Overview
ISO 20940:2021 - Leather - Crust full chrome upper leather - Specifications and test methods - defines requirements, sampling and test procedures for crust full chrome upper leather intended for all types of footwear. The standard targets the leather supply chain (tanneries, laboratories, footwear manufacturers and procurement teams) by specifying physical and chemical characteristics, accepted test methods, and packaging/marking and sampling rules to ensure consistent quality and regulatory compliance.
Key topics and requirements
- Scope: Applies to crust full chrome upper leather (tanned with chromium III, fat-liquored and dried before finishing) used in footwear categories such as town, fashion, sports, cold-weather, school and infants’ footwear.
- Physical characteristics: Specifies required tests and performance parameters for:
- Tensile strength and percentage elongation (ISO 3376)
- Tear strength (double-edge tear, ISO 3377-2)
- Distension of grain and grain crack load (ISO 3379)
- Colour fastness to rubbing (ISO 11640)
- Stitch tear resistance (ISO 23910)
- Water vapour permeability and absorption (ISO 14268, ISO 17229)
- Flex resistance (ISO 5402-1)
Note: Numeric limits depend on footwear type and animal species (bovine, goat, sheep) - consult Table 1 in ISO 20940:2021 for exact values.
- Chemical characteristics: Sets contaminant and composition limits, tested by referenced chemical methods:
- Chromium (Cr2O3) content minimum (CrIII) - specified (ISO 5398-1)
- Chromium(VI) content: