Overview
ISO 105-E05:2010 - Textiles - Tests for colour fastness - Part E05: Colour fastness to spotting: Acid - specifies a standardized method to evaluate how textile colours resist the action of dilute organic and mineral acids. The standard provides up to four test severities (selectable depending on fibre type) and describes spotting, assessment (wet and dry), reagents, specimen preparation and reporting requirements. Keywords: ISO 105-E05, colour fastness, acid spotting test, textiles, colour fastness tests.
Key topics and technical requirements
- Scope: Determines resistance of all kinds of textiles and forms to dilute organic and mineral acids.
- Test principle: Drops of acid solution are placed on the specimen and rubbed with a rounded glass rod to ensure penetration; colour change is assessed while wet and after drying.
- Reagents (examples given in the standard):
- Acetic acid: 300 g glacial acetic acid per litre
- Hydrochloric acid: 350 g concentrated HCl per litre
- Sulfuric acid: 50 g concentrated H2SO4 per litre
- Tartaric acid: 100 g crystalline tartaric acid per litre (used especially for acetate fibres)
- Grade 3 water for dilution
- pH ranges (from Table 1): acetic 1.8–2.4, HCl 0.1–0.3, sulfuric 0.6–0.8, tartaric 1.5–1.8.
- Specimen size: typically 40 mm × 100 mm for fabrics; procedures for yarn or loose fibre are specified.
- Assessment methods: Visual comparison with the ISO 105-A02 grey scale or instrumental assessment per ISO 105-A05. Wet assessment can be made after 10 minutes if relevant.
- Procedure highlights: controlled spotting (≈20 mm spot), limit solution volume for water-repellent fabrics (≤0.5 ml), drying at room temperature before final assessment.
- Reporting: reference to ISO 105-E05:2010, sample identification, numerical grey-scale or instrumental results (dry and optionally wet), water-spotting result (per ISO 105-E07), and any deviations from the procedure.
Applications and users
- Who uses it: textile and apparel manufacturers, dye houses, quality control laboratories, testing laboratories, R&D teams, procurement and compliance officers.
- Practical uses:
- Quality control of dyed textiles and finished garments
- Dye/fibre selection and evaluation during product development
- Verifying resistance to accidental acidic spills (industrial/consumer use)
- Supporting claims of colour performance and regulatory or contractual compliance
- Troubleshooting staining or fading issues linked to acid exposure
- Benefits: reproducible, comparable results across suppliers and labs; helps reduce returns, improve durability and ensure consistent colour performance.
Related standards
- ISO 105-A01 (general principles of testing)
- ISO 105-A02 (grey scale for assessing change in colour)
- ISO 105-A05 (instrumental assessment)
- ISO 105-E07 (colour fastness to spotting: Water)
For consistent testing and SEO relevance, include terms such as ISO 105-E05, acid spotting test, textile colour fastness, colourfastness testing and spotting resistance when documenting or searching for guidance.