ISO 1833-13:2019

Overview

ISO 1833-13:2019 defines a quantitative chemical analysis method for determining the mass percentage of chlorofibre in textile mixtures using an azeotropic mixture of carbon disulfide (CS2) and acetone. The procedure is applicable after removal of non‑fibrous matter and covers mixtures of certain chlorofibres with a broad range of fibres including wool, silk, cotton, viscose, cupro, modal, lyocell, polyamide, polyester, acrylic, melamine, polypropylene, polyacrylate and glass fibres. The method yields repeatable results suitable for laboratory quality control and compliance verification.

The principle is straightforward: the chlorofibre is dissolved from a known dry mass using the CS2/acetone reagent, the insoluble residue is collected, washed, dried and weighed, and the chlorofibre content is calculated by difference. The standard includes procedural checks (e.g., solubility verification) and safety warnings for the toxic solvent system.

Key Topics

• Scope and applicability: quantitative determination of chlorofibre mass % in specified fibre mixtures.
• Reagent: azeotropic mixture prepared by mixing 555 ml carbon disulfide with 445 ml acetone; ethanol (min. 92 % by volume) used for washing.
• Sample handling: remove non‑fibrous matter prior to analysis; check solubility of the chlorofibre in reagent.
• Procedure highlights:
  • Add 100 ml of reagent per gram of specimen;
  • Shake (20 ± 1) min on a mechanical shaker, decant and repeat until extraction is complete;
  • Collect residue on a weighed filter crucible, wash with ethanol and water, dry and weigh.
• Notes: mixtures with >25 % wool or silk should use ISO 1833-4; mixtures with >25 % polyamide should use ISO 1833-7.
• Calculation: follow ISO 1833-1 general instructions; d = 1.00 (d = 1.01 for melamine and polyacrylate).
• Precision: confidence limits on homogeneous mixtures are ±1 percentage point at 95 % confidence.
• Safety: carbon disulfide is toxic and flammable; follow laboratory safety and ventilation requirements.

Applications

• Quality control and acceptance testing of blended textiles.
• Material composition verification for labeling and regulatory compliance.
• Troubleshooting and failure analysis where accurate quantification of chlorofibre is required.
• Research and development of fibre blends and recycling feedstock characterisation.

Related Standards

• ISO 1833-1 - General principles of quantitative chemical testing.
• ISO 1833-4 - Protein fibre mixtures (hypochlorite) - use when wool/silk >25 %.
• ISO 1833-7 - Polyamide mixtures (formic acid) - use when polyamide >25 %.
• ISO 1833-17 and ISO 1833-21 - Alternative methods for analysing mixtures containing chlorofibres.

This standard provides a practical, reproducible method for laboratories performing quantitative textile analysis and supports robust QC and compliance workflows when working with chlorofibre-containing blends.