Overview
EN ISO 11908:2025 - “Binders for paints and varnishes - Amino resins - General methods of test” is a CEN-adopted ISO standard that specifies general test methods for amino resins and their solutions when used as binders in paints, varnishes and related products. The 2025 edition supersedes the 1998 version and consolidates test methods and definitions used for quality control, specification and regulatory purposes across Europe and internationally.
Key topics and technical requirements
This standard defines the properties to be measured and the standardized test methods to be used, including:
- Colour - measured by ISO 6271 (platinum‑cobalt) or ISO 4630 (Gardner).
- Viscosity - according to ISO 3219 (all parts).
- Non‑volatile matter - determined by ISO 3251.
- Flash point - ISO 1523 or ISO 3679.
- Density - ISO 2811‑1 (pycnometer method).
- Free‑formaldehyde content - ISO 11402:2004, sulfite procedure.
- Acid value - ISO 2114 (for resin solutions).
- Compatibility with hydrocarbons - a normative Annex A turbidity titration using an 80:20 heptane:toluene mixture (heptane CAS 142‑82‑5; toluene CAS 108‑88‑3). The compatibility characteristic c is calculated as c = V/m (mL of solvent mixture per g of resin solution).
- Sampling - reference to ISO 15528 for representative sampling.
Precision data given for the hydrocarbon compatibility test:
- Repeatability limit r = 5 % (single lab, short interval).
- Reproducibility limit R = 10 % (different labs).
Practical applications and users
EN ISO 11908:2025 is intended for:
- Manufacturers of amino resins - to support product specification and quality control.
- Paint and varnish formulators - to assess binder properties that affect formulation stability and performance.
- Quality control and testing laboratories - for standardized methods used in acceptance testing and inter‑laboratory comparison.
- Regulatory and procurement teams - for compliance, sourcing, and material verification.
- R&D teams - to compare resin variants and screen for compatibility with solvents and formulation components.
Typical uses include routine QC testing, specification of incoming binders, troubleshooting formulation incompatibility, and documenting product data sheets.
Related standards
EN ISO 11908:2025 references and works with other standards, including:
Using EN ISO 11908:2025 helps ensure consistent, repeatable testing of amino resin binders and improves comparability of results across laboratories and suppliers.
