Motor vehicles contain a number of components that can burn if subjected to a large enough ignition source. These include seating, headlining and carpeting. Several test methods have been developed by the motor industry to assess burning behaviour. Materials used within the passenger compartment need to have a degree of burn resistance so that occupants have time to escape the vehicle in the event of a fire.

In some cases manufacturers have also developed their own specifications based on these standards. FMVSS 302 is a mandatory requirement for all materials used in the interior of motor vehicles sold in the USA, and the BS and ISO standards are generally specified for other markets, although not always as a legal requirement. The standards are not only applicable to passenger cars, but also lorries, trucks and coaches as well as agricultural and forestry vehicles.

Testing is carried out in a small combustion chamber typically 37cm long by 20cm wide and 35cm high, incorporating holes in the floor to allow air ingress and a ventilated clearance at the top. A glass observation window enables the tester to monitor the progress of any ignition, after the samples have been inserted via a hinged door on the side – samples of material measuring 356mm x 100mm are mounted horizontally in a U-shaped holder, which is slid onto rails within the chamber. When fully inserted, the end of the sample is situated above a Bunsen burner with a 10mm tube diameter, exposing the free end of the material under test to a small natural gas flame. Measurement of burning time is completed when the flame either extinguishes or completes its travel to the last measuring point. The burning rate per minute can then be calculated.