Plastics — Polystyrene
Materials High Confidence
Carbon Cost Index Score
3 kgCO₂e / per kg
Per kg
3 kgCO₂e / kg
Methodology v1.0 · Last reviewed 2026-04-08
Scope Breakdown
| Scope | kgCO₂e | % of Total | Distribution |
|---|---|---|---|
| Scope 1 | 0.4 | 13% | |
| Scope 2 | 0.3 | 10% | |
| Scope 3 | 2.3 | 77% | |
| Total | 3 | 100% |
Emission Hotspots
| Emission Hotspot | Scope | Est. % of Total |
|---|---|---|
| Styrene monomer production (ethylbenzene dehydrogenation) | S3 | 50% |
| Benzene and ethylene feedstock production | S3 | 18% |
| PS polymerization (suspension or bulk process) | S2 | 13% |
| Pelletizing and compounding | S1 | 10% |
| Transport and logistics | S3 | 9% |
Manufacturing Geography
- Region
- China, USA, EU, Japan, South Korea
- Grid Intensity
- 565 gCO2e/kWh (IEA 2024, China)
Material Composition Assumptions
The default reference product is 1 kg of general-purpose polystyrene (GPPS) resin granulate:
- Styrene monomer: ~99% of resin mass. Produced by dehydrogenation of ethylbenzene, which in turn is produced by alkylation of benzene with ethylene. Styrene production is a multi-step petrochemical process.
- Initiator: Organic peroxide or thermal initiation for free-radical polymerization.
- Additives: Antioxidants, mold release agents, colorants. <1% by weight.
Polystyrene exists in three main commercial forms: GPPS (transparent, rigid), HIPS (rubber-modified, impact-resistant), and EPS (expanded, foamed). This score covers solid GPPS/HIPS resin. EPS has additional expansion-stage emissions covered in the shipping-packaging-foam category.
Manufacturing Geography
PS production is concentrated in major petrochemical hubs:
- China: Largest producer and consumer.
- USA: INEOS, AmSty, Total. Gulf Coast production.
- EU: INEOS, Total, Trinseo.
- Japan/South Korea: PS Japan, LG Chem.
Regional Variation
| Production Region | Estimated Score (per kg) | Adjustment |
|---|---|---|
| Global average (default) | 3.0 kgCO2e | Baseline |
| USA | 2.5 kgCO2e | -17% |
| EU | 2.7 kgCO2e | -10% |
| China | 3.3 kgCO2e | +10% |
| Recycled PS | 1.0-1.5 kgCO2e | -55% |
Provenance Override Guidance
- EPD for the specific PS grade (GPPS, HIPS, or EPS pre-expansion).
- Recycled content: rPS from post-industrial or post-consumer waste.
- Supplier-level PCF data from resin producers.
Methodology Notes
- CCI score of 3 kgCO2e/kg is a conservative global average. PlasticsEurope reports 2.7-3.1 kgCO2e/kg for GPPS. The CCI score accounts for the global production mix including Chinese manufacturing.
- Scope breakdown: Scope 3 at 77% (2.3 kgCO2e/kg) from styrene monomer and benzene/ethylene feedstock. Scope 1 at 13% (0.4 kgCO2e/kg). Scope 2 at 10% (0.3 kgCO2e/kg).
- Confidence: High — well-documented resin with extensive PlasticsEurope eco-profile data.
- Functional unit: 1 kg of GPPS resin granulate, cradle to gate.
- PS vs. EPS: Solid PS (3 kgCO2e/kg) should not be confused with foamed EPS packaging (~3.5 kgCO2e/kg) which adds expansion and molding energy. See shipping-packaging-foam for EPS.
Related Concepts
Related Categories
Sources
- PlasticsEurope (2016) — Eco-profiles: General Purpose Polystyrene (GPPS) and High Impact Polystyrene (HIPS). Reports cradle-to-gate GWP of approximately 2.7-3.1 kgCO2e/kg for GPPS granulate.
- Franklin Associates (2011) — Life Cycle Inventory of Foam Polystyrene, Paper-Based, and PLA Food-Service Products. Provides cradle-to-gate data for polystyrene resin production.
- American Chemistry Council (2017) — Cradle-to-Gate LCI of Nine Plastic Resins. Reports GPPS at approximately 2.4 kgCO2e/kg for US production.
- IEA (2024) — Emissions Factors 2024. Grid intensities for major chemical production regions.
- GHG Protocol (2014) — Scope 3 Calculation Guidance. Emission factors for purchased plastic resins.