EN 13501
European standard for fire-protection classification of building materials.
The standard EN 13501 establishes the testing procedures and classification criteria for the fire behaviour of construction products within the EU. It defines fire-behaviour classes from A1 (non-combustible) to F (easily ignitable) and regulates the determination of ignitability, heat release and smoke development. Compliance with the standard helps in selecting suitable materials for staircases and other building components.