ISO 17226-2-2018 PDF

Full title and description

ISO 17226-2:2018 — Leather — Chemical determination of formaldehyde content — Part 2: Method using colorimetric analysis. This part specifies a colorimetric (photometric) test procedure for the determination of free and hydrolysis-released formaldehyde in leather extracts; it is intended as a rapid screening or routine QC method rather than a definitive quantification technique.

Abstract

This standard describes a colorimetric method based on the Hantzsch-type reaction (acetylacetone/ammonium acetate) to form a chromophore read at 412 nm. The measured formaldehyde value represents free formaldehyde plus formaldehyde released by hydrolysis in a standard aqueous extract of leather. The method is not absolutely selective for formaldehyde and coloured extracts or other extractables may interfere; for precise quantification the HPLC method in ISO 17226-1 is preferred.

General information

• Status: Published (confirmed).
• Publication date: December 2018.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 59.140.30 (Leather and furs).
• Edition / version: Edition 2 (2018).
• Number of pages: 8 (ISO bibliographic record).

These bibliographic details and the standard’s confirmed status are recorded in the ISO catalogue entry for ISO 17226-2:2018.

Scope

Specifies a procedure to determine the quantity of free formaldehyde and formaldehyde released by hydrolysis in a water extract of leather under standardized extraction conditions. The method uses an aqueous extraction (including a detergent) followed by reaction with acetylacetone/ammonium acetate to produce a chromophore measured at 412 nm. It is intended for routine checks and screening rather than as the reference quantification method, since some leather extract constituents (for example dyes) can interfere at the measurement wavelength.

Key topics and requirements

• Principle: aqueous extraction of leather, reaction of formaldehyde with acetylacetone/ammonium acetate (Hantzsch reaction), measurement of absorbance at 412 nm.
• Extraction conditions: defined extraction solvent and conditions (including use of a wetting agent such as sodium dodecyl sulfate) and temperature control to ensure reproducible release of hydrolysed formaldehyde.
• Reagents and calibration: preparation and verification of formaldehyde standards (or use of certified solutions), reagent blank checks and limits to confirm reagent purity and low background absorbance.
• Interference considerations: coloured extracts and other compounds extracted from leather can react or absorb at 412 nm; procedures (e.g., dimedone test or comparison with HPLC) are referenced to identify or manage interference.
• Applicability and limitation: suitable for rapid screening, routine quality control and comparative testing; not intended as a definitive method for legal disputes or cases requiring highest analytical accuracy — use ISO 17226-1 (HPLC) for precise quantification.

Typical use and users

Used by leather testing laboratories, tanneries and leather product manufacturers for incoming material inspection, production quality control and compliance checks. Also used by conformity assessment bodies and regulatory laboratories as a routine screening tool where quick throughput is needed. For dispute resolution or regulatory limits requiring the most accurate result, testing laboratories typically apply the HPLC-based Part 1 method.

Related standards

ISO 17226 is a multi-part series addressing formaldehyde determination in leather. The principal related document is ISO 17226-1 (HPLC method) — the selective, higher-accuracy procedure used when colour or interfering substances may bias colorimetric results; ISO 17226-1 was revised with a 2021 edition. Earlier versions of ISO 17226-2 (2008) were superseded by the 2018 edition.

Keywords

formaldehyde; leather; colorimetric analysis; Hantzsch reaction; acetylacetone; ammonium acetate; extraction; sodium dodecyl sulfate; photometry; screening method; ISO 17226-2.

FAQ

Q: What is this standard?

A: ISO 17226-2:2018 is the second part of the ISO 17226 series that specifies a colorimetric analytical method for determining free and hydrolysis-released formaldehyde in leather extracts; it is intended primarily as a screening or routine QC procedure.

Q: What does it cover?

A: It covers the extraction of formaldehyde from leather under defined conditions, the chemical reaction (acetylacetone/ammonium acetate) forming a measurable chromophore, calibration and reagent checks, interference considerations and recommended uses and limitations of the colorimetric method.

Q: Who typically uses it?

A: Routine testing and quality-control laboratories in the leather and footwear industry, tanneries, product manufacturers, and conformity assessment bodies that need a rapid screening method for formaldehyde in leather.

Q: Is it current or superseded?

A: ISO 17226-2:2018 is published and its ISO record shows the 2018 edition as confirmed (ISO catalogue entry indicates the publication and confirmation). As of the ISO catalogue review information, this 2018 edition remains the current ISO 17226-2 document. For the related Part 1 HPLC method, a newer ISO 17226-1 edition (2021) is available. Users should verify the ISO catalogue for the latest status before relying on the standard for regulatory or contractual purposes.

Q: Is it part of a series?

A: Yes — ISO 17226 is a series. Part 1 covers the HPLC-based method (selective, high-accuracy) and Part 2 covers the colorimetric screening method; earlier editions of both parts exist and Part 1 was updated in 2021.

Q: What are the key keywords?

A: Formaldehyde, leather, colorimetric analysis, Hantzsch reaction, acetylacetone, extraction, SDS, photometry, screening method, ISO 17226-2.