Overview
EN ISO 25089:2025 - Leather: Tests for colour fastness to sea water (ISO 25089:2025) specifies a laboratory method to determine how leather of all kinds resists colour change and staining when exposed to sea water. Published by CEN and prepared by IULTCS in cooperation with CEN/TC 289, the standard applies at all stages of leather processing and is endorsed as a European standard.
Key topics and technical requirements
- Scope and principle: The test measures both the change in colour of a leather specimen and staining of an adjacent fabric after exposure to a sodium chloride solution that simulates sea water.
- Test medium: Sodium chloride solution (30 g/l) prepared using laboratory-grade water (ISO 3696).
- Specimen preparation: Typical test-piece sizes ~100 mm × 40 mm; finished leather can be tested intact or with the finish deliberately broken (abrasion using P180 abrasive paper).
- Apparatus and conditions:
- A pressure apparatus applying 12.5 kPa ±1.0 kPa via a defined weight-piece and inert plates (glass/acrylic).
- Vacuum treatment in a desiccator (≈5 kPa) to remove entrapped air from specimens.
- Drying in an oven at 37 °C ± 2 °C.
- Adjacent fabrics: Multifibre (ISO 105-F10) or single-fibre adjacent fabrics per ISO 105-F01…F07 to evaluate staining.
- Assessment methods: Visual grey scales for change in colour and staining (ISO 105-A02, A03) or instrumental evaluation (spectrophotometer/colorimeter per ISO 105-A04/A05).
- Documentation: Test report must record specimen preparation, whether finish was broken, apparatus used, test conditions, and evaluation results. The standard also includes precision guidance and commercial sources for apparatus (Annex A).
Practical applications and users
EN ISO 25089:2025 is used to:
- Verify product performance for footwear, upholstery, garments, automotive leather, and leather goods exposed to marine environments.
- Support quality control in tanneries, leather finishing plants and contract testing laboratories.
- Provide objective data for material specifications, supplier approvals, and claims of sea-water colour fastness.
- Aid R&D teams in developing dyes, finishes and treatments with improved sea-water resistance.
Primary users:
- Leather manufacturers and finishers
- Independent testing laboratories and certification bodies
- Product designers, specifiers, and procurement professionals in marine and outdoor sectors
- Regulatory and compliance personnel concerned with material durability and consumer information
Related standards
- ISO 7906 - General principles of leather colour fastness testing
- ISO 105 series (A02, A03, A04, A05, F01–F10) - Grey scales, adjacent fabrics, instrumental assessment
- ISO 2418 - Specimen sampling and preparation
- ISO 3696 - Water for analytical laboratory use
Keywords: EN ISO 25089:2025, colour fastness to sea water, leather testing, sea water fastness, ISO 25089:2025, leather colour fastness, adjacent fabric, sodium chloride solution.
