Overview
ISO 16181-1:2021 - "Footwear - Critical substances potentially present in footwear and footwear components - Part 1: Determination of phthalate with solvent extraction" - specifies a laboratory test method for the qualitative and quantitative determination of phthalates in footwear and footwear components. The method uses solvent extraction (typically toluene) with ultrasonic treatment followed by analysis with gas chromatography–mass spectrometry (GC‑MS). Annex A lists the target phthalates; the method can be validated for additional phthalates if required.
Key topics and technical requirements
- Scope: Detect and quantify phthalate compounds in footwear materials (coated leather, textiles, polymers, etc.).
- Extraction principle: Ultrasonic extraction in toluene at about 60 °C for 1 hour; THF is an alternative solvent and extraction procedure for PVC materials.
- Sample preparation: Materials are removed from footwear, cut into small pieces (≈3–5 mm), and weighed (typical specimen masses include ~1 g; PVC uses ~0.5 g).
- Analytical technique: GC‑MS with appropriate calibration curves and internal standards (e.g., deuterated phthalates or diphenylphthalate).
- Calibration & quantification: Preparation of stock and calibration solutions, use of internal standard, calculation of individual phthalate content and summed phthalates where required.
- Quality controls: Method blanks, performance evaluation (interlaboratory results are provided in annexes), and instrument detection limits guidance.
- Safety & handling: The procedure involves hazardous solvents and requires laboratory safety measures and environmental considerations.
Practical applications
- Compliance testing: Laboratory confirmation of phthalate content to support compliance with national and regional chemical restrictions in consumer products.
- Product quality control: Routine screening by manufacturers to monitor phthalate levels in raw materials, components and finished footwear.
- Supplier verification: Incoming material testing for downstream manufacturing and procurement decisions.
- Forensic and regulatory investigations: Independent testing by conformity assessment bodies, regulators, and accredited test laboratories.
Who uses this standard
- Footwear manufacturers and component suppliers
- Accredited testing laboratories and QA/QC teams
- Regulatory authorities and compliance officers
- Product safety consultants and third‑party auditors
Related standards
- ISO 16181-2 (other analytical method for phthalates - complementary method)
- ISO/TR 16178:2012 and CEN/TR 16417 (materials likely to contain phthalates)
- ISO 4787:2010 (laboratory volumetric glassware reference)
ISO 16181-1:2021 is a practical, GC‑MS‑based standard for accurate phthalate determination in footwear, enabling manufacturers and labs to implement consistent solvent‑extraction testing and report reliable quantitative results.