ISO 16373-1:2015

Overview

ISO 16373-1:2015 - Textiles - Dyestuffs - Part 1 provides general principles for qualitative testing of coloured textiles to identify dyestuff (colourant) classes. The standard defines colourant classes (dyes vs pigments), describes the relationship between dye types and textile fibres, lists required reagents and apparatus, and gives example procedures for class identification. ISO 16373-1 is the introductory part of the ISO 16373 series and guides laboratories and industry on practical, safety-aware approaches to dyestuff identification and preliminary screening.

Key Topics

• Colourant definitions: distinction between dyes (water-soluble or water-insoluble molecules with fibre affinity) and pigments (water‑insoluble, no fibre affinity).
• Dye classes: descriptions of major dye families and their application methods, including acid dyes, basic (cationic) dyes, direct dyes, disperse dyes, reactive dyes, sulphur dyes, vat dyes, azoic dyes, and mordant dyes.
• Chemist classification: complementary classes such as azo dyes (R–N=N–R') and the note that dye-class terms may overlap between dyers’ and chemists’ classifications.
• Sample preparation and conditioning: reference to ISO 5089 for specimen preparation and ISO/TR 11827 for fibre identification prior to dyestuff testing.
• Reagents and apparatus: list of analytical-grade reagents (e.g., ammonia, acetic acid, sodium hydroxide, sodium formaldehyde sulfoxylate, sodium dithionite, pyridine-water) and basic lab apparatus.
• Example procedures: qualitative workflows including pigment identification, finishing removal, and routine treatments (boiling acid/alkali, reductive/oxidative steps, staining transfers) to distinguish dye classes.
• Safety note: procedures may involve hazardous chemicals; users must follow health, safety and environmental regulations.

Applications / Who Uses It

• Textile testing laboratories performing qualitative dyestuff screening and fibre-dye compatibility checks.
• Manufacturers and quality control teams verifying dye classes and evaluating dyeing processes.
• Regulatory and compliance bodies screening for potential allergenic or restricted dyestuffs prior to quantitative analysis.
• Forensic analysts and conservation specialists identifying colourant types in historical or disputed textiles.
• Practical use cases include initial screening before quantitative extraction (ISO 16373-2 / -3), troubleshooting dyeing problems, and verifying supplier declarations.

Related Standards

• ISO 16373-2 - Determination of extractable dyestuffs (pyridine-water extraction).
• ISO 16373-3 - Determination of certain carcinogenic extractable dyestuffs (triethylamine-methanol extraction).
• ISO 3696 - Water for analytical laboratory use.
• ISO 5089 - Preparation of laboratory test samples for chemical testing.
• ISO/TR 11827 - Fibre identification methods.

Keywords: ISO 16373-1, dyestuff identification, textiles, dye testing, colourant classes, reactive dyes, azo dyes, extractable dyestuffs.