Polycyclic aromatic hydrocarbons (PAHs) in footwear according to ISO 16190:2021

The process begins with the careful selection of representative test pieces, chosen from various parts of the footwear—such as the sole, insole, or upper. These components are then meticulously cut or ground into smaller fragments. This step is essential to ensure that the subsequent extraction of substances is both thorough and efficient.

Once prepared, the fragmented samples undergo a solvent-based extraction process. Commonly used solvents like toluene or n-hexane are employed to draw out polycyclic aromatic hydrocarbons (PAHs) from the material. This extraction typically takes place in a controlled laboratory setting, utilizing methods such as Soxhlet extraction, ultrasonic baths, or mechanical shaking to maximize yield and consistency.

Following extraction, the resulting solution is filtered and concentrated to isolate the analytes of interest. The refined extract is then subjected to analytical testing, most often using gas chromatography coupled with either mass spectrometry (GC-MS) or flame ionization detection (GC-FID). The choice of technique depends on the sensitivity required and the equipment available. The analysis focuses on detecting eight priority PAHs, as outlined in the EU REACH Annex XVII, though additional compounds may be included depending on regulatory requirements.

To ensure accuracy, calibration standards are used during the quantification phase. Each PAH is measured individually, with its concentration determined based on its unique response factor, allowing for precise and reliable results.