ISO 3262-1:2020

Overview - ISO 3262-1:2020 (Extenders: specifications and methods of test)

ISO 3262-1:2020 defines the term extender (also called filler) and specifies the general test methods required for most subsequent parts of the ISO 3262 series. It provides standardized procedures and definitions used when assessing extenders for paints, related coating materials and other applications. The document sets out sampling rules and core laboratory methods so that more specific parts of ISO 3262 can reference consistent test protocols.

Key topics and technical requirements

• Definitions and scope
  • Clear definition of “extender” (matière de charge) and guidance on terminology and use.
• Sampling
  • Requirement to obtain a representative test sample in accordance with ISO 15528.
• General test methods
  • Colour comparison: Visual arbitration method and options for instrumental measurement (reference to CIE Lab* and ISO 11664-4); procedure for wet and dry comparison on diffused glass.
  • Loss on ignition (LOI): Procedure for determining volatile/decomposable content by calcination in a muffle furnace at (1000 ± 25) °C until constant mass; cooling in a desiccator and calculation of percentage loss on ignition.
  • Calcium and magnesium content: Wet-chemical titrimetric methods using EDTA (standardized solution), with indicators (Calcon and Mordant Black II), pH adjustments and expression of results as carbonate equivalents. Reagent specifications (e.g., HCl, KOH, ammonia, EDTA) and requirement for analytical-grade reagents and ISO 3696 quality water are included.
• Laboratory equipment and references
  • Use of standard laboratory glassware per ISO 385, 648, 1042 and 3819; cross-references to ISO 787-2 for pre-drying and volatile matter determination.

Practical applications and users

• Typical users:
  • Quality control laboratories in pigment, filler and paint manufacturing.
  • Coating formulators and R&D teams validating filler performance in paints and coatings.
  • Procurement and specification writers creating material acceptance criteria.
  • Regulatory and testing bodies assessing compliance and material characterization.
• Practical benefits:
  • Ensures repeatable, comparable test results across suppliers and industries.
  • Provides baseline methods used by later ISO 3262 parts to specify requirements for individual extenders (e.g., calcium carbonate, kaolin).
  • Helps manufacturers and buyers verify composition (LOI, Ca/Mg) and visual appearance (colour) before use in formulations.

Related standards

• ISO 3262 series (subsequent parts for specific extenders)
• ISO 15528 (sampling)
• ISO 787-2 (determination of volatile matter)
• ISO 11664-4 and ISO 18314-1 (colour measurement methods)
• ISO 3696 (laboratory water quality)

Keywords: ISO 3262-1:2020, extenders, fillers, specifications, methods of test, loss on ignition, EDTA titration, paint fillers, coatings quality control.