Fire Load

Definition - What does Fire Load mean?

"Fire load" is a term used to describe the potential severity of a fire within a specified space. It is therefore a form of hazard assessment and is used to determine the level of fire risk that exists within a defined area.

Fire load inspections require the assessment of all materials within the space in order to determine that space's overall flammability. This includes both the material being used in the structure itself and any flammable objects and substances that may be stored in it.

Safeopedia explains Fire Load

A building’s fire load is a calculated value. The specific calculation used varies by region and context. In the United States, the standard for determining fire load during the building design process is NFPA 557. The generic U.S. calculation for determining fire load within a given space uses the metric system, and describes fire load as being equal to the mass in kilograms of all material in that space, multiplied by the value of these materials in calories (kilojoules per kilogram), divided by the area of the space in square meters.


This yields the equation: Fire load = (Mass * Calories) / Area


Various fire safety standards used by occupational safety authorities in the United States and elsewhere are designed to reduce the fire load that exists in areas that are regularly occupied by workers. These include both explicit fire-protection standards, such as those that require certain flammable materials to be kept in storage, as well as standards which are designed to reduce the presence of hazards that may increase fire risks indirectly. OSHA’s housekeeping standards, for example, require workplace safety procedures which simultaneously reduce the risk of workers tripping on items in their environment and limits the amount of potentially flammable material distributed throughout the workplace.


There is no fixed value for when a fire load is "low enough." A workplace's fire load is always somewhat dependant on the material characteristics that are inherent to that type of workplace—a paint factory would be expected to have a larger fire load than a swimming pool, for instance. Whether an employer is keeping a sufficiently low fire load is therefore determined by whether or not their fire load deviates significantly from the load that would be expected within their particular industry.

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