Fire-Retardant Silicone Sheet EN 45545-2
Solid VMQ silicone sheet with an enhanced fire-resistance formulation, low smoke emission and low toxicity. Tested and certified to EN 45545-2 version 2020. Compliant with requirement sets R22 and R23 at all three hazard levels: HL1, HL2 and HL3. Available in the full range of hardnesses (30 to 85 Shore A) to cover everything from soft door gaskets to rigid mechanical support parts.
Standard EN 45545-2 sets the fire-performance requirements for materials used in European railway vehicles. Each component must be tested according to its use category (R — Requirement set) and meet a hazard level (HL — Hazard Level) that depends on the operational category of the vehicle and the type of infrastructure. Level HL3 is the most demanding: it applies to vehicles that operate in tunnels and underground stations, where evacuation is more difficult and the consequences of a fire are more severe.
Fire-retardant silicone Series 16 is formulated specifically to meet these requirements. The compound incorporates flame-retardant additives that provide self-extinguishing behaviour, drastically reduce smoke emission (Ds max from 45 versus the HL3 limit of 300) and keep the toxicity of combustion gases well below the regulatory thresholds (ITCPNL 0.06 versus the limit of 1.2). All this without sacrificing the fundamental mechanical properties of the silicone: Series 16 maintains tensile strength of up to 9 MPa, elongation of up to 850% and tear strength of up to 25 kN/m depending on hardness.
Available as solid sheet for cutting flat gaskets, washers and seals, and in extruded and moulded form for profiles, O-rings and complex-geometry parts. For applications requiring cellular fire-retardant material (door gaskets, compressible seals), we supply Series 33 in sponge form.
Do you need HL3 or is HL1/HL2 sufficient?
The hazard level is not a choice — it is determined by the operational category of the vehicle per EN 45545-1. HL1 for vehicles on open track with no underground infrastructure. HL2 for vehicles with access to short-duration underground infrastructure. HL3 for vehicles that regularly operate in tunnels and underground stations (metro, urban commuter rail). Series 16 meets all three levels at R22 and R23, so it can be specified for any European railway project without restriction.
Which format do you need?
Locate your railway application and the recommended format.
| Requisito | Formulación | Serie | Proceso |
|---|---|---|---|
| Flat flange gasket on on-board equipment | Solid Series 16 | 60 ShA · 2–4 mm | Die-cut to drawing |
| Interior carriage fixing washer | Solid Series 16 | 60 ShA · 1–2 mm | Die-cut to drawing |
| Carriage door seal (compressible) | Cellular Series 33 | Sponge · 6–10 mm | Custom cut + adhesive |
| Window sealing profile | Extrusion Series 16 | 50–60 ShA · custom section | Continuous extrusion |
| O-ring for on-board pneumatic system | Moulding Series 16 | 60–70 ShA | Compression moulding |
| Anti-vibration mount | Moulding Series 16 | 70–85 ShA | Compression moulding |
| Railway HVAC duct sealing cord | Extrusion Series 16 | 50 ShA · round cord | Extrusion + ring vulcanisation |
| Electrical equipment cabinet gasket | Solid Series 16 | 60 ShA · 2–3 mm | CNC die-cut to drawing |
| Train interior panel seal (compressible) | Cellular Series 33 | Sponge · 3–5 mm | Custom cut + adhesive |
| Door closure damper | Moulding Series 16 | 35–50 ShA | Compression moulding |
Sheet, extrusion and moulding — all EN 45545-2 certified
Solid sheet — cutting and die-cutting
Fire-retardant solid silicone sheet in roll or cut piece. The base material for manufacturing flat gaskets, washers, flange seals and custom die-cut parts. Thicknesses from 0.5 to 12 mm, hardnesses from 30 to 85 Shore A. The most direct format for railway maintenance: the operator receives the sheet and cuts the gasket on site, or receives the die-cut part ready to install.
Extruded profiles — Series 16 extrusion (PEQ)
Continuously extruded fire-retardant silicone profiles: round, square, rectangular, trapezoidal and special-section cords. For linear sealing of doors, windows, frames and panels. End vulcanisation to create closed ring or frame joints. The EN 45545-2 test results for extrusion (PEQ) achieve HL3 with an oxygen index of 32.7%.
Moulded parts — Series 16 moulding (PMQ)
Complex-geometry parts manufactured by compression or injection moulding. O-rings, seals, mounts, dampers, technical parts to drawing. The EN 45545-2 test results for moulding (PMQ) are even better than those for extrusion: oxygen index 35.1%, Ds max 45. This is because the moulding process allows greater compound homogeneity.
Fire-retardant sponge — Series 33 (cellular)
For seals requiring compressibility (doors, panels, enclosures), we supply Series 33: closed-cell cellular silicone with enhanced fire resistance. Compliant with EN 45545-2 R22/R23 at HL1 and HL2. Platinum cure. See the dedicated sponge sheet page for more details.
From 30 to 85 Shore A — the full range certified HL3
Series 16 covers the full hardness range from 30 to 85 Shore A, all certified EN 45545-2 up to HL3. This allows a single material to be specified for all silicone gaskets and parts on the vehicle, simplifying the management of type approvals and fire documentation.
Soft — 30 to 35 Shore A
30 · 35 Shore AVery flexible fire-retardant silicone. Tensile 5–6 MPa, elongation 550–850%, tear 17–25 kN/m. The 30 ShA hardness achieves the highest tear strength of the entire range (25 kN/m). Ideal for seals requiring high deformability and resistance to tear propagation.
- Tensile (MPa min)
- 5–6
- Elongation (% min)
- 550–850
- Tear (kN/m min)
- 17–25
- Density (g/cm³)
- 1.09–1.18
Process: Extrusion and moulding. Sheet thicknesses 1–12 mm.
Medium — 50 to 60 Shore A
50 · 60 Shore AThe most versatile range. Tensile 8–9 MPa, elongation 450–480%, tear 18–20 kN/m. Optimum balance between flexibility and mechanical resistance. 60 ShA is the standard for flat flange gaskets and equipment seals.
- Tensile (MPa min)
- 8–9
- Elongation (% min)
- 450–480
- Tear (kN/m min)
- 18–20
- Density (g/cm³)
- 1.14–1.26
Process: Extrusion and moulding. Sheet thicknesses 0.5–12 mm. 60 ShA in stock.
Hard — 70 to 85 Shore A
70 · 85 Shore ARigid fire-retardant silicone. Tensile 9 MPa (70 ShA), elongation 380%. High resistance to compression and deformation under load. For parts working under permanent mechanical stress or requiring dimensional stability under pressure.
- Tensile (MPa min)
- 9
- Elongation (% min)
- 380
- Tear (kN/m min)
- 20
- Density (g/cm³)
- 1.18–1.26
Process: Extrusion and moulding. Sheet thicknesses 0.5–10 mm.
All hardnesses from 30 to 85 Shore A are certified EN 45545-2 R22/R23 up to HL3. Sheet thicknesses: 0.5 to 12 mm. Standard roll width 1,000 mm. Tolerances ISO 3302 M2 (moulding) and E1 (extrusion).
EN 45545-2: actual laboratory data
Series 16 — Extrusion (PEQ1630 → PEQ1685)
Fire-retardant solid silicone, peroxide-cured, processable by extrusion. Hardnesses 30 to 85 Shore A. Tested at 3 mm thickness. Results well below the regulatory limits on all parameters, achieving HL3 with margin. Available colours: black (RAL 9017), blue-black (RAL 5004).
Extruded profiles, cords, tubes, calendered sheet. Rolling stock, metro, tram, buses.
| Test | Standard | Series 16 result | HL3 limit |
|---|---|---|---|
| Oxygen index (%) | EN ISO 4589-2 | 32.7 | ≥ 26 |
| Ds max (optical smoke density) | EN ISO 5659-2 (25 kW/m²) | 84.7 | ≤ 300 |
| ITCPNL (toxicity) | EN 17084 (600 °C) | 0.06 | ≤ 1.2 |
| Levels achieved | — | HL1, HL2, HL3 | — |
Testing conducted in an accredited external laboratory. Tested thickness: 3 ±0.15 mm. Requirement sets R22 and R23. Results are valid for formulations PEQ1630 to PEQ1685 (hardnesses 30 to 85 ShA).
Series 16 — Moulding (PMQ1630 → PMQ1685)
Fire-retardant solid silicone, peroxide-cured, processable by moulding (compression or injection). Hardnesses 30 to 85 Shore A. Tested at 3 mm thickness. Moulding results are better than extrusion: oxygen index 35.1% (vs. 32.7%) and Ds max 45 (vs. 84.7%). Available colours: black (RAL 9017), grey, cream.
Moulded parts: O-rings, seals, mounts, dampers, technical parts to drawing.
| Test | Standard | Series 16 result | HL3 limit |
|---|---|---|---|
| Oxygen index (%) | EN ISO 4589-2 | 35.1 | ≥ 26 |
| Ds max (optical smoke density) | EN ISO 5659-2 (25 kW/m²) | 45 | ≤ 300 |
| ITCPNL (toxicity) | EN 17084 (600 °C) | 0.06 | ≤ 1.2 |
| Levels achieved | — | HL1, HL2, HL3 | — |
Testing conducted in an accredited external laboratory. Tested thickness: 3 ±0.15 mm. Requirement sets R22 and R23. Results are valid for formulations PMQ1630 to PMQ1685 (hardnesses 30 to 85 ShA).
Mechanical properties — Full Series 16
Series 16 maintains mechanical properties comparable to those of a high-quality standard silicone, despite incorporating flame-retardant additives. The formulation has been optimised so that the additive does not significantly degrade tensile strength, elongation or tear resistance.
Mechanical property reference for gasket and part design.
| Hardness (Shore A) | Tensile (MPa min) | Elongation (% min) | Tear (kN/m min) | Density (g/cm³) |
|---|---|---|---|---|
| 30 | 5 | 850 | 25 | 1.09–1.17 |
| 35 | 6 | 550 | 17 | 1.10–1.18 |
| 50 | 8 | 480 | 18 | 1.14–1.23 |
| 60 | 9 | 450 | 20 | 1.18–1.26 |
| 70 | 9 | 380 | 20 | 1.18–1.26 |
Data: Series 16 Progress Silicones. Standards: hardness ISO 7619-1, tensile/elongation ISO 37, tear ISO 34-1, density ISO 2781. Temperature range –60 °C to +200 °C. Hardnesses up to 85 ShA available to order.
Fire-retardant solid silicone, peroxide-cured, processable by extrusion. Hardnesses 30 to 85 Shore A. Tested at 3 mm thickness. Results well below the regulatory limits on all parameters, achieving HL3 with margin. Available colours: black (RAL 9017), blue-black (RAL 5004).
Extruded profiles, cords, tubes, calendered sheet. Rolling stock, metro, tram, buses.
| Test | Standard | Series 16 result | HL3 limit |
|---|---|---|---|
| Oxygen index (%) | EN ISO 4589-2 | 32.7 | ≥ 26 |
| Ds max (optical smoke density) | EN ISO 5659-2 (25 kW/m²) | 84.7 | ≤ 300 |
| ITCPNL (toxicity) | EN 17084 (600 °C) | 0.06 | ≤ 1.2 |
| Levels achieved | — | HL1, HL2, HL3 | — |
Testing conducted in an accredited external laboratory. Tested thickness: 3 ±0.15 mm. Requirement sets R22 and R23. Results are valid for formulations PEQ1630 to PEQ1685 (hardnesses 30 to 85 ShA).
Fire-retardant solid silicone, peroxide-cured, processable by moulding (compression or injection). Hardnesses 30 to 85 Shore A. Tested at 3 mm thickness. Moulding results are better than extrusion: oxygen index 35.1% (vs. 32.7%) and Ds max 45 (vs. 84.7%). Available colours: black (RAL 9017), grey, cream.
Moulded parts: O-rings, seals, mounts, dampers, technical parts to drawing.
| Test | Standard | Series 16 result | HL3 limit |
|---|---|---|---|
| Oxygen index (%) | EN ISO 4589-2 | 35.1 | ≥ 26 |
| Ds max (optical smoke density) | EN ISO 5659-2 (25 kW/m²) | 45 | ≤ 300 |
| ITCPNL (toxicity) | EN 17084 (600 °C) | 0.06 | ≤ 1.2 |
| Levels achieved | — | HL1, HL2, HL3 | — |
Testing conducted in an accredited external laboratory. Tested thickness: 3 ±0.15 mm. Requirement sets R22 and R23. Results are valid for formulations PMQ1630 to PMQ1685 (hardnesses 30 to 85 ShA).
Series 16 maintains mechanical properties comparable to those of a high-quality standard silicone, despite incorporating flame-retardant additives. The formulation has been optimised so that the additive does not significantly degrade tensile strength, elongation or tear resistance.
Mechanical property reference for gasket and part design.
| Hardness (Shore A) | Tensile (MPa min) | Elongation (% min) | Tear (kN/m min) | Density (g/cm³) |
|---|---|---|---|---|
| 30 | 5 | 850 | 25 | 1.09–1.17 |
| 35 | 6 | 550 | 17 | 1.10–1.18 |
| 50 | 8 | 480 | 18 | 1.14–1.23 |
| 60 | 9 | 450 | 20 | 1.18–1.26 |
| 70 | 9 | 380 | 20 | 1.18–1.26 |
Data: Series 16 Progress Silicones. Standards: hardness ISO 7619-1, tensile/elongation ISO 37, tear ISO 34-1, density ISO 2781. Temperature range –60 °C to +200 °C. Hardnesses up to 85 ShA available to order.
From the certified compound to your type-approved part
The process is adapted to the format: sheet for cutting/die-cutting, extrusion for profiles and cords, moulding for complex-geometry parts. In all cases, the compound is Series 16 with the same EN 45545-2 certification.
Application sectors
Rail
Gaskets, seals and profiles certified EN 45545-2 HL3 for trains, metros and trams.
Aerospace
Low-smoke fire-retardant seals for cabin interiors and on-board equipment.
Nuclear
Self-extinguishing gaskets for seals in nuclear installations with fire requirements.
Electronics
UL 94 fire-retardant seals for enclosures, electrical cabinets and signalling equipment.
Related products
Sponge Silicone Sheet
Includes fire-retardant grade Series 33 (cellular EN 45545-2 HL1/HL2) for compressible seals.
Food-Grade Silicone Sheet
Solid FDA sheet for gaskets in applications without fire requirements.
Conductive Silicone Sheet
Carbon-loaded sheet for ESD protection in ATEX applications.
TIXAN'AIR® Inflatable Seals
Pneumatic seals — available in fire-retardant silicone on request.
Need certified fire-retardant silicone for your railway project?
Tell us the required hazard level (HL1, HL2 or HL3), the fire requirements (R22, R23 or others), the format (sheet, profile, moulded part), the dimensions and the quantity. We provide a quotation with the complete fire documentation for your type-approval file.
Request quotation