Overview
EN ISO 3262-20:2021 - “Extenders - Specifications and methods of test - Part 20: Fumed silica (ISO 3262-20:2021)” is the CEN-adopted ISO standard that specifies requirements and corresponding methods of test for fumed silica used as an extender/filler. Published in 2021 (second edition), this document replaces EN ISO 3262-20:2000 and was prepared by ISO/TC 256 in collaboration with CEN/TC 298.
Key topics and technical requirements
The standard defines test procedures and reporting requirements for quality assessment of fumed silica. Main technical topics include:
- Sampling and preparation of test portions to ensure representative results.
- Determination of silica content (principle, reagents, apparatus, procedure, expression of results and precision).
- Spectrometric determination of impurity oxides such as aluminium oxide (Al2O3), titanium(IV) oxide (TiO2) and iron(III) oxide (Fe2O3), including calibration, preparation of standard solutions and calculation of oxide contents.
- Carbon content measurement (combustion/analysis procedures, calibration and precision).
- Chloride content determination and reporting.
- Total loss on ignition and other typical compositional checks required for fumed silica extenders.
- Test report format and essential information to be recorded.
The 2021 revision includes editorial and technical updates such as a retitled main heading, revised carbon content and organic surface entries, changes in recommended desiccants, added examples for suitable carbon steel, and updated normative references.
Practical applications and users
This standard is intended for organizations involved in production, testing and use of fumed silica as an extender or filler in coatings and related formulations. Typical users:
- Manufacturers and suppliers of fumed silica for quality control and specification compliance.
- Analytical and QC laboratories performing compositional and impurity analyses (spectrometry, combustion, chloride tests).
- Paint, coatings and pigment formulators specifying filler performance and purity.
- Procurement and regulatory teams needing standardized test criteria and conformance evidence.
Applying EN ISO 3262-20:2021 ensures consistent quality control, comparable test data across laboratories, and clear specification language in commercial supply chains for extenders and fillers.
Related standards