ISO 22095-2:2026 gives polymer buyers a clearer way to test mass balance claims. The practical job is to connect every claimed characteristic to the correct site, system boundary, accounting method, transaction record, and customer-facing wording.
Direct answer for polymer buyers
ISO 22095-2:2026 is the first international standard dedicated to applying the mass balance chain-of-custody model. It covers system boundaries, input and credit accounting, conversion factors, double-counting controls, and claim communication. For buyers, the key task is linking each claimed characteristic to auditable site and transaction evidence.
Why the 2026 mass balance standard matters
Published in January 2026, the 45-page standard gives organizations a common framework for material or product flows where inputs with and without specified characteristics may be mixed or co-processed. It addresses the practical choices that often create confusion in polymer purchasing: geographical and time boundaries, rolling-average and credit methods, conversion factors, attribution, business-to-business communication, and public claims.
The standard does not turn a general sustainability statement into proof. A buyer still needs to identify the certification or assurance scheme, the certified legal entity and site, the characteristic being transferred, the accounting period, and the document that connects the purchased quantity to the claim. Technical product approval also remains separate from chain-of-custody accounting.
Definition: mass balance chain of custody
A mass balance chain of custody allows inputs with and without specified characteristics to be mixed or co-processed within a defined system while the eligible quantity and characteristics are recorded and attributed to outputs. The accounting must stay within the declared system boundary and prevent the same characteristic from being counted more than once.
| Model | Physical relationship | Buyer question |
|---|---|---|
| Controlled blending | Inputs are physically mixed under a model that controls the proportion of the specified characteristic. | What proportion is expected in the physical output, and how is it verified? |
| Mass balance | Eligible characteristics are accounted for and attributed across outputs inside a defined system; the exact molecules in a shipment are not the core proof. | What boundary, period, method, and transaction record support this attributed quantity? |
| Book and claim | The claim entitlement can be transferred separately from the physical material flow. | Is this claim detached from the purchased material, and is that clear in the wording? |
Mass balance chain-of-custody buyer checklist
How to read the supplier document set
| Document | What it can support | What it does not replace |
|---|---|---|
| Site or scheme certificate | The organization or site was audited for a stated scope and validity period. | Transaction-level proof that your order received an eligible attributed quantity. |
| Sustainability declaration | The specified characteristic, quantity, chain-of-custody route, and transfer between certified parties under the named scheme. | A technical data sheet, certificate of analysis, or application-performance approval. |
| TDS and COA | Grade identity, typical properties, lot results, and technical screening information. | Chain-of-custody entitlement, mass balance accounting, or public environmental-claim approval. |
Under the current ISCC PLUS description, physical segregation, controlled blending, and mass balance are available chain-of-custody options. It also states that each site handling alternative materials must hold a valid certificate, issued per site and valid for 12 months. These are scheme-specific rules, so buyers should always read the certificate and programme documents rather than importing them into another scheme.
Does mass balance prove physical content in one polymer shipment?
Not necessarily. The model is designed for systems where eligible and conventional inputs can be mixed or co-processed and where the eligible characteristic is transparently accounted for and attributed to outputs. A buyer should therefore distinguish an attributed mass balance claim from a measured physical-content statement.
This distinction matters in specifications. If a finished product needs a measurable recycled or bio-based content, name the analytical or calculation method and acceptance criterion separately. If the commercial target is an attributed mass balance characteristic, name the chain-of-custody method, scheme, documentary evidence, and approved wording.
2026 EU claims context for downstream customers
Mass balance documentation also needs to survive the next communication step. A July 2026 European Commission Transition Pathways update notes that Directive (EU) 2024/825 applies from 27 September 2026 and tightens rules against misleading environmental claims made to consumers. The update is consumer-law context, not a polymer certification rule.
For B2B buyers, the practical response is to keep a controlled claim sheet: the exact characteristic, chain-of-custody model, scope, evidence owner, approved sentence, prohibited shorthand, and destination market. ISO 22095-2 can improve consistency, but it should not be described as a legal safe harbour or as proof that every possible downstream claim is compliant.
Applying the checklist to SIS, SBS, and TPE/TPR discussions
Mass balance evidence and polymer performance should travel in the same qualification file but answer different questions. Chain-of-custody records support a specified sourcing characteristic. Grade selection still depends on the application, formulation route, melt or solution processing, viscosity, strength, hardness, ageing, compatibility, and customer test conditions.
When discussing a Jusage material, send the target application, grade or property direction, destination market, proposed environmental wording, required chain-of-custody model, and document list. Review the SIS Series and SBS Series for technical grade direction, then confirm any sustainability evidence and claim wording for the specific transaction instead of assuming that a product family page establishes it.
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Related Jusage pages
Connect chain-of-custody review with grade screening, application context, data-sheet requests, and a transaction-specific inquiry.