SIST EN ISO 3262-3:2023 PDF

Overview

EN ISO 3262-3:2023 - "Extenders - Specifications and methods of test - Part 3: Blanc fixe" is the CEN/ISO standard that specifies requirements and test methods for blanc fixe (precipitated barium sulfate, BaSO4). Published in 2023 and endorsed by CEN, this edition replaces EN ISO 3262-3:1998 and updates analytical methods used for quality control and specification of blanc fixe supplied for industrial use.

Key topics and technical requirements

• Definition: Blanc fixe is a synthetic, precipitated barium sulfate produced by a precipitation process (ISO 3262-3:2023, clause 3.1).
• Essential requirements (typical values from the standard):
  • BaSO4 content (minimum): 95% mass fraction - determined by either gravimetric or X-ray fluorescent (XRF) methods (Clauses 6 & 7).
  • Residue on 45 µm sieve (maximum): 0.2% (ISO 787-7).
  • Matter volatile at 105 °C (maximum): 0.5% (ISO 787-2).
  • Loss on ignition (maximum): 3% (ISO 3262-1).
  • Matter soluble in water (maximum): 0.5% (ISO 787-3).
  • pH of aqueous suspension: 6 to 10 (ISO 787-9).
• Conditional requirements (to be agreed between parties): particle size distribution, colour/lightness, oil absorption, resistivity of aqueous extract.
• Analytical methods and updates:
  • Gravimetric BaSO4 determination (simplified in this edition; uses ammonium carbamate in place of sodium carbonate).
  • XRF (added as an alternative method for BaSO4 content).
  • Sampling per ISO 15528 and use of ISO 3696 water for analysis.

Applications and practical value

• Ensures consistent quality and performance of blanc fixe used as an extender/filler in:
  • Paints and coatings, inks and printing, plastics, rubber, adhesives, ceramics and paper.
• Supports quality control, incoming material inspection, specification compliance and supplier contracts.
• Helps formulators control optical properties (whiteness, light scattering), rheology (oil absorption) and chemical stability in finished products.
• Use of standardized test methods (gravimetric, XRF, ISO reference tests) enables comparable results across laboratories and suppliers.

Who should use this standard

• Manufacturers of blanc fixe and other extenders
• QC and analytical laboratories (paint, coatings, plastics)
• Raw material procurement and specification writers
• R&D and formulation teams in coatings, plastics and paper industries
• Regulatory and conformity assessment bodies

Related standards

• ISO 3262-1 (Introduction and general test methods)
• ISO 787 series (general test methods for pigments and extenders)
• ISO 12677 (XRF fused bead method)
• ISO 15528 (sampling)
• ISO 3696 (laboratory water quality)

EN ISO 3262-3:2023 provides the technical and analytical framework needed to specify, test and verify blanc fixe quality reliably for industrial applications.