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Documenting Equipment Involved in Ignition When the Heat Source is Operating Equipment

Posted: Dec. 17, 2020

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This NFIRSGram explains how to accurately code equipment involved in ignition when a fire department documents that operating equipment was the heat source responsible for the ignition of the fire.

Heat Source (Section D2)

In Section D2 of the Fire Module, fire departments should enter a two-digit code that best describes the type of heat source that ignited the fire. This information, combined with other factors in the ignition sequence, permits analysis of how fires start and is of direct interest for fire prevention efforts.

Options to complete Section D2 include heat sources, such as operating equipment, smoking materials, explosives or fireworks, and hot or smoldering objects. If it is known that the heat source that ignited the fire was from operating equipment, fire departments should enter one of the following four codes:

Operating Equipment

  • Code 10 – Heat from operating equipment, other.
  • Code 11 – Spark, ember or flame from operating equipment.
  • Code 12 – Radiated or conducted heat from operating equipment.
  • Code 13 – Electrical arcing.

Equipment Involved in Ignition (Section F1)

Later in the Fire Module, in Section F1, fire departments should enter a three-digit or three-letter code that indicates the piece of equipment that provided the principal heat source to cause ignition. Analysis of the equipment involved in ignition is useful for improving product safety and preventive maintenance.

In addition, it is just as important to know the kind of equipment that was used improperly as it is to know the kind of equipment that malfunctioned. Misuse can be the direct result of the way the equipment is designed and constructed. When involved in ignition, equipment information provides an important part of the causal data. Equipment involved in ignition can be compared to other causal data to determine if the equipment was (or was not) operating properly.

Options under Section F1 in the Fire Module include equipment, such as cooking, kitchen, commercial, medical, garden and other household equipment. If code 10, 11, 12 or 13 was previously entered in Section D2 (Heat Source) to indicate that operating equipment was the heat source involved in the ignition of the fire, fire departments should enter into Section F1 one of the following:

A three-digit code (codes 000 to 897) that names the specific piece of equipment involved.


The three-letter code “UUU” to indicate that an undetermined piece of equipment was involved in ignition.

If your fire department entered code 10, 11, 12 or 13 into Section D2 (Heat Source), your fire department is indicating it is known that operating equipment was the heat source involved in ignition. As a result, your fire department should never subsequently enter the three-letter code “NNN” in Section F1 to indicate no equipment was involved in ignition.


For more information about NFIRS, 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