Overview
EN ISO 105‑G01:2016 - "Textiles - Tests for colour fastness - Part G01: Colour fastness to nitrogen oxides" is a CEN-endorsed ISO method for evaluating the resistance of textile colours to nitrogen oxides (NOx) produced by combustion (gas, coal, oil) or generated when air passes over heated filaments. The standard defines test apparatus, sample preparation, two exposure methods (differing in severity), assessment criteria and reporting requirements for textiles in all forms.
Key topics and requirements
- Two test methods: a one‑cycle and a three‑cycle exposure; one or both are used depending on initial results (see clause 7.2.4).
- Exposure principle: specimens and test‑control fabrics are exposed in a closed chamber to nitric oxide until a predetermined degree of fading is reached; results are assessed with the grey scale (ISO 105‑A02).
- Test‑control fabrics: standard reference fabrics dyed with Disperse Violet 1 (0.4 % owf) and Disperse Blue 56 (0.8 % owf) are specified to monitor severity and reproducibility.
- Apparatus & reagents: exposure chamber (Annex A), nitric oxide supply (cylinder or generator - Annex B), syringe or gas burette for delivery, sulfuric acid, sodium nitrite, sodium hydroxide, urea solution, undyed adjacent fabric, and a fan (rotational frequency 200–300 min‑1).
- Specimen size & conditioning: typical specimen size 40 × 100 mm; up to 12 specimens per run. Conditioning and testing atmosphere per ISO 139: (20 ± 2) °C and (65 ± 4) % RH.
- Safety: nitric oxide is toxic; maximum recommended workplace concentration noted (≈6.7 mg/m3). Appropriate ventilation and controls are required.
- Assessment & reporting: colour change assessed with ISO 105‑A02 grey scale; test report must record method used, controls, atmosphere, and result.
Practical applications
- Quality control and acceptance testing for dyed fabrics and finished textile products exposed to combustion gases or heated elements (e.g., apparel, upholstery, technical textiles, automotive interiors).
- Comparative evaluation of dyes, dyeing processes and finishes for NOx resistance.
- Product conformity checks for manufacturers, independent testing laboratories and buyers specifying colour‑fastness performance.
Who should use this standard
- Textile manufacturers and dye houses
- Independent textile testing laboratories and QC departments
- Product developers for automotive, home textiles, protective clothing and technical textiles
- Procurement and compliance professionals specifying colour‑fastness to combustion gases
Related standards
- ISO 105‑A02 - Grey scale for assessing change in colour
- ISO 105‑F02 - Adjacent fabrics specification (cotton & viscose)
- ISO 139 - Standard atmospheres for conditioning and testing
- ISO 3696 - Water for analytical laboratory use
EN ISO 105‑G01:2016 is essential when evaluating how textile colours hold up to NOx exposure and for ensuring reproducible, comparable test results across labs and supply chains.