Overview
ISO 9185:2025 - "Protective clothing - Assessment of resistance of materials to molten metal splash" specifies a laboratory method to assess the heat penetration resistance of materials used in protective clothing against large splashes of molten metal. The standard gives specific procedures for molten aluminium, cryolite, copper, iron and mild steel, while the test principle can be applied to other molten materials with appropriate operator safeguards. A key caution: good resistance to a pure molten metal does not automatically predict performance against industrial slag.
Key topics and technical requirements
- Test principle: pouring measured masses of molten metal onto a specimen supported at an angle and assessing thermal penetration using an embossed PVC sensor film placed directly behind the specimen.
- Molten metal splash index: the minimum mass of molten metal that causes measurable damage to the PVC sensor film.
- Apparatus & materials:
- Crucible (typical brim-full capacity ~190 ml) and detachable holder for safe transfer.
- Furnace capable of at least 100 °C above specified pouring temperatures (molten metal temps up to ~1 650 °C).
- Temperature probe (thermocouple or non-contact) with a permissible error of ±10 °C.
- Motor-driven pouring apparatus to control pour angle and rotation.
- PVC sensor film: embossed thermoplastic film (approx. 300 ± 30 g/m²). Annex B details calibration and thermal characteristics; a new piece of film is used for each pour and should be calibrated no more than 6 months before testing.
- Procedures: includes iterative and performance level–based testing, void tests, and reporting requirements. Operator safety measures and protective arrangements are specified (see Clause 8).
- Updates in 2025 edition: revised PVC sensor film criteria, optional metal support beneath specimens (for non‑aluminium/cryolite tests), and a performance level‑based testing procedure (Clause 10.2, Annex C).
Applications and users
ISO 9185:2025 is used by:
- Manufacturers of protective clothing and PPE designers validating material choices against molten metal splash hazards.
- Independent test laboratories performing standardized molten metal resistance tests.
- Occupational safety engineers, plant safety managers and procurement teams specifying PPE for foundries, aluminium smelters, steel mills and metal‑casting operations.
- Regulators and conformity assessment bodies evaluating compliance and performance claims.
Practical use cases include material selection, comparative performance testing, QA of protective garments, and specifying minimum molten metal splash indexes for PPE procurement.
Related standards
- ISO 11610:2023 (reference for molten metal splash index definition)
- ISO/IEC 17025 (general laboratory competence and test accreditation)
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