How to Calculate Recycled Content in Plastic Packaging (While the Details Are Still Evolving)

The problem: what companies are struggling with right now

• Unsettled “how to count” rules. Teams are building systems ahead of final calculation and verification guidance, especially around how mass balance should be applied and communicated.
• Mass balance = debate + claim risk. It’s useful for scaling certain recycling routes, but claim wording needs tight controls to avoid over-attribution.
• PCR supply and quality constraints. Food-contact and healthcare lines face tighter availability; variability in odor, color, and contaminants can affect performance and brand appearance.
• Traceability and audit readiness. Companies need defensible chain-of-custody evidence (segregated, controlled blending, or mass balance), consistent documentation, and credible third-party checks.
• Design complexity. Multi-material structures complicate both recyclability and recycled-content declarations; industry guidance continues to nudge toward simpler, mono-material designs.

A practical, claims-safe methodology you can use now (for any plastic type)

Goal: Create a repeatable, auditable way to calculate post-consumer recycled (PCR) content for each packaging type and format, aggregated as a plant-year average that stands up to audit.

1) Define the scope and data model

• Group by packaging “type” (predominant polymer) and “format” (size/shape). Keep rigid and flexible formats separate where they change BOMs or part weights.
• Separate contact-sensitive vs. non-contact-sensitive lines. Different specs and supply chains make reporting cleaner.
• Map every plastic part (bottle, film, label, cap, liner, fitments). Record unit-level part weights for each.

2) Establish traceability and what “counts”

• Count only post-consumer recycled (PCR) inputs toward your %; track pre-consumer separately to avoid claim errors.
• Capture evidence for each supplier batch: grade, feedstock origin, recycling route (mechanical/chemical), and chain-of-custody confirmation (e.g., ISCC PLUS, RecyClass) where applicable.
• If you use mass balance, align your internal method and claims language to your chosen scheme’s rules (e.g., attribution wording vs. “contains”).

3) Do the math (transparent and auditable)

1. At unit level:
   %PCR_unit = [ Σ (part weight × %PCR_part) / Σ (part weight) ] × 100
2. Aggregate to plant-year average for that type/format: weight units by quantity placed on the market to avoid bias from small runs.
3. Document exclusions and de minimis choices (e.g., tiny components you elect not to track) and keep your rulebook stable year over year.

4) Build an audit trail that survives scrutiny

• System of record: Link POs, delivery notes, supplier declarations, and certificates to production lots and finished SKUs.
• Internal controls: Periodic mass-balance checks at plant level (inputs vs. attributed outputs), quarterly variance reviews, and sample testing where feasible.
• Third-party review: Consider certification (RecyClass, ISCC PLUS) for added trust; both emphasize traceability and disciplined calculation.

5) Make the methodology “living,” not static

• Supplier development: Pre-qualify PCR suppliers for quality and compliance; track defect and claim rates.
• Design choices: Use DfR guidance to rationalize structures and improve both recyclability and recycled-content feasibility.
• Scenario planning: Model plant-year outcomes under different supply mixes (e.g., more mechanical vs. chemical PCR) and claim constraints.

Worked micro-example (illustrative)

Type/format: Rigid HDPE bottle, 250 ml (Plant A, CY2026)

• Avg. bottle: 20 g at 35% PCR → 7.0 g PCR
• Cap: 2 g at 0% PCR → 0.0 g PCR
• Label: 1 g at 80% PCR → 0.8 g PCR
• Numerator: 7.0 + 0.0 + 0.8 = 7.8 g PCR
• Denominator: 20 + 2 + 1 = 23 g
• Unit-level %PCR: 7.8 / 23 = 0.3391 → 33.9%
• Plant-year average: Weight by units produced/placed for each run; report the final plant-year % for this type/format with your supporting evidence bundle.

FAQs

What if we can’t source enough food-contact PCR?

Use dual-sourcing playbooks (mechanical + chemical PCR), qualify alternates early, and keep claims aligned with certification wording. Expect tighter supply and higher QA burden for contact-sensitive lines.

Is mass balance “allowed”?

It’s widely used as a chain-of-custody method. Policy treatment and claim rules are still being refined, so align your internal rules to the scheme you certify against and use approved wording.

How do we avoid greenwashing claims?

Keep documentation-to-claim symmetry: if attribution is used, say so; avoid implying physical PCR beyond what your chain-of-custody supports; and use third-party certification for higher trust.