Overview - EN ISO 17226-3:2011 (Leather formaldehyde emissions)
EN ISO 17226-3:2011 (ISO 17226-3:2011) specifies a laboratory method for the determination of formaldehyde emissions from leather. The method measures formaldehyde released to the gas phase and captured in water, then quantified by high performance liquid chromatography (HPLC) after derivatization with 2,4‑dinitrophenylhydrazine (DNPH). The standard is selective for formaldehyde and also allows observation of other low‑molecular aldehydes and ketones. Results from this emission method are not comparable with extraction‑based methods in ISO 17226‑1/‑2 or ISO 17726‑1.
Key topics and technical requirements
- Principle: Specimen is suspended above demineralized water in a sealed 1 L polyethylene bottle, incubated at (60 ± 2) °C for (180 ± 15) min. Volatile formaldehyde is absorbed into the water, reacted with DNPH, and analyzed by reversed‑phase HPLC (UV detection, ~360 nm).
- Sampling and specimen size: Six specimens, typically (100 × 40) mm, sampled per ISO 2418 and prepared per ISO 2419. Five for emission tests, one for volatile matter (ISO 4684).
- Reagents and preparation: DNPH solution, acetonitrile, and a formaldehyde stock solution (prepared and standardized by iodine/thiosulfate titration) are specified. Water must meet ISO 3696 grade 3.
- Apparatus: 1 L polyethylene bottles with internal hook, oven (60 °C), HPLC system with UV detector, membrane filters (0.45 µm).
- Procedure essentials: 50 ml demineralized water per bottle; post‑incubation water aliquot mixed with acetonitrile and DNPH, allowed to react (60–180 min), filtered and injected to HPLC. Calibration and recovery checks are required.
Applications and users
EN ISO 17226-3:2011 is used for:
- Quality control and batch testing in tanneries and leather goods manufacturing.
- Product safety assessment for consumer goods (footwear, upholstery, garments) where formaldehyde emissions are regulated.
- Independent testing laboratories and certification bodies validating compliance with chemical safety limits.
- Regulatory and forensic testing when measuring airborne formaldehyde release rather than extractable content.
Users include leather chemists, analytical laboratories, product compliance teams, and R&D departments focused on low‑emission leather finishing.
Related standards
- ISO 17226‑1 (HPLC extraction method) and ISO 17226‑2 (colorimetric extraction) - extraction‑based formaldehyde tests.
- ISO 17726‑1 - other extraction methods (not comparable with emission results).
- ISO 2418, ISO 2419 (sampling and sample preparation), ISO 4684 (volatile matter), ISO 3696 (water quality).
Keywords: EN ISO 17226-3:2011, ISO 17226-3, formaldehyde emissions, leather testing, HPLC, DNPH, leather safety testing.