ISO 105-Z01:1993 PDF

Overview

ISO 105‑Z01:1993 is part of the ISO 105 series on textile colour fastness. It specifies a laboratory test method for determining the effect of hexavalent chromium salts in the dye‑bath on the colour (shade) of dyes applied to wool. The procedure compares dyeings made with and without a potassium dichromate reagent and rates the shade difference using the ISO grey scale for change in shade. The standard is intended for quality control, formulation assessment and evaluation of shading effects caused by chromium salts in dyeing.

Key topics and requirements

• Scope: Test method applicable to wool to assess the influence of chromium (hexavalent) salts present in the dye bath.
• Test principle: Two identical dyeings are produced - one control and one performed in the presence of potassium dichromate - and the difference in shade is evaluated visually against the grey scale (ISO 105‑A02).
• Reagents and apparatus:
  • Potassium dichromate (K2Cr2O7) reagent specified by the standard.
  • Two lightweight, undyed wool specimens sized for laboratory dyeing.
  • Two dye baths of usual composition for the dye under test.
• Procedures:
  • Dye two specimens to the recommended shade using normal auxiliaries and bath ratio.
  • At the end of dyeing add the specified amount of potassium dichromate to one bath (the standard provides example additions corresponding to 1% or 2% calculated relative to the mass of the wool in the examples given) and continue boiling for 60 minutes.
  • Compare the two dyed specimens and assign a colour change rating using the ISO grey scale.
• Test report: Must include the ISO reference, the dye and dyeing method used, concentration of dye, and the colourfastness rating corresponding to the observed shade difference.

Applications and users

• Textile testing laboratories performing colour fastness assessments.
• Wool dyers and mills conducting quality control and batch validation.
• Dye manufacturers and R&D teams evaluating formulation robustness and the sensitivity of dyes to chromium contamination.
• Buyers and supply‑chain quality managers validating supplier performance where chromium residues or shading processes may affect final shade.
• Environmental/chemical safety teams monitoring potential impacts of hexavalent chromium on product appearance.

Related standards

• ISO 105‑A02 - Grey scale for assessing change in shade (used for evaluation).
• ISO 105‑A01 and other parts of the ISO 105 series - general principles and related colour fastness methods.

Keywords: ISO 105‑Z01, colour fastness, chromium salts, potassium dichromate, dye bath, wool, grey scale, textile testing, shade change.