The passengers must be able to escape danger. This is assured by operating characteristics and vehicle construction. Trains are designed and constructed so they can still be driven for a specific time in case of fire, capable of continuing out of a tunnel or across a bridge. Corresponding escape routes must be in place and usable.
Above all, fire must be kept from starting at all costs. If a fire does occur, both flame and the resultant smoke must be kept from spreading. If fumes develop, these must not have any detrimental effects to occupants, nor may smoke density hinder orientation to escape routes.
For these reasons, painstaking attention is given to the use of high-quality materials that meet the above requirements from the earliest stages of conception and development.
So these required material properties could be recognized and compared, the decades-old national European standards (DIN 5510-2, NF F 16-101/-102, BS6853, and others) were harmonized and adopted in European standard EN 45545. EN 45545 took legal force March 2013, and must be applied!