EN ISO 3262-5:2023 PDF

Overview

EN ISO 3262-5:2023 - "Extenders - Specifications and methods of test - Part 5: Natural crystalline calcium carbonate" is a CEN-endorsed ISO standard that specifies requirements and test methods for natural crystalline calcium carbonate (derived from limestone and marble). It updates and supersedes the 1998 edition and is intended for use in quality control, procurement and conformity assessment of calcium carbonate extenders used in pigment and extender applications.

Key topics and requirements

• Scope: Defines essential and conditional requirements and associated test methods for natural crystalline CaCO3.
• Grades and chemical purity: Four grades (A–D) are defined by minimum calcium carbonate content: Grade A 99%, B 98%, C 95%, D 90% (mass fraction, tested per ISO 3262-1).
• Essential characteristics (examples):
  • Matter volatile at 105 °C: ≤ 0.4% (ISO 787-2)
  • Loss on ignition: maximum 46% (ISO 3262-1)
  • Matter soluble in water: typically ≤ 0.5% (ISO 787-3 or ISO 787-8; method to be agreed where noted)
  • pH of aqueous suspension: 8–10 (ISO 787-9)
  • Matter insoluble in hydrochloric acid: grade-dependent maxima 1% (A), 2% (B), 8% (C/D) - determined by the procedure specified in Clause 6 of EN ISO 3262-5:2023
• Test procedure for matter insoluble in HCl: Weigh ~10 g sample, treat with ~25% HCl and water, boil, filter through 0.8 µm membrane, wash, dry at (105 ± 2) °C and calculate percentage residual insoluble matter relative to the original sample mass.
• Conditional requirements: Particle size (instrumental method ISO 8130-13), residue on 45 µm sieve (ISO 787-7), colour/lightness and resistivity of aqueous extract (ISO 3262-1, ISO 787-14) - to be agreed between parties.
• Sampling and reporting: Sampling per ISO 15528; test reports must identify product, cite ISO 3262-5:2023, list results, methods, deviations and date.

Applications and users

• Practical applications: Natural crystalline calcium carbonate extenders are commonly used in coatings and paints, plastics, paper, adhesives, rubber and other formulated products where particle chemistry, purity, particle size and electrical properties affect performance.
• Who uses this standard: Manufacturer quality control, incoming inspection, laboratory analysts, product specifiers, procurement teams, regulatory bodies and standards committees.

Related standards

• ISO 3262-1 (general test methods for extenders)
• ISO 787 series (general test methods for pigments and extenders)
• ISO 8130-13 (particle size by laser diffraction)
• ISO 15528 (sampling)
• ISO 18451-1 (terminology)

This standard is essential for ensuring consistent quality, reproducible testing and clear contractual specifications for natural crystalline calcium carbonate extenders. Keywords: EN ISO 3262-5:2023, natural crystalline calcium carbonate, extenders, calcium carbonate specifications, test methods, matter insoluble in hydrochloric acid, particle size.