Overview
EN ISO 3262-2:2023 - Extenders for paints - Specifications and methods of test - Part 2: Baryte (natural barium sulfate) is a harmonized CEN/ISO standard that specifies composition requirements and test methods for natural barium sulfate used as an extender in paints and related coatings. Published in 2023 and endorsed by CEN, it replaces the 1998 edition and is part of the ISO 3262 series covering extenders.
Key Topics and Requirements
This standard defines essential and conditional requirements and the corresponding test procedures. Key technical points include:
- BaSO4 content (barium sulfate): Minimum mass fraction requirements - Grade A ≥ 90%, Grade B ≥ 80%. Two determination routes are allowed:
- Gravimetric (acid-insoluble barium calculated as BaSO4)
- X‑ray fluorescence (XRF) (added in the 2023 revision)
- Particle size / residue on 45 µm sieve: For Grade A, maximum 0.5% residue on a 45 µm sieve; other sieve/particle size limits can be agreed between parties.
- Matter volatile at 105 °C: Maximum 0.5% (ISO 787-2 reference).
- pH of aqueous suspension: 6 to 10 (ISO 787-9).
- Loss on ignition, matter soluble in water, resistivity of aqueous extract, colour, lightness and matter soluble in hydrochloric acid: Specified as conditional requirements to be agreed by supplier and purchaser or determined per referenced methods (ISO 3262-1, ISO 787 series).
- Sampling and test reporting: Sampling according to ISO 15528 and standard test reporting requirements are included.
- Analytical notes: Presence of strontium sulfate can affect gravimetric results; subtraction via ICP‑OES or alternative analysis is suggested.
Practical Applications and Users
EN ISO 3262-2:2023 is used for quality control, procurement, specification and regulatory compliance where baryte is supplied or used as a pigment/extender. Typical users:
- Paint, coatings and ink manufacturers specifying extender quality
- Mineral suppliers and baryte producers certifying product grades
- Testing and QC laboratories performing BaSO4 content, sieve residue, pH and related analyses
- Procurement and standards teams drafting material specifications and supplier contracts
Benefits include clear acceptance criteria for baryte/barium sulfate, harmonized test methods (gravimetric and XRF), and reduced disputes through agreed conditional properties.
Related Standards
Relevant referenced standards include: ISO 3262-1, ISO 787 series (Parts 2, 3, 7, 9, 14), ISO 15528 (sampling), ISO 12677 (XRF fused-bead method), ISO 3696 (water quality) and ISO 18451-1 (terminology). These form the test-method and terminology framework for implementing EN ISO 3262-2:2023.