ISO 16373-2:2014

Overview - ISO 16373-2:2014 (Textiles - Dyestuffs)

ISO 16373-2:2014 defines a general laboratory method for the determination of extractable dyestuffs from textile materials using a pyridine/water (1:1) extraction. The standard targets a wide range of dye classes, explicitly listing allergenic and carcinogenic dyestuffs (Annexes A and B) that can be analysed by this procedure. The method is part of the ISO 16373 series on dyestuff identification and quantification and is intended for use with chromatographic detection (LC/DAD and/or LC/MS).

Key topics and technical requirements

• Scope: Extraction of dyestuffs from all fibre types using pyridine/water (1:1). Lists of target dyestuffs are provided and expandable.
• Sample preparation: Cut a representative specimen (max. 1.0 g, pieces ≤ 1 cm²) and record mass to 0.01 g.
• Extraction conditions: Add 7.5 ml pyridine/water (1:1) to the sample, heat to (100 ± 2) °C and hold for (35 ± 5) min, then cool to ≤ 40 °C before opening.
• Detection and quantification: Use HPLC with diode array detection (LC/DAD) and/or liquid chromatography–mass spectrometry (LC/MS). Some dyes may be quantified by LC/DAD alone.
• Calibration and reporting: Mixed standards in pyridine/water at 1, 5, 10 and 20 mg/L. Results expressed as mg dyestuff per kg textile (mg/kg). If >100 mg/kg is detected, the dye is considered to be used in the product.
• Reagents and apparatus: Analytical-grade pyridine, acetonitrile, ammonium acetate, tetrabutylammonium dihydrogen phosphate, ISO 3696-grade water; HPLC systems, DAD or MS detectors, appropriate columns and thermal block or sand bath capable of 100 °C.
• Safety: Many listed dyestuffs are allergenic or carcinogenic. Follow national health and safety regulations, MSDS guidance, and use PPE (safety glasses, respirator when handling powders).

Applications - who uses ISO 16373-2 and why

• Textile testing laboratories performing routine compliance and quality control for products (garments, home textiles).
• Manufacturers and dyers verifying extractable dye content and identifying hazardous dyes in supply chains.
• Regulatory and conformity bodies assessing consumer safety related to allergenic or carcinogenic dyestuffs.
• Importers, retailers, and certification bodies checking products against safety specifications and buyer requirements.

Practical benefits include standardized extraction and chromatographic protocols, harmonized reporting (mg/kg), and an extendable list of target dyes for consistent screening across labs.

Related standards

• ISO 16373-1 - General principles of testing coloured textiles for dyestuff identification
• ISO 16373-3 - Method using triethylamine/methanol for some carcinogenic dyestuffs
• ISO 3696 - Water for analytical laboratory use

Keywords: ISO 16373-2:2014, extractable dyestuffs, pyridine-water extraction, LC/DAD, LC/MS, textile dye analysis, allergenic dyes, carcinogenic dyes, HPLC.