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Exposures – When to Include Them on Your Incident Report

This NFIRSGram explains when to create an exposure report to accurately document a fire incident in the National Fire Incident Reporting System (NFIRS).

Important points for documenting exposures

  • An exposure is a fire resulting from another fire outside that building, structure, or vehicle, or a fire that extends to an outside property from a building, structure or vehicle.
  • Although the Incident Number permits all properties involved in a fire incident to be related together, the Exposure Number identifies each separate property type involved in the fire. This makes it possible to capture the specific details of the fire in each exposure and to relate all the exposures to the basic incident.
  • In a fire involving exposures, an additional incident report should be completed for each exposure.
  • Each module completed for an exposure should contain the same Incident Number assigned to the original property involved. A separate sequential exposure number is assigned to each exposure. The original incident is always coded “000,” and exposures are numbered sequentially and incremented by 1 beginning with “001.”
  • The Incident Date for each exposure remains the same as that of the basic incident; however, the Alarm Time in Block E1 should reflect the time of each new exposure.
  • Treat similar items in a group as a single exposure (such as a fleet of cars).

Reporting exposure fires is a trouble spot for many fire departments. During fire suppression activities, an exposure is any property that is threatened by the initial property fire, but in NFIRS a reportable exposure is any fire that is caused by another fire. Because of these different definitions, a common reporting error is including on an exposure report an incident where a neighboring property is scorched or the siding is melted, but the property has sustained no fire damage.

When completing an NFIRS report, an exposure is only reported if the initial fire causes another property to catch fire. Reporting melted siding, scorched exterior walls, and water or smoke damage to neighboring properties should not be completed with an exposure report but should instead be documented in the narrative on the initial fire report (e.g., the dollar loss for the nonexposure properties).

Definition of “exposure”

An “exposure” is a fire resulting from another fire outside that building, structure, or vehicle, or a fire that extends to an outside property from a building, structure or vehicle. In the case of buildings with internal fire separations, treat the fire spread from one separation to another as an exposure.

In cases where there are multiple ownerships within a building, such as condominiums, and those properties are not separated by fire-rated compartments, then each condominium, apartment or unit is not a separate exposure. For instance, where you have a fleet of vehicles, such as at a state highway department motor pool, you can count all of these items as a single exposure.

Documenting exposures

When documenting a fire that involves exposures:

  1. Complete a separate incident report, using the appropriate modules, for each exposure.
  2. Enter the Incident Number of the initial fire as the Incident Number in Section A — Key Information.
  3. Enter the Exposure Number, assigning each exposure a separate Exposure Number. On the initial fire, the Exposure Number is 000, with each exposure then numbered sequentially beginning with 001, 002 and so on.

Example: completing the Incident Number and Exposure fields

Section A - Key Information
In the image above, a fire department has begun to enter the key information for the incident. If this was the initial incident, then in the three-digit field for exposure they would enter 000; if, however, this was an exposure report, then they would enter 001 in the exposure field. When you use the same incident number to identify all of the exposures involved in a fire, they become related together in the system with the exposure number identifying each property involved in the fire.
  • Enter the Incident Date of the initial incident; however, in Section E of the Basic Module, the Alarm Date/Time, Arrival Date/Time, and Last Unit Cleared Date/Time should reflect the date and time of each exposure.
  • When a fire involves more than one building, each building fire should be considered a separate fire, with the ignition for all but the original building fire classified as an exposure.
  • Classify Heat Source in Section D2 of the exposure report with one of the 80 series of heat source codes.

Heat spread from another fire (excludes operating equipment)

Heat source codeDescription
Heat from direct flame, convection currents spreading from another fire.
Radiated heat from another fire. Excludes heat from exhaust systems of fuel-fired, fuel-powered equipment (12).
Flying brand, ember, spark. Excludes embers, sparks from a chimney igniting the roof of the same structure (43).
Conducted heat from another fire.
Heat spread from another fire, other.
  1. On the Fire Module of the exposure report in Section E1 — Cause of Ignition, you should check the box for an Exposure Fire, and Section E2 — Factors Contributing to Ignition should be classified with the code 71 — Exposure Fire.
  2. Skip forward to Section G — Fire Suppression Factors and complete the rest of the Fire and other appropriate modules for the report.

Sample coding scenarios for exposure

Scenario 1

A fire department is dispatched to a reported building fire. Upon arrival, they discover that a detached garage is on fire and that two vehicles parked in the driveway are also on fire. The fire department determines that the fire started in the garage and that the two vehicles, both of which are owned by the homeowner, caught fire due to their proximity to the garage.

The fire department:

  1. Creates an initial fire report, incident number 1306001 with an exposure of 000.
  2. Creates an exposure report for each vehicle using the same incident number (1306001). The exposure numbers for the vehicle fires would be 001 and 002.

Scenario 2

A fire department is dispatched to a reported building fire. Upon arrival, they discover a single-story, single-family home on fire, with a neighboring family’s home already beginning to exhibit signs of heat damage as the vinyl siding is beginning to melt. The fire department is able to protect the neighboring home, and all the damage that it suffers is the melted siding on the side that faced the fire building.

The fire department:

  1. Creates an incident report for the initial fire, incident number 1306001 with an exposure of 000.
  2. Includes the damage to the neighboring house in the narrative of the initial report, since the neighboring house did not catch fire.

Have a question about when to create an exposure report?

Please contact the NFIRS Support Center: Monday – Friday between 8 a.m. – 4:30 p.m. ET, at 888-382-3827 or by email at