Reaction to fire: how are the materials used in car interiors tested?

A vehicle has components that, if subjected to an ignition source, can cause a fire in the car, putting its occupants at risk.

For this reason, materials used in the passenger compartment - such as roof linings, seats, carpets, seat belts or even structural components such as plastics or foams - have to comply with certain requirements regarding their fire behavior.

Safety standards such as FMVSS 302 (USA) and ISO 3795 are similar standards, which were developed to help reduce deaths and injuries to vehicle occupants when a fire occurs, especially those originating inside, caused, namely, for matches and cigarettes.

Some manufacturers have also developed their own specifications based on these standards, which apply not only to passenger cars, but also to buses, lorries, and agricultural and forestry vehicles.

The main objective of the tests foreseen in these standards is to study the effects of the application of a flame on the component materials of vehicles, through the determination of the horizontal combustion velocity.

For most applications, a burn rate of no more than 100mm per minute is acceptable, although some manufacturers have tightened the requirements to stipulate slower burn rates, or still test materials after an aging time.

These manufacturers have the support of INEGI for this purpose. The Smoke and Fire Laboratory performs, among others, the following tests to determine the horizontal combustion rate of components from the automotive industry: