Overview
EN ISO 27587:2021 - Leather - Chemical tests - Determination of free formaldehyde in process auxiliaries specifies an analytical procedure to quantify free formaldehyde released from leather process auxiliaries when heated under dynamic, inert dry conditions. Results are reported in mg/kg. The method was prepared by IULTCS in cooperation with CEN and replaces the 2009 edition.
Key topics and technical requirements
- Principle: heat the sample in an inert atmosphere; capture released formaldehyde on a 2,4-dinitrophenylhydrazine (DNPH) cartridge; elute with acetonitrile and analyse by HPLC with UV or diode array detection (DAD).
- Sample conditions: typical sample mass 0.1–2 g (adjustable for liquids); no dilution of the sample; heat in a U‑tube assembly with sea sand packing.
- Temperature & atmosphere: thermostatic oil bath at (90 ± 3) °C; inert nitrogen flow (nitrogen purity 4.6) with controlled flow (example purge 500 ml/min during system setup).
- Reagents & calibration: DNPH cartridges (example capacity 6 400 µg carbonyls), formaldehyde‑2,4‑DNPH analytical standard and calibration standards prepared by dilution; formaldehyde solution S1 and S2 used for procedure control.
- Apparatus: U‑tube calcium chloride configuration, flow meter, HPLC (RP‑C18 column), 0.45 µm syringe filters, silicone oil bath, PTFE stopcock grease free of formaldehyde.
- Quality control: procedure includes reagent checks for absence of formaldehyde, calibration and control solutions, and annexes on HPLC conditions and method reliability.
- Output: calculated formaldehyde concentration expressed in mg/kg sample.
Applications and users
EN ISO 27587:2021 is intended for laboratories and organizations involved in the leather supply chain that need accurate measurement of free formaldehyde in process auxiliaries:
- Tannery and leather chemical manufacturers (product QC)
- Independent testing and conformity assessment laboratories
- Procurement and compliance teams verifying supplier declarations
- Environmental health and safety (EHS) and regulatory testing where formaldehyde release is a concern
- R&D groups developing low‑formaldehyde auxiliaries
This method is particularly useful when the interest is the amount of formaldehyde released under heating (dynamic conditions) rather than total bound/formaldehyde derivatives.
Related standards
- ISO 3696 - Water for analytical laboratory use (referenced for water quality)
- EN ISO 27587:2010 - previous edition (superseded)
Keywords: EN ISO 27587:2021, free formaldehyde, leather process auxiliaries, DNPH cartridge, HPLC analysis, formaldehyde determination, chemical tests leather, mg/kg.
