Chemical Determination of Extractable Metal Content in Leather according to ISO 17072-1:2019

This standard specifies a method for determining the amount of extractable metals in leather (such as chromium, lead, arsenic, cadmium, etc.). It measures the metals that can leach out under conditions simulating consumer exposure, such as perspiration or prolonged skin contact.

The leather sample is treated with an extraction solution (usually acidified), and the extract is analyzed using atomic spectrometric techniques to quantify the metals present in the solution.

This method is intended to evaluate the potential health risk from metal migration, not the total content of metals in the leather.

1. Sample Preparation

• A representative leather sample is cut, conditioned, and weighed (usually ~1 g).
• The surface may be lightly ground to increase extraction efficiency.

2. Extraction

• The sample is immersed in an extraction solution, typically a citric acid solution (to simulate skin contact) or acidified artificial sweat.
• The extraction is done at room temperature for a defined period (usually 24 hours) with gentle agitation.

3. Filtration and Analysis

• After extraction, the solution is filtered to remove particles.
• The filtrate is analyzed by:
  • ICP-OES, ICP-MS, or AAS, depending on the metal and required detection level.
• Use of calibration standards and blanks ensures accuracy.

4. Quality Control

• Include method blanks, spiked samples, and reference materials to check performance.

• Results are expressed in mg/kg of leather (wet or dry basis).
• Only extractable metals are reported, not total content.
• The report mentions test conditions, solution type, and pH.