Materials compliant with the EN45545-2 railway standard

Materials Compliant with EN45545-2 European Railway Standard

Introduction to EN45545-2

EN45545-2 is the European standard for fire protection in railway vehicles, specifying the reaction-to-fire performance requirements for materials and components used in rail transportation applications. This standard harmonizes fire safety regulations across Europe, replacing various national standards like BS6853, DIN5510-2, and NFF16-101. The standard classifies materials into 28 requirement sets (R1-R28) based on their application and defines three hazard levels (HL1-HL3) determined by the vehicle's operating environment.

Hazard Level Classification

HL1 - Standard Hazard Level

• Operating Environment: Vehicles operating in environments with minimum delay stops and immediate safe area access

• Application: Standard vehicles, automatic trains without emergency personnel, double-decker vehicles operating in category 1 environments

• Fire Risk: Lowest level of requirements

HL2 - Medium Hazard Level

• Operating Environment: Vehicles operating in tunnels or elevated structures with side evacuation options

• Application: Sleeping vehicles in category 1, standard vehicles in tunnels <5km, automatic trains in category 2-3 environments

• Fire Risk: Medium level requirements

HL3 - Highest Hazard Level

• Operating Environment: Vehicles operating in tunnels with limited evacuation options or sleeper cars

• Application: Sleeping vehicles in category 3, standard vehicles in category 4 (no side evacuation)

• Fire Risk: Most stringent requirements

Key Performance Requirements

Fire Safety Properties

Materials must meet stringent criteria across multiple parameters:

Flame Spread & Ignitability

• CFE (Critical Flux at Extinguishment): ≥20 kW/m² for HL3 requirements

• Heat Release Rate: ≤60-90 kW/m² depending on application

• Oxygen Index: ≥28% for HL1/HL2, ≥32% for HL3

Smoke Density

• Ds(4): Optical density after 4 minutes ≤150-600 depending on hazard level

• VOF4: Cumulative optical density in first 4 minutes ≤300-1200

• Ds max: Maximum optical density during test

Toxicity

• Conventional Toxicity Index: ≤0.9 for HL3, ≤1.2 for HL1

• Toxic Gas Emissions: Limited CO, CO2, HCN, HCl emissions

Material Categories and Applications

R1 - Interior Surfaces

• Applications: Side panels, partition walls, duct covers, large area materials

• Test Methods: ISO 5658-2 (flame spread), ISO 5660-1 (heat release), ISO 5659-2 (smoke density), EN 17084 (toxicity)

• Requirements: CFE ≥20, MARHE ≤60-90 kW/m², Ds(4) ≤150-600

R2 - Limited Surfaces

• Applications: Smaller interior surfaces, decorative elements

• Requirements: Similar to R1 but with specific application-based thresholds

R3 - Arc Resistant Insulation Materials

• Applications: Electrical insulation components

• Requirements: Enhanced flame retardancy for electrical applications

R4 - Interior Lighting

• Applications: Light covers, diffusers, display screen covers

• Test Methods: ISO 5658-2, EN ISO 11925-2 (ignitability), EN 17084

• Requirements: Transparent materials must meet specific flame spread and smoke density criteria

R6 - Passenger Seating

• Applications: Seat shells, backrests, base shells

• Test Methods: ISO 5660-1 (heat release), ISO 5659-2 (smoke), EN 17084 (toxicity)

• Requirements: MARHE ≤90 kW/m² for HL3, with strict smoke and toxicity limits

R7 - Air Ducts & Exterior Surfaces

• Applications: Under-frame components, external body shells, exterior ducts

• Requirements: Flame spread resistance for exterior applications

R9 - Suspension Parts

• Applications: Drive components, elastomeric tires

• Requirements: Mechanical properties combined with fire resistance

R10 - Floor Coverings

• Applications: Entrance flooring, carpets, linoleum, flocked flooring

• Test Methods: ISO 5660-1 (heat release), ISO 9239-1 (critical heat flux), ISO 5659-2 (smoke), EN 17084 (toxicity)

• Requirements: Minimum HL2 rating, with specific products achieving HL3

R15/R16 - Cables

• Applications: Electrical wiring, cable insulation

• Test Methods: EN 60332-1-2 (single cable), EN 60332-3-24 (bunch cable), EN 61034-2 (smoke), EN 50305 (toxicity)

• Requirements: Flame propagation resistance, low smoke emission

R22/R23 - Interior Seals & Electrical Equipment

• Applications: Seals, gaskets, connectors, circuit breakers

• Test Methods: EN ISO 4589-2 (oxygen index), EN ISO 5659-2 (smoke), NF X70-100-1 & 2 (toxicity)

• Requirements: OI ≥28-32%, low smoke and toxicity

R24/R25 - PCB & Electrotechnical Products

• Applications: Printed circuit boards, electronic components

• Test Methods: EN ISO 4589-2 (oxygen index) or EN 60695-2-11 (glowing wire)

• Requirements: Flame retardancy for electrical applications

R26 - Small Electrotechnical Products

• Applications: Small electronic components (<10g)

• Test Methods: EN ISO 4589-2 (oxygen index) or EN 60695-11-10 (vertical flame test)

• Requirements: Simplified testing for small components

R27 - Light Diffusers & Display Covers

• Applications: Transparent covers for lighting and displays

• Requirements: Specific requirements for transparent materials

R28 - Floor Composites

• Applications: Floor substrates and coverings

• Requirements: Composite floor systems

Material Types for EN45545-2 Compliance

Engineering Plastics

• Polyamide (PA66/Nylon 66): High mechanical strength, heat resistance, UL94 V-0 rating

• Polycarbonate (PC): Transparent, impact-resistant, flame retardant grades available

• PEEK & LCP: High-temperature resistance up to 300°C, used in critical components

• Modified Plastics: Glass fiber reinforced, carbon fiber reinforced, mineral filled grades

Thermoplastic Elastomers

• TPU & TPE: Flexible components, seals, gaskets

• EPDM: Floor supports, sealing elements

• Silicone (VMQ): High-temperature applications

Fluoroplastics

• PTFE, FEP, PFA: Chemical resistance, electrical insulation for cable applications

Composites & Resins

• Unsaturated Polyester Resin: For interior parts, achieving HL3 grade with OI ≥45%

• Epoxy Resins: For structural components

• Phenolic Resins: High fire resistance

Floor Coverings

• Linoleum: Natural materials with renewable content, HL2 certified

• Textile Carpets: nylon or regenerated yarn, HL2 certified

• Flocked Flooring: Lightweight, easy to clean, HL2 certified

Testing Methods

Flame Spread Tests

• ISO 5658-2: Lateral flame spread test measuring CFE

• EN ISO 11925-2: Ignitability test with small flame

• UL94: Vertical and horizontal burning tests

Heat Release Tests

• ISO 5660-1: Cone calorimeter test measuring MARHE (Maximum Average Rate of Heat Emission)

• ISO 9239-1: Critical heat flux for flooring

Smoke Density Tests

• ISO 5659-2: Single-chamber test measuring Ds(4), VOF4, Ds max

• EN 61034-2: Smoke density for cables

Toxicity Tests

• EN 17084: Toxicity testing using FTIRue

• NF X70-100-1 & 2: Tube furnace test for toxicity

Oxygen Index

• EN ISO 4589-2: Measures minimum oxygen content to sustain burning

Certification Process

Material Classification

1. Determine applicable R-set based on application

2. Identify hazard level (HL1-HL3) based on vehicle design and operation category

3. Select appropriate test methods

Laboratory Testing

• Testing at accredited laboratories

• Multiple test methods depending on material type

• Performance against specific thresholds

Documentation

• Fire Certificate Inventory List (FCIL)

• Technical data sheets

• Material safety data sheets

• Compliance certificates

Industry Applications

Railway Interiors

• Seat shells and upholstery

• Wall panels and ceiling covers

• Flooring systems

• Curtains and textiles

Electrical Systems

• Cable insulation and jacketing

• Connectors and junction boxes

• PCB substrates

• Electrical enclosures

Structural Components

• Anti-vibration elements

• Floor supports

• Bracket components

• Guide rails

Exterior Applications

• Underfloor panels

• Bogie covers

• Aerodynamic fairings

• Exterior lighting covers

Sustainability Considerations

Bio-Based Materials

• Materials with renewable content

• Reduced carbon footprint

• Recyclable options

Halogen-Free

• No toxic acid gas emissions

• RoHS and REACH compliance

• Environmentally friendly

Recyclability

• Support for circular economy

• Reduced environmental impact

• Life cycle assessment

Conclusion

EN45545-2 compliant materials represent the highest standard of fire safety for railway applications, combining excellent flame retardancy with low smoke emission and minimal toxicity. The comprehensive classification system ensures that materials are appropriately tested and certified for their specific application, from interior surfaces to electrical components and structural elements. With the increasing focus on passenger safety and environmental sustainability, EN45545-2 compliance has become essential for all materials used in European railway vehicles.