ISO 22526-2:2020

Overview

ISO 22526-2:2020 specifies how to quantify the material carbon footprint of biobased plastics - defined as the amount (mass) of CO2 removed from the air and incorporated into the polymer molecule. The standard applies to plastic products, materials and polymer resins that are wholly or partly based on biobased constituents. It provides a reproducible determination method tied to measured biobased carbon content and gives calculation routes to express CO2 removal per kilogram of polymer.

Key topics and technical requirements

• Definition: Material carbon footprint = mass of CO2 removed from air and incorporated into plastic.
• Scope: Applicable to biobased polymers, plastic materials, semi‑finished and finished products, monomers and additives with biogenic origin.
• Measurement basis:
  • Biobased carbon content is determined by radiocarbon analysis as referenced to ISO 16620-2 (TOC or TC basis).
  • Elemental analysis or structural formulation is used to obtain the fraction of carbon present in the product.
• Calculation methods:
  • Convert biobased carbon content on a mass basis (kg biobased C per kg polymer) into CO2 removed using the molecular mass ratio: M_CO2 = (44/12) × M_B.
  • Alternatively, use biobased synthetic polymer content and polymer‑specific CO2 removal factors (see Annex A).
• Polymer examples (Annex A):
  • Polylactic acid (PLA): ~1.83 kg CO2 removed per kg PLA.
  • Biobased polyethylene (bio‑PE): ~3.14 kg CO2 removed per kg bio‑PE.
  • Bio‑PET: examples provided (bio‑MEG ≈ 1.42 kg CO2/kg; bio‑PET ≈ 0.46 kg CO2/kg).
• Limitation: The material carbon footprint addresses only one impact category and “shall not be used for a communication on overall environmental superiority.”

Applications and who uses it

• Manufacturers and formulators of biobased plastics calculating the CO2 removal embodied in products.
• LCA practitioners and sustainability teams integrating biobased carbon metrics into product environmental assessments.
• Product certification bodies and compliance officers verifying biobased carbon claims.
• R&D and procurement professionals comparing feedstock options (e.g., PLA vs. bio‑PE) on carbon incorporation terms.
• Marketing and regulatory teams preparing accurate, standards‑aligned product declarations (with caution about single‑metric claims).

Related standards

• ISO 16620 series (Parts 1–5) - determination and declaration of biobased content (including ISO 16620‑2 for radiocarbon analysis and ISO 16620‑3 for biobased synthetic polymer content).
• ISO 472 - plastics vocabulary (terms and definitions referenced).

Keywords: ISO 22526-2, material carbon footprint, biobased plastics, biobased carbon content, CO2 removed, radiocarbon analysis, PLA, bio‑PE, bio‑PET.