Expandable Polystyrene
Pentane-blown polystyrene beads that mould into rigid, closed-cell insulation and packaging foam — the material behind building insulation boards, EIFS systems and protective packaging worldwide.
Chelora Chemicals supplies EPS beads to moulders, insulation-board plants and packaging converters worldwide, with full documentation and consistent bead quality on every consignment.
Product identity
- CAS Number
- 9003-53-6
- Common name
- EPS beads
- Base monomer
- Styrene (C₈H₈)
- Blowing agent
- n-Pentane / iso-pentane
- Softening point
- ~100 °C
- Bead bulk density
- 600-650 kg/m³
- UN Number
- UN 2211*
- HS Code
- 3903 11
* UN 2211 (Polymeric beads, expandable, evolving flammable vapour) applies to unexpanded beads; confirm exact classification for your shipment size and destination with your regulatory affairs team.
What Expandable Polystyrene is used for
Expandable Polystyrene (EPS) is a white, free-flowing bead product made by suspension-polymerising styrene monomer in the presence of a pentane blowing agent, which becomes trapped inside each bead. The beads themselves are solid and unexpanded until processed by the moulder.
EPS's single largest use is as the raw material for rigid, closed-cell insulation and packaging foam: beads are pre-expanded with steam, matured, and then fused in a mould to form insulation boards, EIFS (exterior insulation finishing system) panels, geofoam fill, and void-form blocks for construction. Its second major use is protective and food packaging — moulded boxes, trays and cushioning inserts for appliances, electronics, produce and seafood. Smaller volumes go into civil engineering lightweight fill, display and craft products, and horticultural growing media.
Where it sits in the petrochemical value chain
- Styrene Monomer the feedstock EPS beads are polymerised from. See that page.
- Expandable Polystyrene (this product) the pentane-impregnated bead supplied to moulders.
- Moulded EPS Foam the finished insulation board, packaging or fill product made by the moulder from these beads.
Handling character
EPS beads carry a flammable pentane blowing agent that off-gasses gradually in storage. Full hazard detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | White, free-flowing beads |
| Pentane content | 5-7% by weight |
| Bead size range | 0.2-2.5 mm (grade-dependent) |
| Residual styrene monomer | Within producer specification |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | White solid beads (unexpanded) |
| Softening point | ~100 °C |
| Bulk density (unexpanded) | 600-650 kg/m³ |
| Moulded foam density | 10-30 kg/m³ (typical) |
| Water solubility | Insoluble |
| Flash point (pentane content) | < 0 °C (highly flammable) |
Physical constants compiled from public reference data for CAS 9003-53-6 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put these beads to work
The bead that moulds into the insulation and packaging foam the construction and logistics industries rely on.
Building & EIFS insulation
Moulded into rigid insulation boards for wall, roof and floor systems, and EIFS cladding.
- Insulation-grade specification
- Bulk & bag supply
- Technical desk review on request
Protective & food packaging
Moulded boxes, trays and cushioning inserts for appliances, electronics, produce and seafood.
- Packaging-grade specification
- Documented batch traceability
- Contract & spot supply
Civil engineering & geofoam fill
Lightweight fill blocks for road embankments, void forms and landscaping applications.
- Packs sized to customer volumes
- Full analytical documentation available
- Retained sample held against the lot
Cold-chain & thermal shipping
Moulded coolers and shipping boxes for pharmaceutical and perishable cold-chain logistics.
- Documented batch traceability
- Technical desk review on request
Display, craft & horticulture
Used in display models, craft products and lightweight growing-media blends.
- Research & process-scale quantities
- Full documentation supplied
Contract & scheduled supply
Moulding plants running continuous consumption are supported with scheduled bulk delivery.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Expandable Polystyrene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Pentane content and bead-size distribution are critical to moulding yield — that shapes how we manage this line.
We place your order with whichever qualified producer best matches your required grade, your price point and your delivery window, and confirm your jurisdiction's import requirements before booking.
We keep a second qualified source on this line, so a single-plant disruption never becomes your production problem.
- Pentane content and bead size confirmed before we quote. Consistency matters to downstream moulding yield.
- UN 2211 documentation managed end to end. Classification, labelling and carrier compliance confirmed before booking.
- Scheduled call-off scheduling. We hold contracted tonnage and release it against your consumption calendar.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
- Export machinery handled in-house. Classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Insulation-grade and packaging-grade both sourced. Matched precisely to your moulding process.
Packed the way your plant receives it
Bag or bulk bag — tell us your preferred format and we will quote and classify to it.
20-25 kg multi-wall bags
Vented multi-wall paper bags sized for smaller-volume orders and trial quantities.
~500-1,000 kg FIBC/jumbo bags
Ventilated bulk bags sized for mid-to-large volume moulder orders.
Full-container-load shipment
Palletised bag loads in standard or ventilated containers for continuous-consumption moulding plants.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.
Trial / sample quantities
Small packs dispatched for process trials before a commercial order is placed.
Contracted call-off supply
We hold contracted tonnage and release it against your consumption calendar.
Flammable vapour — handle accordingly
EPS beads carry a flammable pentane blowing agent that evolves gradually in storage, particularly from warm or freshly produced material. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H223Flammable aerosol/vapour from entrapped pentane.H319Causes serious eye irritation (dust).
Store ventilated, away from ignition sources. Pentane vapour can accumulate in enclosed storage; always read the SDS issued with your specific batch and store accordingly.
Storage
Store in a cool, dry, well-ventilated area away from ignition sources and direct sunlight. Rotate stock to avoid extended holding, since pentane content and moulding performance decline with storage time.
Handling
Use standard PPE (gloves, eye and dust protection) for bag handling and transfer. Provide adequate ventilation in silos and moulding areas to prevent pentane vapour accumulation; avoid static discharge sources.
Transport
Shipped as UN 2211 (Polymeric beads, expandable, evolving flammable vapour); exact classification depends on pentane content and packaging quantity. We confirm and document classification for your specific shipment and destination.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
Bead size, pentane content and density grade confirmed against your moulding process before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS and transport paperwork checked by our desk before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How EPS is made
EPS beads are produced industrially by the suspension polymerisation of styrene monomer in water, with a pentane blowing agent introduced either during or after polymerisation so it becomes trapped inside each bead. This is a long-established route in polymer chemistry, distinct from extruded polystyrene (XPS) foam.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Chemical family | Vinyl polymer (polystyrene) |
|---|---|
| Form supplied | Unexpanded pentane-impregnated beads |
| Processing route | Steam pre-expansion, maturation, mould fusion |
| Related compounds | Styrene Monomer (feedstock), Extruded Polystyrene (XPS, related foam product) |
Explore the wider polymer range
Expandable Polystyrene, answered
What is Expandable Polystyrene used for?
How does EPS turn into foam?
Is Expandable Polystyrene hazardous?
What grade do you supply?
What packing do you offer?
Do you manufacture this yourself?
- Need a related elastomer? See our EPDM Rubber and Nitrile Rubber pages.
Get a quote on Expandable Polystyrene today
Send us your required grade, pack size and delivery window. We will come back with a firm quote, lead time and full documentation.