ISO’s official project page records 27 October 2026 as the start of voting on ISO/FDIS 21870. The final draft concerns determination of high-temperature loss on heating of carbon black by thermogravimetry for rubber compounding. It remains under development: this is a new approval-stage event, not publication of a new final International Standard.
What the carbon black test measures
The official scope describes volatile material beyond that released at 125°C and assessment of decomposing surface groups and adsorbed substances. This result should not be read as a particle-size, tinting-strength or dispersion measurement. A meaningful comparison needs the method, test conditions and sample identification as well as the reported number.
For a buyer, the useful response is to make the quality specification more precise. Ask for the test-method edition, test date and batch reference when reviewing a certificate of analysis. Confirm which properties are acceptance criteria for the intended formulation. A laboratory result for one property does not replace application testing in the finished compound.
Gohar Farayand supplies N330 industrial carbon black through its trading activity and produces P-30 black pigment. Rubber reinforcement and pigment selection involve different requirements. Before comparing prices, identify the relevant grade and request the available technical information. The ISO project does not imply certification of either product or require that different grades be interchangeable.
Analysis
The voting milestone highlights comparability of test reports. It does not establish a new universal obligation or a product approval. Buyers can specify the method clearly now and review the final edition when ISO publishes it.