Overview
ISO 19984-2:2017 - "Rubber and rubber products - Determination of biobased content - Part 2: Biobased carbon content" specifies laboratory methods to measure the biobased carbon content of rubber and rubber products (including polyurethanes). The standard uses radiocarbon analysis (14C) to distinguish carbon originating from recent biomass versus fossil sources, enabling quantitative reporting of the fraction of carbon atoms in a product that are biobased. ISO 19984-2 is part of the ISO 19984 series and applies to raw materials, intermediate materials and final rubber products.
Key technical topics and requirements
- Scope and principle: Determines biobased carbon as the mass fraction of carbon derived from biomass relative to total carbon (χB = CB / (CB + CF + CNB) × 100).
- Radiocarbon (14C) approach: Uses the naturally occurring radiocarbon concentration (pMC or 14C activity) as a tracer - fossil carbon is essentially devoid of 14C.
- Two accepted measurement methods:
- Method A - Accelerator Mass Spectrometry (AMS): direct isotope-ratio measurement of 12C, 13C and 14C. Typical sample amount 1–10 mg; measurement time ~10–30 min; relative standard deviation ~0.2%–2.0%.
- Method B - Liquid Scintillation Counting (LSC): indirect 14C determination via beta decay counting. Sample amount range ~0.5 mg–2 g; measurement time ~4–24 h; relative standard deviation ~0.2%–10%.
- Sample preparation: Complete oxidation of sample carbon to CO2 prior to measurement (sample prep methods described in Annex A/B).
- Sampling references: Cross-references to ISO sampling standards (e.g., ISO 123, ISO 124, ISO 1795, ISO 15528, ISO 4661-2) for latex, raw materials and vulcanized rubber.
- Corrections and calibration: Applies correction factors for atmospheric 14C variations (notably the nuclear-bomb peak era) and uses standard reference materials (e.g., SRM 4990c) with a REF (100% biobased carbon) value in accordance with ASTM D6866.
- Documentation: Requirements for test reports, precision data and examples (Annexes C–E).
Practical applications and users
- Who uses it: Rubber manufacturers, compounders, environmental compliance teams, testing laboratories, certification bodies and R&D groups working on bio-based elastomers and sustainable materials.
- Practical uses:
- Verify biobased claims on rubber products and raw materials when formulation details are unavailable.
- Support eco-labeling, sustainability reporting and supply-chain verification.
- Compare measured biobased carbon content against theoretical formulation-based calculations (ISO 19984-1).
- Guide product development when substituting fossil-derived ingredients with biomass-derived alternatives.
Related standards
Keywords: ISO 19984-2:2017, biobased carbon content, rubber products, 14C, radiocarbon, AMS, LSC, biobased content determination, sustainability, ISO standard.
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