What Does
Fire Load Mean?
Fire load refers to the potential severity of a fire within a specific area.
A given location’s fire load is determined by an inspection in which all materials within the space are assessed for their flammability. This includes the material components of the structure itself as well as the items stored in it.
Safeopedia Explains Fire Load
The formula for calculating a fire load varies around the world. In the United States, the NFPA 557 standard specifies how to calculate the fire load of a building during its design process.
Based on this standard, the fire load is determined by multiplying the mass (in kilograms) of all the materials in the space by the calorie value of those materials (measured in kilojoules per kilogram). The result is then divided by the area of the space (in square meters).
In simplified form, the equation is:
Fire Load = (Mass x Calories) / Area
While the fire load calculation can be performed for an entire workplace or jobsite, it can also be used for smaller sections of a facility. For instance, a study of fire loads in high-rise residential buildings found that the fire load of a living room averaged around 310 to 379 MJ/M² while the fire load for a bedroom was higher, at approximately 518 to 650 MJ/M².
What Is an Acceptable Fire Load?
There is no fixed value for when a fire load is “low enough.”
Not only that, but a workplace’s fire load will be somewhat dependent on the materials needed for the type of work being done. A paint factory, for instance, will certainly have a higher fire load than a swimming pool. Whether an employer is keeping a sufficiently low fire load will depend in part on whether their fire load deviates significantly from what would be expected within their industry.