Flame Retardant Systems

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

Aluminum hydroxide (ATH) is the highest-volume flame retardant by tonnage because it isninexpensive and halogen-free, but it decomposes near 200 C and needs high loadings, oftenn40 to 60% by weight, which lowers mechanical properties and raises melt viscosity. That isnthe central trade-off: clean, low-cost flame retardancy at the price of high filler loadnand harder processing. Use ATH where its decomposition temperature suits the polymer;nswitch to ammonium polyphosphate for higher-temperature or intumescent systems.

Antimony trioxide is a synergist, not a standalone retardant; it boosts halogenatednsystems at low loading and does little on its own. It carries a harmonized CLPnclassification as a suspected carcinogen (Carc. 2, H351) and is listed by IARC in Groupn2B, so confirm regulatory status for your application and jurisdiction before specifyingnit. Where a halogen-free profile is required, ammonium polyphosphate and ATH cover mostnintumescent and mineral-filled needs.

• 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

• Aluminum hydroxide (ATH) u2014 PubChem
• Ammonium polyphosphate (APP) u2014 PubChem
• Antimony trioxide (GHS/CLP hazard data) u2014 PubChem