ISO 4665:2016

Overview

ISO 4665:2016 - Rubber, vulcanized or thermoplastic - Resistance to weathering - specifies standardized methods to expose vulcanized and thermoplastic rubbers to natural or artificial weathering and to determine resulting changes in colour, appearance, and physical properties. The standard aligns rubber weathering tests with existing plastics weathering procedures and provides a uniform approach for conditioning, exposure, assessment, and reporting.

Key topics and requirements

• Scope: Methods for exposure (natural sunlight, glass‑filtered daylight, intensified daylight using Fresnel mirrors, and laboratory light sources) and measurement of resulting changes.
• Exposure procedures: Follow relevant ISO methods for natural and artificial exposure (see ISO 877 series and ISO 4892 series). Strain tests use ISO 1431-1 procedures.
• Controls and reference materials: Use file test pieces, masked areas and recommended weathering reference materials (Annex A) to allow meaningful comparison and reproducibility.
• Colour assessment:
  • Instrumental: Use colorimetric equipment conforming to ISO 18314-1.
  • Visual: Use the grey scale for change in colour (ISO 105‑A02).
• Appearance and physical properties:
  • Visually inspect for other appearance changes (cracking, crazing, etc.) and assess ozone cracking per ISO 1431-1.
  • Measure mechanical/physical properties using apparatus and procedures from the relevant material standards; condition samples per ISO 23529.
• Test pieces: Requirements for sample form, location of cuts from exposed sheets, and avoidance of removing exposed faces during preparation.
• Results & reporting: Express changes in colour, appearance and physical properties in agreed formats (see sections on expression of results and test report).

Practical applications and users

ISO 4665:2016 is intended for:

• Rubber and elastomer manufacturers performing product development and quality control.
• Independent testing laboratories validating durability and suitability for outdoor service.
• R&D teams and material engineers comparing formulations and additives for UV/ weather resistance.
• OEMs and specifiers evaluating components such as seals, hoses, gaskets and outdoor rubber parts for lifetime performance.

Benefits include reproducible weathering data, consistent colour/appearance assessment, and standardized procedures to support specification, compliance, and product improvement.

Related standards

• ISO 877 series (exposure to solar radiation - plastics)
• ISO 4892 series (laboratory light sources; xenon-arc, fluorescent UV, carbon-arc)
• ISO 18314-1 (analytical colourimetry)
• ISO 105-A02 (grey scale for colour change)
• ISO 1431-1 (ozone resistance)
• ISO 23529 (sample preparation and conditioning)

Keywords: ISO 4665, rubber weathering resistance, vulcanized rubber, thermoplastic rubber, weathering testing, colour change, artificial weathering, natural weathering.