Food Packaging -- Plastics (PET, HDPE, PP)

Material Composition Assumptions

The default reference is 1 kg of virgin food-grade plastic packaging, modeled as a weighted blend of the three most common food-contact polymers:

• PET (polyethylene terephthalate): Bottles, clamshells, thermoformed trays — approximately 40% of food packaging plastic by mass. Virgin PET resin has a GWP of approximately 2.23 kgCO2e/kg at the resin pellet stage, rising to approximately 3.0-3.5 kgCO2e/kg after conversion (blow molding, thermoforming).
• HDPE (high-density polyethylene): Milk jugs, cereal box liners, rigid containers — approximately 30% of food packaging plastic. Virgin HDPE resin at approximately 1.8-2.6 kgCO2e/kg depending on system boundary.
• PP (polypropylene): Yogurt cups, microwaveable containers, bottle caps — approximately 30% of food packaging plastic. Virgin PP resin at approximately 1.6-2.0 kgCO2e/kg.

The blended CCI score of 3.4 kgCO2e/kg represents virgin resin through conversion into finished packaging (cradle-to-gate), including feedstock extraction, cracking, polymerization, and conversion processes (extrusion, molding, thermoforming). This value is conservative; cradle-to-resin-pellet values are lower (approximately 1.6-2.6 kgCO2e/kg) but exclude conversion energy.

All polymers are assumed to be 100% virgin. Inclusion of recycled content (post-consumer or post-industrial) would reduce the score, with recycled PET showing approximately 50-75% lower GWP than virgin PET.

Manufacturing Geography

The default manufacturing scenario assumes a global weighted average reflecting major production regions:

• Grid intensity (China): 565 gCO2e/kWh (IEA Emissions Factors 2024). China is the world’s largest producer of plastic packaging.
• Grid intensity (EU): ~300 gCO2e/kWh (average). Europe is a major producer with more moderate grid carbon intensity.
• Grid intensity (USA): ~390 gCO2e/kWh (EPA eGRID 2024).
• Rationale: Feedstock extraction and cracking (Scope 3) dominate the footprint at approximately 35%, and these emissions are relatively insensitive to grid mix since they are driven by petrochemical process energy (typically natural gas). However, the conversion step (extrusion, blow molding) is electricity-intensive, making grid carbon intensity relevant for Scope 2.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
Global weighted (default)	~450 gCO2e/kWh	3.4 kgCO2e/kg	Baseline
China	~565 gCO2e/kWh	3.7 kgCO2e/kg	+9%
EU (average)	~300 gCO2e/kWh	3.1 kgCO2e/kg	-9%
USA	~390 gCO2e/kWh	3.3 kgCO2e/kg	-3%
Middle East (gas-based feedstock)	~500 gCO2e/kWh	3.0 kgCO2e/kg	-12%

Note: The Middle East benefits from low-cost ethane feedstock (natural gas liquids), which has a lower cracking energy requirement than naphtha-based feedstock used in Europe and Asia. This reduces upstream Scope 3 emissions despite a moderate grid intensity.

Provenance Override Guidance

A supplier or brand may override the default CCI score by submitting:

1. Environmental Product Declaration (EPD) or Product Carbon Footprint (PCF) certified per ISO 14067 or the EU Product Environmental Footprint (PEF) method, with system boundary specified (cradle-to-resin vs. cradle-to-gate including conversion).
2. Resin sourcing data specifying polymer type, virgin vs. recycled content percentage, and feedstock origin (naphtha, ethane, or bio-based). Post-consumer recycled (PCR) PET at greater than 50% content can reduce the CCI score by 30-50%.
3. Conversion facility energy data specifying electricity consumption per kg of output, fuel mix for any thermal processes, and renewable energy procurement (PPAs or RECs).
4. Mass-balance or ISCC PLUS certification for bio-attributed or chemically recycled content, specifying the attribution methodology and chain-of-custody approach.
5. Transport mode and distance data for resin pellet supply and finished packaging distribution.

Methodology Notes

• CCI score of 3.4 kgCO2e/kg represents a conservative estimate for virgin food-grade plastic packaging through conversion. Literature values for cradle-to-resin range from 1.6-2.6 kgCO2e/kg depending on polymer; conversion adds approximately 0.8-1.2 kgCO2e/kg for blow molding and thermoforming processes.
• Scope breakdown: Scope 3 dominates at 53% (1.8 kgCO2e/kg), driven by upstream feedstock extraction, naphtha cracking, and additive production. Scope 2 (electricity for conversion machinery) is 26% (0.9 kgCO2e/kg). Scope 1 (direct process emissions from polymerization, on-site combustion) is 21% (0.7 kgCO2e/kg).
• Functional unit: 1 kg of finished food-grade plastic packaging, cradle-to-gate. The gate is the finished packaging item ready for filling.
• Use-phase and end-of-life emissions are excluded. Incineration of 1 kg of plastic packaging releases approximately 2.0-3.1 kgCO2e depending on polymer carbon content. Landfill emissions are minimal in the short term but represent foregone material value.
• Data gaps: Conversion energy varies widely by packaging format (thin film vs. rigid container vs. bottle). The estimate uses a moderate conversion energy assumption. Specific packaging formats would benefit from format-specific LCA data.