel distance refers to the actual distance that the person have to travel in order to reach the fire extinguisher). Each enclosed space and floor should also have their own fire extinguishers. For large areas or high risk area, you may be required to engage a professional engineer or qualified person to help calculate and submit the fire plan to SCDF.