Overview
EN ISO 12624:2022 - Thermal insulating products for building equipment and industrial installations - Determination of trace quantities of water‑soluble chloride, fluoride, silicate, sodium ions and pH (ISO 12624:2022) - specifies equipment and procedures to quantify trace amounts of water‑soluble chloride (Cl−), fluoride (F−), silicate (SiO3 2− or related), sodium (Na+) and the pH of an aqueous extract of thermal insulating products. The standard applies to insulation used in building services and industrial installations and is particularly relevant where insulating materials contact stainless austenitic steel, since these ions can affect the risk of stress corrosion cracking. It supersedes EN 13468:2001 and updates prior editions of ISO 12624.
Key topics
- Scope and purpose: procedures for preparing aqueous extracts from insulating test specimens and for measuring trace soluble ions and pH.
- Apparatus and materials: specification of glassware and analytical equipment appropriate for trace analysis and low‑background leaching (including guidance for borosilicate equipment in Annex C).
- Sample preparation: conditioning, specimen dimensions, number of specimens and leaching/ extraction conditions to obtain representative aqueous extracts.
- Analytical methods: options for determination of ions and pH, including:
- Ion chromatography and silver nitrate titration for chloride;
- spectrophotometric methods for fluoride (e.g., zirconium‑SPADNS, Annex A);
- spectrometric or colorimetric silicate determination and sodium measurement (see Clause 7 and Clause 8 in the standard);
- pH measurement using a calibrated pH meter.
- Calculation, expression and reporting: how to express results, accuracy considerations and required test‑report contents.
- Informative guidance: Annex B provides context on use and interpretation relevant to corrosion risk.
Applications and users
Who benefits from EN ISO 12624:2022:
- Manufacturers of thermal insulating products - to characterize product chemistry and demonstrate suitability for specific installations.
- Independent testing laboratories - to perform standardized leachate testing and provide comparable data.
- Specifiers and installers of building services and industrial insulation - to assess material compatibility with metallic substrates (especially stainless austenitic steel).
- Corrosion engineers and asset owners - to evaluate risk of chloride/fluoride‑induced stress corrosion cracking and to support material selection.
- Regulators and conformity bodies - for harmonized test methods and reporting.
Keywords: EN ISO 12624:2022, thermal insulating products, trace ions, chloride, fluoride, silicate, sodium, pH, stress corrosion cracking, aqueous extract, ion chromatography, zirconium SPADNS.
Related standards
- ISO 10136‑1 and ISO 10136‑2 (analysis of extract solutions - silicon dioxide and sodium/potassium by spectrometric methods)
- References and coordination through ISO/TC 163 and CEN/TC 88 (thermal insulation standards).