Plastics & Polymers / Solution Family

Flame Retardant Systems

Polymer flame-retardant raw materials — aluminum hydroxide (ATH), ammonium polyphosphate, and antimony trioxide synergist — for UL 94 and LOI compliance across mineral-filled, intumescent, and halogenated systems.

Overview

Flame retardants are additives that raise a polymer's resistance to ignition and slow flame spread so a part can meet a fire-safety standard such as UL 94 or a target limiting oxygen index. They work by different mechanisms: mineral fillers that absorb heat and release water, synergists that strengthen a gas-phase halogen system, and intumescents that swell into an insulating char. A compliant system usually combines one mechanism with the right loading for the polymer.

Aluminum hydroxide (ATH) is the highest-volume flame retardant by tonnage because it is inexpensive and halogen-free, but it decomposes near 200 C and needs high loadings, often 40 to 60% by weight, which lowers mechanical properties and raises melt viscosity. That is the central trade-off: clean, low-cost flame retardancy at the price of high filler load and harder processing. Use ATH where its decomposition temperature suits the polymer; switch to ammonium polyphosphate for higher-temperature or intumescent systems.

Antimony trioxide is a synergist, not a standalone retardant; it boosts halogenated systems at low loading and does little on its own. It carries a harmonized CLP classification as a suspected carcinogen (Carc. 2, H351) and is listed by IARC in Group 2B, so confirm regulatory status for your application and jurisdiction before specifying it. Where a halogen-free profile is required, ammonium polyphosphate and ATH cover most intumescent and mineral-filled needs.

Where it's used
  • Mineral-filled, halogen-free flame retardancy for wire and cable compounds
  • Intumescent coatings and char-forming polyolefin systems
  • Synergist packages for halogenated flame-retardant formulations
  • UL 94 V-0/V-1 and limiting-oxygen-index targets in engineering plastics
  • Building, transit, and E&E parts with low-smoke or RoHS/REACH requirements
Frequently asked questions
What flame retardants does RawSource supply for plastics?
RawSource sources aluminum hydroxide (ATH), a halogen-free mineral filler that absorbs heat and releases water; ammonium polyphosphate (APP), a halogen-free intumescent that swells into an insulating char; and antimony trioxide, a synergist that boosts halogenated flame-retardant systems at low loading.
What is the difference between a flame retardant and a synergist?
A flame retardant acts on its own — ATH cools the polymer endothermically, APP forms a protective char. A synergist such as antimony trioxide does little alone; it only works alongside a halogen source, where it sharply improves the efficiency of the halogenated system at low addition levels.
Are there halogen-free flame retardant options?
Yes. Aluminum hydroxide (ATH) and ammonium polyphosphate (APP) are both halogen-free, which suits RoHS/REACH, low-smoke, and low-toxicity specifications increasingly required in building, transit, and electrical/electronic parts. Confirm the loading and decomposition temperature against your polymer and the target standard.
Does RawSource supply flame retardants in bulk?
Yes. RawSource sources ATH, APP, and antimony trioxide in bags, drums, supersacks, and bulk quantities with full documentation (CoA, TDS, SDS). Send your polymer, target standard (e.g. UL 94 V-0 or an LOI value), and any halogen-free requirement through the bulk RFQ for grade selection and pricing.
Disclaimer. Information on this page is provided for general reference and compiled from authoritative public sources (e.g. PubChem/ECHA). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot you purchase governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim. Always consult the current Safety Data Sheet (SDS) before handling, and confirm regulatory status, classification, and suitability for your application and jurisdiction.
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