Overview
ISO 17072-1:2019 - Leather - Chemical determination of metal content - Part 1: Extractable metals - specifies a laboratory method to quantify extractable metals in leather. The method uses extraction with an acid artificial-perspiration solution followed by instrumental determination (ICP-OES, ICP-MS, AAS or atomic fluorescence). Results are reported on the leather’s dry mass and the method is particularly suitable for measuring extractable chromium from chromium‑tanned leathers.
Key topics and technical requirements
- Extraction conditions: leather sample (typically 2 g) is extracted at (37 ± 2) °C for 4 h ± 5 min in an acid artificial‑perspiration solution prepared in accordance with ISO 105‑E04 (pH 5.5 ± 0.1). For limited sample amounts, 1 g leather with 50 ml solution is permitted.
- Artificial perspiration composition: L‑histidine monohydrochloride, sodium chloride and sodium dihydrogen phosphate; pH adjusted with 0.1 mol/l NaOH (details per ISO 105‑E04).
- Analytical methods: filtered extracts are acidified (e.g., 5 % v/v nitric acid addition) and analysed by:
- Scope of metals: method applies to many metals including Al, As, Ba, Ca, Cd, Cr, Co, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Ti, V, Zn, Zr and others listed in the standard.
- Reporting and calculations: results expressed as mass fraction (mg/kg) on dry matter; blank controls and proper dilution factors required.
- Quality considerations: use trace‑metal‑clean apparatus, follow ISO sampling and sample preparation (ISO 2418, ISO 4044), and observe acid handling safety warnings. Annex A provides interlaboratory results and quantification limits (ICP‑OES).
Applications and users
- Who uses it: leather testing laboratories, manufacturers of leather goods, quality assurance teams, regulatory bodies, product compliance and safety assessors, and environmental/occupational chemists.
- Practical uses:
- Verify compliance with metal content regulations and safety limits for consumer products (e.g., footwear, garments).
- Monitor extractable chromium and other metals from tanning and finishing processes.
- Support supplier quality control and raw material screening.
- Provide data for risk assessment of skin contact and potential metal release under perspiration-like conditions.
Related standards
Normative references in ISO 17072-1:2019 include ISO 105‑E04, ISO 2418, ISO 3696, ISO 4044, ISO 4684, ISO 11885, ISO 15586, ISO 17294‑2 and ISO 17852 - all relevant for sampling, preparation and instrumental methods.
Keywords: ISO 17072-1:2019, extractable metals, leather testing, acid artificial‑perspiration, ICP‑OES, ICP‑MS, AAS, atomic fluorescence, chromium‑tanned leather, metal content determination.