Overview
EN ISO 877-1:2025 - Plastics - Methods of exposure to solar radiation - Part 1: General guidance (ISO 877-1:2025) is the CEN-adopted European version of the ISO guidance for outdoor exposure testing of plastics. It provides general guidance on selection and use of solar radiation exposure methods (detailed in subsequent parts of the ISO 877 series) and specifies how to determine solar radiant exposure. The standard applies to all kinds of plastic materials, products and product portions. It does not cover black-box accelerated weathering; for those tests see ASTM G7 and ASTM D4141.
Keywords: EN ISO 877-1:2025, solar radiation exposure, plastics, radiant exposure, outdoor exposure testing, weathering.
Key topics and technical requirements
The standard focuses on practical requirements and good practice for solar-exposure testing, including:
- Principle and scope: Guidance on direct (natural) and indirect exposure methods and how to interpret results.
- Apparatus: General requirements for exposure racks and instruments for measuring climatic factors, with specific emphasis on measurement of solar radiant exposure and other climate-measuring instruments.
- Test specimens: Recommendations for specimen form, preparation, number, conditioning and storage before exposure.
- Exposure conditions: Classification of climates and selection of exposure types (orientation, tilt, location) appropriate to intended service environments.
- Exposure stages and duration: Guidance on defining exposure stages, exposure duration and the importance of reporting cumulative solar radiant exposure.
- Procedure: Mounting of specimens and reference materials, climatic observations, and determination of changes in properties.
- Results and reporting: How to express changes in properties, document exposure stages and climatic conditions, and the required content of the test report.
The document also includes an informative Annex A with climate classification guidance.
Practical applications and users
EN ISO 877-1:2025 is intended for:
- Plastics manufacturers assessing UV and solar durability of materials and additives.
- Test laboratories designing outdoor exposure programs and reporting results.
- Product designers and engineers specifying materials for outdoor applications (building components, automotive parts, exterior consumer goods).
- R&D and quality assurance teams comparing materials, formulating stabilizers, or validating lifetime performance.
- Regulators and procurement bodies requiring standardized exposure data.
Use this standard to select appropriate outdoor-exposure methods, measure and report solar radiant exposure, and interpret variability across climates.
Related standards
Adopting EN ISO 877-1:2025 helps ensure consistent, comparable outdoor exposure testing and reliable evaluation of plastics’ resistance to solar radiation.