- ▸ Halogen-free intumescent flame retardant in intumescent coatings and fire-protective paints, where it expands on heating to form an insulating char that protects steel and substrates.
- ▸ Flame-retardant additive compounded into flexible and rigid polyurethane foams, EPS/XPS insulation boards, and thermoplastics to raise fire ratings without halogenated chemistry.
- ▸ Active component in fire-stopping seals, pipe collars, intumescent strips, and fire-resistant gaskets that swell to seal openings during a fire.
- ▸ Filler for conductive and thermally-conductive composites, gasket sheet, and friction materials in industrial manufacturing.
- ▸ Feedstock for producing expanded/exfoliated graphite and flexible graphite foil used in high-temperature sealing applications.
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
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Expandable graphite is a halogen-free intumescent flame retardant — acid-intercalated graphite that expands dramatically when heated, forming a thick, insulating char layer (a graphitic “worm”) that shields the substrate. Identity: CAS 7782-42-5.
What it is
Expandable graphite (CAS 7782-42-5, carbon) is intercalated flake graphite: an acid is inserted between the graphite layers. It is halogen-free and is characterized by its expansion volume, onset temperature and flake size.
How it performs in fire
On heating past its onset temperature, the intercalant gasifies and forces the graphite layers apart, expanding the flake up to a hundredfold or more into a low-density, insulating carbon char that blocks heat and oxygen. This physical intumescence makes it highly effective, especially in polyurethane foam, seals and intumescent coatings, and it synergizes with phosphorus systems.
Applications
Expandable graphite is used in rigid and flexible polyurethane foam, intumescent fire seals and strips, coatings, and halogen-free polyolefin and EVA compounds, often with APP. See intumescent systems in the flame retardants guide.
Forms, grades and handling
Expandable graphite is supplied as a flake powder graded by expansion volume, onset temperature and mesh size, in bags and bulk. Properties are typical reference values; the Certificate of Analysis (CoA) for the lot you buy governs. Handle per the current Safety Data Sheet (SDS), and confirm regulatory status and restrictions for your market and end use. Each lot ships with CoA, TDS and SDS.
Bulk supply and RFQ
RawSource sources Expandable Graphite direct from producers in bulk, with CoA, TDS and SDS per lot. Tell us your polymer or system, the fire test you must pass, your maximum loading, and any particle-size or grade requirement, and we will quote the right grade. See the full range and selection logic in the flame retardants guide.
Typical Properties
Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.
| Property | Typical Value |
|---|---|
| Chemical / class | Flame retardant (intumescent graphite) |
| Flame-retardant type | Intumescent (physical expansion) |
| Role in fire performance | Expands into insulating char layer |
| CAS Number | 7782-42-5 |
| Molecular Formula | C |
| Handling | Refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 231-955-3
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Frequently Asked Questions
What is expandable graphite used for?
Expandable graphite (CAS 7782-42-5) is a halogen-free intumescent flame retardant for polyurethane foam, intumescent fire seals and coatings, and halogen-free polyolefin/EVA compounds. On heating it expands up to a hundredfold into an insulating carbon char that shields the substrate.
How does expandable graphite work?
It is acid-intercalated graphite; when heated past its onset temperature the intercalant gasifies and forces the graphite layers apart, expanding the flake into a low-density insulating char (a graphitic ‘worm’) that blocks heat and oxygen.
How is bulk expandable graphite supplied and quoted?
RawSource supplies expandable graphite in bulk with CoA, TDS and SDS per lot. Pricing is quote-based on grade, particle size and volume; submit an RFQ with your polymer/system and the fire test you must pass.
What is the REACH and TSCA regulatory status of Expandable Graphite?
Expandable Graphite (CAS 7782-42-5) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 231-955-3).