ISO 25089:2025 – Colour Fastness to Sea Water Test Instrument for Leather

ISO 25089:2025 - Leather: Tests for colour fastness - Colour fastness to sea water specifies a laboratory method to determine how leather of all types resists colour change and staining when exposed to sea water (saltwater). Developed with IULTCS, this standard covers specimen preparation, test apparatus, procedures, and evaluation to ensure consistent and comparable results for manufacturers and testing laboratories.

Key Topics and Technical Requirements

Test Principle

A leather specimen and a standard test fabric are immersed in a 30 g/L sodium chloride solution.

Specimens are pressed together under controlled pressure and temperature to simulate saltwater exposure and transfer.

After drying, colour change and staining are evaluated using grey scales.

Apparatus & Materials

Stainless steel test frame with ~5 kg rectangular weight (~115 × 60 mm) applying 12.5 ± 1.0 kPa.

Inert plates (glass or acrylic) for uniform pressing.

Oven capable of 37 ± 2 °C.

Vacuum container (~5 kPa) to remove trapped air from specimens.

ISO-specified reference fabrics (multifibre or single-fibre).

Fine abrasive paper (P180) for optional finish removal.

Specimen Preparation

Typical size: ~100 × 40 mm.

Optional abrasion of leather finish; finish removal must be documented.

Procedure Parameters

Immersion with vacuum cycles, preheated weight.

Pressing composite in oven for 180 ± 10 min at 37 °C.

Air drying prior to evaluation.

Evaluation & Instrumentation

Visual assessment under D65 illuminant using ISO grey scales: ISO 105-A02 (colour change) and ISO 105-A03 (staining).

Optional instrumental measurement with spectrophotometer or colorimeter per ISO 105-A04 / A05.

Reporting

Include reference to ISO 25089:2025, leather description, finish removal status, and grey-scale ratings for colour change and staining by fibre type.

Applications and Users

Quality control in tanneries and leather finishing plants to verify saltwater fastness.

Footwear, marine upholstery, automotive, and outdoor leather product manufacturers.

Independent testing laboratories for compliance testing, supplier qualification, and R&D.

Specification writers and procurement teams requiring objective test data for contracts and performance claims.

Related Standards

ISO 7906:2022 – General principles for leather colour fastness testing.

ISO 2418 – Specimen location and preparation.

ISO 3696 – Laboratory water quality.

ISO 105 series (A02 / A03 / A04 / A05, F01–F10) – Grey scales, instrumental methods, and reference fabrics.

Qinsun Instruments is a professional instrument equipment manufacturer, providing one-stop solutions for all leather testing and laboratory needs.

2026-01-07 17:59