FAR 25.853 Silicone

FAR 25.853 silicones are specialty elastomeric materials engineered to meet the flammability, smoke, and toxicity requirements defined in Federal Aviation Regulation (FAR) 25.853, the standard that governs materials used in aircraft cabin interiors and certain structural or systems‑level components. For aerospace manufacturers, MRO providers, and suppliers of gaskets, seals, and insulation components, these silicones provide a reliable path to compliance while maintaining the mechanical and environmental performance expected from high‑grade silicone rubber.

Flame Retardant

At its core, FAR 25.853 establishes how materials must behave when exposed to flame. The regulation includes vertical burn tests, horizontal burn tests, and heat release and smoke density requirements depending on the component’s location and function. Silicones formulated for this standard incorporate flame‑retardant additives and carefully balanced polymer systems that allow them to self‑extinguish, resist flame propagation, and limit smoke generation. Unlike commodity silicones, which may burn or drip under sustained flame, FAR 25.853 silicones are engineered to maintain structural integrity long enough to support safe evacuation and prevent fire spread.

Inherent Thermal Stability

One of the advantages of silicone as a base polymer is its inherent thermal stability. Standard silicones already perform well at elevated temperatures, but FAR‑rated formulations extend this capability with enhanced flame resistance. These materials typically retain flexibility, compression set resistance, and sealing performance across a broad temperature range, often from –60°C to +200°C, depending on the compound. This makes them suitable for cabin components, ducting seals, lighting gaskets, access panel seals, and other areas where both environmental sealing and flame performance are required.

Low Toxicity and Low Smoke Characteristics

FAR 25.853 silicones are also valued for their low toxicity and low smoke characteristics. In an aircraft environment, smoke density and chemical byproducts can be as dangerous as flame itself. Formulators design these materials to minimize smoke evolution and avoid halogenated flame retardants that could release corrosive or harmful gases. This aligns with broader aerospace trends toward cleaner, safer material systems.

Processing Flexibility

Processing flexibility is another benefit. FAR‑rated silicones can be die‑cut into gaskets or fabricated into custom shapes. Fabric‑reinforced versions can increase dimensional stability or tear resistance. Adhesive‑backed materials support quick installation in cabin interiors or equipment housings.

Ask ElastaPro for FAR 25.853 Silicones

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