HL3 Fire Retardant Compounds & Profiles
EN 45545-2 HL3 compliant EPDM and silicone compounds, rubber gaskets and extruded profiles for railway, metro and mass transit rolling stock.
Gayatri Minerals, 359, GIDC, Porbandar: 360575, Gujarat
gayatriminerals.gm@gmail.com
+91 98259 19197 / +91 98794 54515
HL3 Compliant
EN 45545-2 Fire Retardant
India's trusted HL3 compliant EPDM / Silicone manufacturer — certified to the most stringent fire-protection standard for railway vehicles. Precision-compounded fire retardant profiles and compounds are engineered to protect lives across India's rail network and global transit infrastructure.
In mass transit and railway engineering, compromise is never an option. EN 45545-2 governs the fire protection behaviour of every material and component inside a railway vehicle. HL3 — Hazard Level 3 — is the most stringent tier, mandatory for trains operating in extended underground tunnels, sleeping cars, and high-capacity transit corridors where evacuation time is longest.
Why HL3 EN 45545-2 Compliance Matters
As a certified HL3 compliant EPDM / Silicone manufacturer, Gayatri Minerals supplies fire retardant compounds and extruded profiles that meet procurement requirements for Indian Railways, metro systems, and global rolling stock integrators.
Low Flame Spread
Strictly restricts fire propagation across the material surface, containing the source before it can cascade into a life-threatening blaze.
Low Smoke Density
Dramatically reduces smoke emission to keep evacuation corridors and emergency exits visible during critical seconds.
Minimal Gas Toxicity
Prevents the release of lethal halogenated and acid gases during combustion — critical in enclosed underground environments.
Highest Safety Tier
HL3 sits at the apex of the EN 45545-2 framework — the benchmark that safety-critical railway procurement now demands globally.
Technical Specifications & Performance Data
Our compounds are custom-formulated in EPDM, Silicone, and Neoprene, balancing mechanical durability with HL3 compliant fire retardant properties — every batch validated in-house against EN 45545-2 HL3 requirements.
| Property | Test Standard | Performance | Status |
|---|---|---|---|
| Oxygen Index (OI) | ISO 4589-2 | ≥ 32% (Exceeds HL3 limit) | PASS |
| Smoke Density (Ds max) | ISO 5659-2 | Compliant with critical tunnel limits | PASS |
| Toxicity Index (CITg) | NF X 70-100-1/-2 | Well below maximum allowable threshold | PASS |
| Hardness Range | Shore A | 50 to 85 (Fully customizable) | PASS |
| Temperature Resistance | Continuous Operation | Optimized for severe climate variations | PASS |
| Tensile Strength | ISO 37 | Meets full mechanical duty requirements | PASS |
| Halogen Content | EN 14582 | Halogen-free compound available | PASS |
Applications in Rail & Transit
Our railway fire retardant components and fire resistant profiles are engineered for interior, exterior, and structural applications across high-speed trains, metro systems, locomotives, and light-rail vehicles — fully certified to EN 45545-2 HL3.
Airtight, weatherproof, and fire-safe rubber gasket and sealing profiles for all rolling stock door and window systems.
Flexible, high-fatigue resistant connecting joints between railway coaches and metro cars.
Noise, vibration & harshness damping elements that absorb shock without compromising fire safety.
Protecting critical electrical conduits from fire spread across the entire train body.
Load-bearing fire-retardant pads meeting RDSO specifications for Indian Railways track infrastructure.
Bespoke HL3 fire retardant profiles and molded components machined to your exact tolerances.
Rubber Gasket Manufacturer & Supplier
A rubber gasket is the sealing element that sits between two mating surfaces and keeps air, water, dust and noise out of the joint. Gayatri Minerals manufactures fire retardant rubber gaskets in EPDM, silicone and neoprene — extruded sections, moulded gaskets and vulcanised endless rings — produced to customer drawings in hardness grades from 50 to 85 Shore A. Every rubber gasket made on our HL3 line is compounded to the same EN 45545-2 HL3 fire, smoke and toxicity requirements as the rest of our railway range, so the seal never becomes the weak point in a certified assembly.
Typical applications include railway and metro door and window rubber gaskets, gangway and bellow seals, panel and hatch gaskets, cable entry grommets, and general industrial rubber gasket requirements for enclosures, tanks, pipe flanges and electrical cabinets. Custom profiles, colours and hardness are available, and sample sections can be supplied against your drawing before bulk production. Contact our engineers for a rubber gasket quotation.
Partner With Railway Fire Retardant Experts
Request technical datasheets, test certificates, or a quote from our engineering team.
gayatriminerals.gm@gmail.comGayatri Minerals, 359, GIDC, Porbandar: 360575, Gujarat
+91 98259 19197 / +91 98794 54515What HL3 Compliance Actually Requires
EN 45545-2 is the European standard governing the fire behaviour of materials and components inside railway vehicles. It grades requirements by hazard level — HL1, HL2 and HL3 — according to how difficult evacuation would be if a fire broke out. HL3 is the most demanding tier, applied to vehicles operating in extended underground sections, sleeping cars and high-capacity transit corridors where passengers cannot leave quickly.
Meeting HL3 is not a single test. A compliant compound has to satisfy several requirement sets simultaneously, and it is common for a formulation to pass one and fail another:
- Flammability and flame spread — the material must resist ignition and must not propagate fire across its surface.
- Smoke density — measured optically, because in a tunnel evacuation, visibility determines whether people find the exits.
- Gas toxicity — the conventional index of toxicity (CIT) limits the lethal and incapacitating gases released during combustion.
- Heat release — how much energy the burning material contributes to the fire it is caught in.
Our compounds are formulated in EPDM, silicone and neoprene to hold all four simultaneously while still meeting the mechanical duty the component was specified for — hardness, tensile strength, compression set and temperature range. Balancing fire performance against mechanical performance is the actual engineering problem in flame retardant compounding, and it is why an HL3 compound cannot simply be a standard compound with additive stirred in.
Halogen-free flame retardant chemistry
Halogenated flame retardants are effective at modest loadings but generate dense, corrosive, toxic smoke — precisely what the smoke density and toxicity clauses of EN 45545-2 are written to prevent. Modern rail specifications therefore push toward halogen-free formulations built on hydrated mineral flame retardants such as alumina trihydrate (ATH) and magnesium dihydroxide (MDH), which absorb heat and release water vapour as they decompose.
Those systems have to be loaded very heavily, which is what makes halogen-free compounding difficult and expensive — and why the choice of supporting mineral filler matters so much to the economics. Halogen-free compound is available across our HL3 range.
Fire Retardant Compounds vs. Mineral Fillers
Gayatri Minerals operates in two related but distinct areas, and buyers occasionally conflate them. It is worth being precise about the difference.
This division supplies certified fire retardant products. The HL3 compounds and extruded profiles on this page are formulated, compounded and validated against EN 45545-2 HL3 — the fire performance is the product, and it is backed by the test data set out above.
Our mineral division supplies natural calcium carbonate as a filler. Whiting chalk powder from our Porbandar mines is an inert mineral filler. It is not a flame retardant and we never sell it as one. Compounders across India buy it as the bulk filler component of their own flame retardant rubber, plastic, PVC and cable formulations — where it dilutes the combustible polymer fraction, stays halogen-free and thermally stable, and makes a high-loading ATH or MDH system commercially workable. The fire performance in those compounds comes from the active flame retardant system, not from the calcium carbonate.
If you need a material with certified fire performance, this page is the right place. If you are formulating your own flame retardant compound and need a consistent, clean, halogen-free mineral filler to build it around, the mineral division is.