An essential point within the fire safety issue is the combustibility of plastic material used in electrical installations.
SINTEF NBL was asked by DSB (Norwegian Directorate for Civil Protection and Emergency Planning) to investigate whether an electrical defect in a component like for example a wall outlet  is able to cause a fire in the component, and also dispersion to the building.

The reliability of one single component in an electrical installation, for instance an electric outlet, is actually rather high. Despite this, the police have proven that an average of 70 residential fires annual are due to some electrical defect or error in installation material during the period from 1994 to 2004. This is explained with the large amount of, for instance, wall outlet in Norwegian homes.
A study of the statistics from DSB shows that this number has a rising tendency from 60 fires in 1995 to approximately 80 in 2004.

The survey show huge uncertainty when it comes to establishing which processes that cause fire in electrical installations, and that we need more research into the matter.

For more information on this subject, read the reports (in Norwegian)NBL A06121 and NBL A06122.