Overview
EN ISO 4684:2005 - Leather: Chemical tests - Determination of volatile matter (ISO 4684:2005) specifies a laboratory method to measure the volatile matter lost from leather when dried at controlled temperature. The method applies to all leather types and expresses volatile matter as the percentage mass loss on drying. It is important to note that this test does not provide the exact moisture content of leather because other volatile substances can evaporate and fats/tannins may oxidize during drying; some absorbed water may also remain.
Key topics and requirements
- Principle: Finely ground leather is dried in an oven at 102 °C ± 2 °C to constant mass; volatile matter = percentage mass loss.
- Sample preparation: Follow sampling location and sample preparation guidance (ISO 2418 and ISO 4044 where possible); if sampling from finished products, report sampling details.
- Apparatus:
- Flat weighing vessels (preferably with ground glass stoppers) or open dishes
- Oven controlled at 102 °C ± 2 °C
- Analytical balance with 0.001 g accuracy
- Desiccator for cooling
- Procedure:
- Tare dry vessel; weigh ~3 g sample to nearest 0.001 g
- Dry 5 h at 102 °C ± 2 °C, cool 30 min in desiccator, weigh
- Repeat drying cycles of 1 h until further loss ≤ 3 mg (0.1% of sample) or total drying = 8 h
- Calculation: w (%) = 100 × (m1 − m2) / m1, where m1 = initial mass, m2 = mass after drying.
- Repeatability: Duplicate determinations should not differ by more than 0.2% (of original mass); if they do, repeat testing.
- Annex A (informative): For leathers with large amounts of oxidizable fats, determine extractables by ISO 4048 (dichloromethane), dry the extracted residue and subtract extractables to obtain volatile matter attributable to moisture/volatiles.
Applications and who uses this standard
- Leather manufacturers and tanners for quality control and batch release testing
- Independent test laboratories and QC labs validating material specifications
- Product developers and R&D teams evaluating treatments, tanning processes or drying methods
- Compliance officers and procurement ensuring material consistency and conformity with client requirements
Practical uses include checking drying performance, comparing processes, documenting production quality, and supporting specifications for leather goods.
Related standards
- ISO 2418 - Sampling location for leather testing
- ISO 4044 - Preparation of chemical test samples
- ISO 4048 - Determination of matter soluble in dichloromethane (extractables)
Keywords: EN ISO 4684:2005, volatile matter, leather chemical tests, moisture content, leather testing, drying at 102 °C, IULTCS, CEN.
