Overview
EN ISO 2810:2020 - Paints and varnishes: Natural weathering of coatings - Exposure and assessment specifies how to plan, carry out and report natural weathering tests to determine the resistance of coatings or coating systems to solar radiation and atmospheric exposure. The standard covers both direct weathering and weathering behind window glass, and replaces EN ISO 2810:2004. It does not address special atmospheric influences such as industrial pollution.
Key topics and technical requirements
- Scope and purpose: Defines parameters to select appropriate natural weathering procedures for assessing coating durability and resistance to sun and atmosphere.
- Exposure conditions: Choice of exposure site (marine, rural, etc.), rack height, angle and orientation (racks normally face the equator), terrain effects and specimen mounting to minimise mechanical stresses and cross-contamination.
- Specimen requirements: Guidance on substrates, replication for anisotropic materials (e.g., wood, steel) and optional masked areas for comparative evaluation.
- Exposure duration and criteria: Tests are normally time-based; the exposure period should be at least one year (or multiples) and reproducibility improves if exposures start at the same time of year (preferably spring). Optionally, define test end by level of degradation or by radiant exposure (solar dosage).
- Climate and monitoring: Continuous monitoring and full reporting of climatic conditions are required. Annexes address environment/climate and climate classification (updated to ISO 877-1:2009).
- Instrumentation: Clause 6 specifies instruments for measuring solar radiation and climate factors - pyranometers, pyrheliometers, total-UV and narrow-band UV radiometers - plus other climate-measuring devices.
- Evaluation and reporting: Procedures for assessing properties, precision, and the mandatory content of the test report are included.
- Notes and updates: The 2020 edition revised climatic observations (the previous “time of wetness” entry was replaced by a note referencing ASTM Practice G84) and updated normative references.
Practical applications
- Comparative outdoor durability testing of paints, varnishes and coating systems.
- Validation of product performance claims, selection of coatings for specific climates and end-uses (e.g., marine, architectural glazing).
- Support for warranty, specification compliance, and failure analysis through standardized exposure and documented climatic data.
- Benchmarking and correlation with accelerated weathering or laboratory tests by relating results to measured radiant exposure.
Who should use this standard
- Coating manufacturers and formulators
- Independent test laboratories and certification bodies
- Architects, specifiers and product compliance teams
- R&D and quality assurance professionals working on outdoor durability
Related standards
Keywords: EN ISO 2810:2020, natural weathering, coatings, paint durability testing, exposure racks, radiant exposure, UV radiometers, outdoor exposure testing.