Overview
EN ISO 10545-15:2021 specifies a standardized laboratory method for the determination of lead (Pb) and cadmium (Cd) given off by ceramic tiles, focusing on surface release from glazed and other tile finishes. Prepared by ISO/TC 189 in collaboration with CEN/TC 67, this edition updates and replaces earlier versions and is intended to support manufacturers, testing laboratories and regulators in assessing tile safety and compliance.
Key test features:
- Exposure of the tile surface to a 4 % (v/v) acetic acid test solution.
- Controlled conditions: temperature of (20 ± 2) °C and a 24 h ± 30 min exposure period.
- Analysis of the extract for Pb and Cd, for example by atomic absorption spectrometry.
- Results expressed as mass of metal released per unit surface area (mg per dm²).
Key Topics
- Principle: The surface of a tile is covered and a defined volume of acetic acid solution contacts the glazed surface; metals released into solution are quantified.
- Reagents: Use grade-2 water and reagents complying with ISO 6353-2 where referenced; the test solution is 4 % acetic acid (40 mL glacial acetic acid in 960 mL water).
- Apparatus: Atomic absorption spectrometer or other suitable instrumentation for quantifying Pb and Cd in solution.
- Specimen preparation: Surfaces must be clean and grease-free; a neutral-cure silicone ribbon (~6 mm) is applied to form a containment well and an impervious cover placed to limit evaporation and contamination.
- Procedure: Measure the contact area and add the test solution volume; after 24 h mix and take an aliquot for analysis. Account for reagent blanks when calculating metal content.
- Expression of results: Results are calculated from the measured metal concentration (mg/L), the test solution volume (mL) and the tested surface area (dm²) to give mg of metal per dm².
Applications
- Quality control in tile production to monitor glaze formulations and firing processes that influence metal release.
- Regulatory compliance testing where tiles must meet limits on heavy metal release for consumer safety and environmental protection.
- Product certification and specification: Useful for manufacturers providing demonstrable test evidence for glazed ceramic tile safety.
Related Standards
- ISO 3696: Water for analytical laboratory use - Specification and test methods.
- ISO 6353-2: Reagents for chemical analysis - Specifications (first series).
- The ISO 10545 series: other parts cover physical and mechanical tests for ceramic tiles.
This standard provides a reproducible, internationally accepted method to quantify Pb and Cd release from tile surfaces, enabling consistent laboratory practice and clearer communication between manufacturers, testing labs and regulators.
