Overview - ISO 4582:2025 (Plastics, Colour and Property Changes after Weathering)
ISO 4582:2025 specifies standardized methods for determining changes in colour, appearance and variations in mechanical or other properties of plastics after exposure to glass‑filtered solar radiation, natural weathering or simulated solar radiation from laboratory sources. The fifth edition (2025) updates procedures for measurement, data analysis and reporting so results from different exposure regimes (outdoor or accelerated) can be compared when appropriate.
Keywords: ISO 4582, plastics weathering, colour change, accelerated ageing, solar radiation, natural weathering, mechanical properties.
Key topics and technical requirements
- Scope and purpose: Methods to quantify changes in colour and other appearance attributes and to detect variations in mechanical/functional properties after exposure.
- Exposure context: Exposures are performed under the conditions defined in specific exposure standards (for example ISO 877 series and ISO 4892 series).
- Colour measurement:
- Instrumental methods (e.g., colourimetric measurements) and visual assessment procedures are described for assessing change in colour and appearance.
- Test specimen preparation, apparatus and procedures for repeatable colour evaluation are specified.
- Mechanical and other properties:
- Procedures differ depending on whether the test method is destructive or non‑destructive.
- Requirements for initial property determination, storage of file specimens, and post‑exposure testing are included.
- Data handling and statistics:
- Guidance on expression of results, precision and statistical analysis (referencing ISO 2602) is provided, including methods to determine times to specified loss of property.
- Quality, reporting and precision:
- Required elements for the test report and precision expectations are set out to support reproducible lab-to-lab comparisons.
- Supplementary guidance:
- Annexes cover statistical formulae, effects of surface cleaning on assessment, and measurements of changes in mechanical properties.
Practical applications and users
Who uses ISO 4582:
- Materials scientists and polymer formulators assessing UV‑stability or colourfastness.
- Third‑party test laboratories performing accelerated ageing and outdoor weathering tests.
- Quality engineers and product developers validating durability and appearance retention.
- Specifiers, procurement and regulatory bodies writing performance requirements for plastic products used outdoors (automotive trims, building materials, consumer goods, coatings).
Practical benefits:
- Enables objective, repeatable comparison of colour and property changes across formulations, coatings and products.
- Supports accelerated testing strategies by aligning measurement and reporting with natural weathering reference data.
Related standards
- ISO 877 series (weathering exposures)
- ISO 4892 series (artificial weathering devices)
- ISO/CIE 11664 (colorimetry)
- ISO 10640 (chemical change measurements)
- ISO 2602 (statistical interpretation)
- ISO 291 (conditioning atmospheres)
Use ISO 4582 when you need standardized, reproducible assessment of how solar radiation and weathering affect the appearance and functional properties of plastic materials.