Overview
EN ISO 10601:2008 (ISO 10601:2007) specifies requirements and test methods for micaceous iron oxide (MIO) pigments supplied in dry form and used primarily in protective coatings for steelwork. Adopted by CEN, this standard covers both manufactured and refined natural MIO (specular hematite) and defines essential characteristics, classification, sampling and microscopic test procedures needed to verify pigment quality for corrosion-resistant paints.
Key topics and requirements
- Scope: Applies to MIO pigments used in protective coatings; distinguishes essential requirements and conditional properties agreed between parties.
- Classification by thin‑flake content (lamellar grades):
- Grade A: > 65% thin‑flake (high proportion of lamellar platelets)
- Grade B: 50–65% thin‑flake
- Classification by residue on sieve (types 1, 2, 3):
- 63 µm residue: Type 1 ≤ 5%; Type 2 > 5% to ≤ 15%; Type 3 > 15% to ≤ 35%
- 105 µm residue: ≤ 0.1% for all types
- Essential chemical/physical limits:
- Iron(III) oxide (Fe2O3) content: ≥ 85%
- Matter volatile at 105 °C: ≤ 0.5%
- Matter soluble in water (hot extraction): ≤ 0.5%
- Thin‑flake assessment (microscopy):
- Use optical microscope at ×200 magnification with transmitted light and high sub‑stage illumination.
- Prepare slide with refined linseed oil (ISO 150) or dry spread; count at least 50 particles; use duplicate slide and average.
- Thin flakes appear as red translucent platelets; thicker/granular particles appear black.
- Conditional requirements (by agreement):
- pH within ±1 unit of reference pigment (ISO 787‑9)
- Oil absorption within ±15% of reference pigment (ISO 787‑5)
- Total calcium oxide to be agreed (ISO 1248)
- Sampling & reporting:
- Sampling per ISO 15528; test report must identify product, reference ISO 10601, results, deviations and test dates.
Applications and users
- Practical use: Corrosion‑resistant paints for steel structures, where overlapping MIO platelets provide barrier protection, UV shielding and improved film strength.
- Primary users:
- Pigment manufacturers (quality control, product specification)
- Paint and coating formulators (raw material selection)
- Testing laboratories and certification bodies (compliance testing)
- Specifiers, procurement teams and corrosion engineers (material acceptance criteria)
Related standards
- ISO 1248 - Iron oxide pigments
- ISO 3549 - Zinc dust pigments for paints
- ISO 787 series - General methods of test for pigments and extenders (parts 2, 3, 5, 9 referenced)
- ISO 150 - Refined linseed oil for paints and varnishes
- ISO 15528 - Sampling of paints, varnishes and raw materials
Keywords: micaceous iron oxide, MIO pigments, ISO 10601, EN ISO 10601:2008, protective coatings, steelwork, thin‑flake, lamellar pigment, pigment specifications, test methods.
