Overview
EN ISO 20137:2023 - Leather: Chemical tests - Guidelines for testing critical chemicals in leather is a CEN-adopted ISO standard that provides curated lists of chemicals known to be present in leather and practical guidance on applying leather-specific chemical test methods. Prepared by IULTCS in collaboration with CEN/TC 289, this second edition (superseding 2017) helps manufacturers, laboratories and specifiers select appropriate analytical methods and avoid unnecessary testing of substances irrelevant to leather.
Key topics
- Scope and purpose: Lists chemicals already detected in leather and gives guidance for applying available chemical test methods to set realistic specifications for restricted substances in leather articles.
- Substance categorization: Guidance covers (a) substances conventionally used in leather with no current legal restrictions, (b) substances previously used, and (c) substances not intentionally used but potentially present.
- Examples of chemicals and methods: The standard references leather-specific methods for analytes such as bisphenols (BPA/BPF/BPS), chromium (total and extractable, Cr III), formaldehyde, biocides, glutaraldehyde, brominated flame retardants and heavy metals. ISO test method numbers (e.g., ISO 11936, ISO 5398 series, ISO 17226, ISO 17072, ISO 13365) are cited as suitable leather-specific analytical approaches.
- Analytical matrix considerations: Emphasises that leather is a complex substrate (wet-processed, acidic pH, polymer/oil/dye residues) and that limits and extraction approaches used for aqueous matrices are not always appropriate for leather.
- Limitations and updates: Notes that legal and toxicological landscapes evolve; new substances may emerge and the document cannot cover every potentially critical chemical.
Applications
Who uses EN ISO 20137:2023 and why:
- Tanners and leather manufacturers - to define internal specifications and choose validated leather-specific test methods.
- Testing laboratories - to apply suitable ISO/CEN methods and interpret leather-specific matrix effects.
- Brand owners and purchasers - to require meaningful certificates of compliance and avoid irrelevant tests driven by generic restricted-substance lists.
- Regulatory and compliance teams - to align product testing with up‑to‑date leather standards while optimising analytical costs.
Practical benefits:
- Reduces unnecessary analytical expense by focusing on leather-relevant substances.
- Improves comparability and traceability of test results through recognised ISO/CEN methods.
- Supports supply-chain compliance and product safety specifications.
Related standards
Keywords: EN ISO 20137:2023, leather chemical tests, testing critical chemicals in leather, leather testing standards, restricted chemical substances, leather analysis, IULTCS, CEN.