Causes of kitchen fires

According to the experiences of an insurance company, all property losses for restaurants above 100 000 euros are due to fires.

Approximately 40% of all restaurant and hotel fires originate from the kitchen where about 19 % of the fires start at the stove. According to the Swedish Civil Contingencies Agency, there are around 270 restaurant and hotel fires every year, and about 30 of those are caused by arson!

In addition to the risk of injury, the cost of property and material damage is significant, often more than 50 000 euros per restaurant. It also leads to further expenses due to loss of revenue while the restaurant is closed for reparation. The insurance may, or may not, cover this lost revenue.

Liquefied petroleum gas (LPG or LP gas or propane) must be removed at an adjacent fire due to the risk of the fire spreading. A fire that starts in adjacent premises threatens to take off if it manages to ignite the grease in a polluted kitchen duct.

Common causes of kitchen fires

  • Too high temperatures in the deep fryer
  • Highly flammable vegetable oils
  • Old, more flammable oil, in the deep fryer
  • Fat deposits in the flue and ventilation ducts
  • Misaligned sprinklers due to equipment on wheels being moved around
  • Malfunctioning sprinklers due to the fusible links being clogged by grease

What is required for a fire to occur?

It might be obvious but there are three requirements for a fire to occur; fuel, oxygen (air) and heat.

Remove one or several of these requirements and a fire can be avoided.

All these factors are, at varying levels, present in a kitchen.

Fire extinguishing systems

The systems available on the market are mainly based on “suffocation”, i.e. oxygen removal. This is done by spraying a foaming solution, a powder or carbon dioxide at the fire to shut out the oxygen supply. A secondary benefit is that the solution is supposed to cool the fuel, removing some of the heat.

Preventive measures against the fire spread

One of the requirements for a fire to keep burning, when the heat and the oxygen are present, is enough fuel. As long as there is fuel in such a conditions, the fire will keep burning.

A part of the solutions for removal of grease in the system aims to reduce the occurrence of grease accumulations in the parts of the ventilation system that are exposed to fire hazards, for example, the flue.

Flues and fire resistance

Stainless steel ducts are expensive, but also the safest in terms of fire prevention. This is because of the high temperature resistance of stainless steel, which allows it to withstand the high temperatures that occur, for example, during a fire spreading through fat deposits in the ventilation duct. Read about fire tests done by IMKANAL2012. A kitchen exhaust duct with a built-in purification system, such as ozone treatment or UV-lamps, poses a lower fire hazard (to class 2B), which may allow for cheaper materials than stainless steel to be used (depending on your country’s regulations and recommendations regarding fire prevention). Additionally, the need for duct cleaning decreases because grease particles are continuously removed from the exhaust air.