EN ISO 14362-2 Determination of the Use of Certain Azo Dyes Accessible by Fiber Extraction

The standard EN ISO 14362-2 Textiles - Methods for the determination of certain aromatic amines derived from azo dyes - Part 2: Determination of the use of certain azo dyes accessible by extraction from fibres", based on a European standard and subsequently published by the International Organization for Standardization (ISO), describes a procedure for detecting the use of certain azo dyes that cannot be used in the production or processing of certain goods made from synthetic fibres dyed with extractable dyes. For the direct test method, see EN ISO 14362-1. For certain fibre blends, both parts of this standard may need to be applied.

Certain azo dyes may release one or more of the aromatic amines prohibited under Directive 2002/61/EC by reductive cleavage of the azo groups. These aromatic amines are listed in the table entitled "Aromatic amines prohibited under Directive 2002/61/EC" provided in the standard (22 items).

The colorant is removed from the fiber in the headspace using suitable solvents, such as chlorobenzene for polyester fibers. The extract is concentrated, transferred to methanol, taken up in an aqueous citrate buffer solution, and treated in an ultrasonic bath to disperse the colorant. Amines formed by adding sodium dithionite are transferred to a t-butyl methyl ether phase by liquid-liquid extraction using diatomaceous earth columns. The extract is concentrated, and the residue is taken up in a suitable solvent or methanol for amine detection and identification using chromatography. If amines are detected by a chromatographic method, confirmation should be made using one or more alternative methods.

The EN ISO 14362-1 and EN ISO 14362-2 standards focus on the determination of carcinogenic aromatic amines derived from azo dyes in textiles, but they differ in their scope, sample preparation methods and intended applications.

For example, while the EN ISO 14362-1 standard detects azo colorants that are directly or indirectly accessible, whether or not they are extractable, the EN ISO 14362-2 standard detects azo colorants that are not accessible under normal conditions of use (e.g. deeply embedded in the fibers).

While the EN ISO 14362-1 standard includes both surface accessible and fiber-bound azo dyes, the EN ISO 14362-2 standard applies when the colorants are strongly bound to the fibers and are inaccessible without special treatment.

EN ISO 14362-1 applies to most consumer textiles, particularly those intended for direct or prolonged skin contact. EN ISO 14362-2 is for textiles that are not expected to release dye during normal use (e.g., pigment-dyed products or embedded synthetic fibers).

In terms of testing approach, EN ISO 14362-1 simulates realistic exposure (e.g. by reductive cleavage in artificial sweating), whereas EN ISO 14362-2 requires destructive or extensive removal processes to access tightly bound dyes.

In terms of sensitivity, the EN ISO 14362-1 standard is suitable for scanning and verification on a wide range of textiles, whereas the EN ISO 14362-2 standard is more suitable for special or problematic situations.

EN ISO 14362-1 is used for T-shirts, underwear, bed linens, dyed fabrics, and similar textile products. It is used for general compliance testing under REACH. EN ISO 14362-2 is used for pigment-dyed polyester, garments with inaccessible dyes, or situations where EN ISO 14362-1 is not conclusive. It is applied when it is suspected that the dyes cannot be removed by standard methods.

The EN ISO 14362-1 standard is deemed necessary for the following reasons:

• Detects latent or bound azo dyes: Some azo dyes are so tightly chemically or physically bound to synthetic fibers (e.g., polyester, nylon) that they cannot be released using the removal methods described in ISO 14362-1. These inaccessible dyes can still degrade under certain conditions (e.g., sweat, friction, body heat) and release harmful aromatic amines when worn.
• Improves consumer safety: Ensures comprehensive textile safety by controlling all potential sources of aromatic amines, not just those that can be easily removed. This is particularly important for products subject to prolonged skin contact (e.g., lingerie, baby clothes), where even firmly bonded dyes can leach over time.
• Prevents false negatives: If tests are performed according to ISO 14362-1, some hazardous dyes may not be detected, particularly in pigment-dyed synthetic fabrics and fiber-reactive or dispersion-dyed materials. ISO 14362-2 provides a backup method to ensure that no hazardous amines are missed.
• Meets legal and regulatory compliance: Some countries and certifications (such as REACH) may require testing in accordance with ISO 14362-2 in special cases to fully meet safety obligations. Demonstrates due diligence in product safety and quality assurance.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, boasts a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with EN ISO 14362-2 Textiles - Methods for the determination of certain aromatic amines derived from azo dyes - Part 2: Determination of the use of certain azo dyes accessible by fiber extraction."