Overview
EN ISO 3262-11:2024 / ISO 3262-11:2024 specifies requirements and test methods for products made from naturally occurring talc in lamellar form containing carbonates (for example dolomite and magnesite associations). This updated standard (superseding the 2000 edition) defines essential and conditional characteristics for talc extenders used in pigments and extenders applications, and prescribes how to test and report conformity.
Key topics and requirements
- Scope and grades: Defines two mineralogical grades (Grade A and Grade B) of natural talc/carbonate materials, illustrated by a ternary diagram.
- Essential requirements (Table 1):
- Talc content: Grade A 90–70% mass; Grade B 70–50% mass (determined by X-ray diffraction or agreement).
- Carbonate content: Grade A 10–30%; Grade B 10–50%.
- Total talc/chlorite content: maximum 90% mass.
- Loss on ignition: Grade A 9.5–19.0% mass; Grade B 11.0–28.6% mass (ISO 3262-1).
- Matter volatile at 105 °C: max 0.5% mass (ISO 787‑2).
- Matter soluble in water: max 0.2% mass (ISO 787‑3).
- pH of aqueous suspension: typically 8–10 (ISO 787‑9).
- Quartz content: max 0.5% mass (XRD).
- Asbestos requirement: no asbestos detectable using combination of XRD and electron microscopy (ISO 14966; SEM/EDX or TEM recommended for morphology and low detection limits).
- Conditional requirements (Table 2):
- Residue on 45 µm sieve (ISO 787‑7 / ISO 787‑18).
- Particle size distribution by laser diffraction (ISO 8130‑13).
- Matter soluble in hydrochloric acid, colour/lightness, resistivity of aqueous extract - to be agreed between parties.
- Test reporting: Reports must identify the product, reference the standard, present methods and results, note deviations or anomalies, and include test dates.
Applications
- Quality specification and acceptance testing for extenders used in:
- Paints and coatings
- Plastics and rubber compounds
- Paper, ceramics and sealants
- Chemical and construction formulations
- Ensures consistent material performance, regulatory compliance (e.g., asbestos detection), and clear procurement criteria for suppliers and buyers.
Who should use this standard
- Manufacturers and suppliers of natural talc extenders
- Quality control and testing laboratories
- Product engineers in paints, plastics and paper industries
- Procurement and compliance teams specifying raw material acceptance
Related standards
Keywords: ISO 3262-11, EN ISO 3262-11:2024, natural talc, talc containing carbonates, extenders, test methods, particle size distribution, asbestos testing, pigments and extenders.
