Overview
EN ISO 22526-2:2021 (identical to ISO 22526-2:2020) specifies a method 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 partly or wholly based on biobased constituents and provides a clear, repeatable approach for reporting the mass of atmospheric carbon sequestered in plastics.
Key topics and technical requirements
- Definition: Material carbon footprint = mass of CO2 removed from the air and incorporated into plastic.
- Scope: Applies to biobased synthetic polymers, natural polymers, additives and finished/semi‑finished plastic products.
- Measurement basis:
- Biobased carbon content must be determined by radiocarbon analysis as described in ISO 16620-2:2019 (sections 8.3.1–8.3.3) and may be expressed relative to total carbon (TC) or total organic carbon (TOC).
- The fraction of carbon in the product (m_c) is obtained by elemental analysis or from structural formulation.
- Calculation formulas:
- Convert biobased carbon (kg per kg polymer) to CO2 mass using the stoichiometric factor 44/12:
M_CO2 = (44 / 12) × M_B (where M_B is biobased carbon on a mass basis per 1 kg polymer).
- If biobased synthetic polymer content (m_BSP) is known, use M_CO2 = M_CO2,x × m_BSP (see Annex A for per‑polymer values).
- Limits on claims: The standard explicitly warns that material carbon footprint covers a single impact category and must not be used alone to claim overall environmental superiority.
Practical applications and users
Who uses EN ISO 22526-2:2021:
- Plastic manufacturers and polymer resin producers calculating biobased carbon sequestration.
- Sustainability and product stewardship teams preparing environmental product declarations (EPDs) or biobased content claims.
- LCA practitioners and consultants integrating biogenic carbon accounting into assessments.
- Certification bodies, procurement managers and regulators assessing biobased product claims.
Typical uses:
- Quantifying the mass of atmospheric CO2 incorporated in biobased plastics for labelling and procurement.
- Comparing feedstock choices (biobased vs fossil) in product design and supply‑chain reporting.
- Supporting targeted communications on carbon sequestration potential of biobased polymers.
Related standards
- ISO 16620 series (Parts 1–5) - Biobased content measurement and declaration methods.
- ISO 472 - Plastics vocabulary.
- ISO 16620-2:2019 - radiocarbon analysis for biobased carbon content.
Keywords: EN ISO 22526-2:2021, ISO 22526-2:2020, material carbon footprint, biobased plastics, biobased carbon content, CO2 removed from the air, biogenic carbon accounting.
