ISO 20137:2023

Overview

ISO 20137:2023 - Leather - Chemical tests - Guidelines for testing critical chemicals in leather provides practical guidance and curated lists of chemicals known to occur in leather and explains how to apply leather-specific chemical test methods. Designed to help set realistic specifications for restricted substances, the standard reduces unnecessary analytical costs by identifying substances that are relevant (and those that are not) to leather testing. This second edition (2023) updates test references and adds substances such as bisphenols, glutaraldehyde and brominated flame retardants.

Key topics

• Scope and purpose
  • Lists chemicals detected in leather and groups them by relevance (currently used, previously used, not conventionally used).
  • Provides guidance on selecting appropriate analytical methods for leather matrices.
• Chemical groups covered
  • Substances used by the leather industry (e.g., chromium III tanning salts, formaldehyde, biocides, heavy metals, bisphenols, glutaraldehyde).
  • Substances historically used but now unlikely at regulated limits (e.g., alkylphenols, phthalates, chlorophenols, chlorinated paraffins, PAHs).
  • Substances not intentionally used but potentially present as contaminants.
• Analytical considerations
  • Emphasis on leather as a complex matrix (effects of wet processing, acids, polymers and dyes) and the need to use leather-specific ISO/CEN methods rather than methods developed for other industries.
  • Examples of referenced test methods: ISO 11936, ISO 5398 series, ISO 17226 series, ISO 17072 series, ISO 13365, ISO 4045 and others cited for extractable/total metals, formaldehyde, biocides and pH.
• Limitations
  • Note that evolving legal and toxicological landscapes mean the document cannot list every potentially critical substance; it targets those established as relevant to leather.

Applications

• For manufacturers, tanneries and finishing houses: develop realistic product specifications and quality control plans for restricted chemicals.
• For testing laboratories: choose validated leather-specific methods and avoid irrelevant analyses that increase cost and turnaround time.
• For brand owners, specifiers and procurement teams: assess supplier compliance and request appropriate certificates of conformity based on leather-relevant tests.
• For regulators and standards bodies: reference leather-specific guidance when interpreting cross-industry restricted substance lists.

Related standards

• ISO 15115 - Leather vocabulary
• EN 15987 - Leather terminology
• Numerous ISO/CEN leather test methods referenced throughout ISO 20137:2023 (see standard for full list and normative references).

Keywords: ISO 20137:2023, leather chemical tests, testing critical chemicals in leather, leather testing standards, restricted chemicals, chemical analysis of leather, leather industry compliance.