Carbon Accounting for Packaging Buyers: A 5-Step Framework

Scope 3 is no longer optional

If your brand has investor reporting, retailer scorecards, or B Corp certification on the roadmap, Scope 3 carbon accounting for packaging is now a required line item — not a marketing exercise.

The 5-step framework

1. Inventory every material

List every material by SKU: foam, corrugate, paper, plastic film, ink, labels. Weights in grams per unit.

2. Apply emission factors

Use the EPA WARM model or the DEFRA conversion factor database:

• EPS foam: 3.4 kg CO₂e/kg
• Molded pulp: 1.1 kg CO₂e/kg
• Mycelium: 0.4 kg CO₂e/kg (Cerda LCA, 2025)

3. Multiply by annual volume

Units × grams × emission factor = annual kg CO₂e per material.

4. Identify your top 3 offenders

For most SMB brands, EPS foam is the #1 source of packaging carbon despite being a small fraction of total weight.

5. Model substitution

Recalculate with mycelium replacing foam. Typical brands see 60–85% packaging carbon reduction.

Sharing the number

Cerda provides per-order carbon reduction reports signed by an independent LCA reviewer — usable in CDP, GRI, and SBTi reporting. Request a sample and we'll model your top SKU at no charge.