ISO 11641:2012

Overview

ISO 11641:2012 specifies a standardized laboratory method for determining the colour fastness to perspiration of leather at all stages of processing. The method simulates human perspiration using an artificial perspiration solution (primarily alkaline, pH 8.0 ± 0.1) and assesses both change in leather colour and staining of adjacent fabrics. It is particularly relevant for gloving, clothing and lining leathers and for uppers of unlined shoes.

Key topics and technical requirements

• Test principle: Leather and adjacent fabric are soaked in artificial perspiration, assembled as a composite specimen, pressed under constant pressure and heated; after drying, colour change and staining are evaluated.
• Artificial perspiration:
  • Alkaline solution (per litre): 5.0 g NaCl, 5.0 g tris(hydroxymethyl)aminomethane (TRIS), 0.5 g urea, 0.5 g nitrilotriacetic acid; adjusted to pH 8.0 ± 0.1 with 2 mol/l HCl.
  • Acid solution (if required): composition and pH 5.5 ± 0.2 as specified in ISO 105‑E04; prepared fresh daily.
• Apparatus & conditions:
  • Loading weight-piece (approx. 5 kg; cross-section ~115 × 60 mm) applying 12.5 ± 1.0 kPa pressure between inert plates.
  • Vacuum step during wetting to ~5 kPa (50 mbar) held for cycles.
  • Oven at 37 °C ± 2 °C for 180 min ± 10 min.
• Specimen sizes & preparation:
  • Leather specimen ≈ 100 × 40 mm (or 120 × 50 mm for finish-broken preparation).
  • Adjacent fabric(s) ≈ 100 × 40 mm (multifibre per ISO 105‑F10 or single-fibre per ISO 105‑F01–F07).
  • Option to test finish intact or intentionally “broken” (abrasive treatment) - report must state which.
• Evaluation:
  • Visual assessment with grey scales for change in colour (ISO 105‑A02) and staining (ISO 105‑A03), or instrumental assessment per ISO 105‑A04/A05.
  • Typical inter-person precision: ±0.5 grey scale units.
• Reporting: Results must reference ISO 11641 and include leather type, finish status, perspiration type, grey scale ratings for staining and colour change, and deviations from procedure.

Applications

• Quality control and acceptance testing in tanneries and leather finishing operations
• Performance specification for leather goods (gloves, clothing, linings, footwear uppers)
• Product development and change control to evaluate dye fixation and resistance to human perspiration
• Third‑party laboratory testing for supply-chain compliance

Who uses this standard

• Leather manufacturers and finishers
• Footwear, glove and apparel product developers
• Independent testing laboratories and certification bodies
• R&D teams working on dyes, finishes and leather treatments

Related standards

• ISO 105‑A01, A02, A03, A04, A05 (colour fastness test principles and assessment)
• ISO 105‑E04 (textile perspiration method)
• ISO 105‑F01…F10 (adjacent fabric specifications)
• ISO 2418 (leather sampling location)
• ISO 3696 (laboratory water quality)

Keywords: ISO 11641:2012, colour fastness to perspiration, leather testing, artificial perspiration solution, grey scale assessment, leather quality control.