Reducing the Risk of Fire on Your Farm - Leading Causes of Farm Building Fires

Table of Contents

  1. Misuse of Ignition Source or Igniting Equipment
  2. Design, Construction or Maintenance Deficiency
  3. Other Factors that Contribute to the Impact of Fires

The Office of the Fire Marshal manages a database on all fire and explosion occurrences in Ontario. Data reported by fire departments for 2004 – 2007 were analyzed for occurrences involving farm buildings to identify common causes and what can be learned to reduce them. Figure 1 shows a very large swine facility after it was destroyed by fire, in less than one hour.

Aerial photo of a large swine operation that was completely destroyed by fire in less than one hour.  All that remains standing are feed bins and a drive shed in the background.

Figure 1.0. This large swine barn was completely destroyed by fire. (Photo credit: P. Stolk, Farm Mutual Reinsurance Plan)

While the sources of many fires are undetermined due to significant fire damage, there are three leading causes of identifiable farm fires, as reported by fire services.

Mechanical/electrical failure
  • short circuit or ground fault in electrical equipment
  • failure of the built-in automatic controls in mechanical equipment or system
Misuse of ignition source or igniting equipment
  • improperly discarded smoker's material
  • ignition source left unattended
  • smoking where flammable vapours are present
  • improper use of extension cords (e.g. overloaded circuit, multiple strings in sequence)
Design, construction or maintenance deficiency
  • improperly constructed building feature or system
  • improperly installed object such as a heating appliance that is too close to combustible building features
  • improper maintenance such as failure to remove accumulation of combustible dust or debris, which is then ignited by heating appliances, process equipment or electrical equipment
  • faulty product design causes a fire even when the product is installed and used correctly

Mechanical/Electrical Failure

The insurance industry, in association with the Electrical Safety Authority (ESA), reviewed additional information on mechanical and electrical failures leading to barn fires. They identified the corrosive environment found inside confined livestock barns as the leading cause of degradation or failure of electrical equipment. The degradation is typically corrosion of the exposed metal components (e.g. wires, connections, etc.). The corrosion increases the resistance at these points causing a reduction in the flow of electricity through the circuit. The increased resistance results in more of the electrical energy being converted to heat (Figures 1.1 and 1.2). As the corrosion levels continue to increase, the heat generated rises to the ignition temperature of the materials surrounding the equipment. The decay can occur over a short period of time. Evidence of corrosion has been observed in barns less than five years after construction.

The image on the left shows a thermographic picture (uses colour to indicate different temperatures in the electrical; equipment) to show that the increased electrical resistance in the receptacle box from corrosion is being converted to heat and hence a fire hazard. The image on the right shows a close up picture of the same electrical receptacle (ceiling mounted) in the  livestock barn.

Figure 1.1. Thermographic picture of an electrical receptacle in a livestock barn. (Photo credit: R. Drysdale, Farm Mutual Reinsurance Plan)

The image on the left shows a thermographic picture (uses colour to indicate hot spots) to show the hot spots on an electrical panel in a livestock barn.  The image on the right is a normal picture of the same electrical panel in the livestock barn.

Figure 1.2. Thermographic picture of an electrical panel in a livestock barn. (Photo credit: R. Drysdale, Farm Mutual Reinsurance Plan)

Misuse of Ignition Source or Igniting Equipment

A commonly reported cause of fires in farm buildings is the misuse of equipment (i.e. arc welders, cutting torches or grinders) in the presence of combustible materials or gases without the proper safeguards. The careless use of smoker's materials (i.e. cigarettes, matches, pipes) continues to be a common cause of fires. Fires reported in this group reflect human error and are preventable with best practice operating procedures (Figure 1.3).

Picture of a man, inside a barn, using a grinder on a piece of metal.  The person is grinding over two bales of hay which are combustible materials.  This activity should be done outside the barn and away from anything that might catch fire.

Figure 1.3. Grinding operation taking place in the presence of combustible materials. Use this type of equipment outside the barn and away from combustibles, or put safeguards in place to reduce the risk of accidental ignition. 

Design, Construction or Maintenance Deficiency

Improperly designed, installed or maintained building systems are another common cause of farm building fires. This includes heating equipment, lighting systems, process equipment and electrical distribution. For example, heat shields for a suspended radiant tube heater may become displaced with the use of a high pressure washer. Without the shields properly in place, the underside of the ceiling becomes too hot and increases the potential for ignition and fire (Figures 1.4 and 1.5). Although the design and installation of the equipment is correct, a maintenance deficiency would be identified as the cause of the fire.

Picture of a radiant tube heater, suspended from the ceiling of the barn, with a section of its heat shield missing.  As a result of the missing heat shield, there is evidence of charring on the wood ceiling.

Figure 1.4. Radiant tube heater with heat shield displaced. Note charring on the ceiling. (Photo credit: R. Drysdale, Farm Mutual Reinsurance Plan)

Picture of a u-joint of a radiant tube, suspended from the ceiling, with a section of its heat shield missing above the joint.  The image shows how close the section with the missing heat shield is to the wood ceiling and an electrical conduit (all combustible).

Figure 1.5. Radiant tube heater lacking heat shield. Note close proximity to combustibles (wood ceiling and conduit). (Photo credit: R. Drysdale, Farm Mutual Reinsurance Plan)

Other Factors that Contribute to the Impact of Fires

In addition to looking at the causes of fire, it is important to review other factors that contribute to fire growth and the magnitude of the losses. An ignition source must be close to combustible materials for fire to start. Combustible materials cannot be totally avoided on the farm, but reducing their use in construction and establishing good housekeeping practices goes a long way in reducing fire growth. The use of fire compartments is an effective design strategy to contain a fire and prevent total building destruction. To be effective, keep fire compartments in good condition, including the proper operation of fire doors. Early detection and fire response are key to reducing the magnitude of farm fires. Many of these concepts and recommended considerations are covered in this guide.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 20 November 2012
Last Reviewed: 20 November 2012