ISO 18526-2:2020

Overview - ISO 18526-2:2020 (Eye and face protection - Physical optical properties)

ISO 18526-2:2020 defines the reference test methods for determining the physical optical properties of personal eye and face protection (safety spectacles, face shields, goggles, filters). It specifies measurement principles, apparatus, calibration, calculation methods, uncertainty limits and test report requirements for optical performance. The standard is intended as a reference; products governed by other requirements standards follow those test methods unless alternate methods are shown to be equivalent with no greater measurement uncertainty.

Key topics and technical requirements

The standard covers a comprehensive set of optical tests and requirements, including:

• Transmittance measurements - general methods, position/direction of measurement, wavelength intervals, and reporting rules.
• Luminous transmittance - spectral calculation, broadband measurement methods, uniformity across the field and left/right matching at reference points.
• Ultraviolet (UV) transmittance - spectral and solar UV metrics (UV-A, UV-B, mean values) and reporting.
• Blue‑light transmittance - metrics for solar and artificial sources and both spectral and broadband methods.
• Infrared (IR) transmittance - near-IR, IR‑A/IR‑B and solar IR reporting.
• Relative visual attenuation for traffic-signal detection - calculation and reporting guidance for Qsignal.
• Spectral reflectance and luminous reflectance - specular/total, geometries (0°/45°, 45°/0°) and uncertainty considerations.
• Scattered light - wide-angle and narrow-angle scatter test principles, apparatus, procedures and calculations.
• Polarization - plane of transmission and polarizing efficiency test procedures (spectrophotometric and broadband methods).
• Photochromic lenses - light sources and radiation conditions to approximate solar spectral distributions for testing.
• Measurement uncertainty and reporting - requirements for uncertainty of measurement and clear test report content.

Practical applications - who uses ISO 18526-2

• Manufacturers and R&D teams - validate optical performance during design and quality control.
• Independent test laboratories and certification bodies - perform reference measurements for compliance and certification.
• Procurement and safety managers - specify objective optical criteria in purchasing and PPE selection.
• Regulators and standards developers - harmonize test methods and compare alternative measurement procedures.
• Product designers - assess effects of coatings, tints, polarization and photochromic behavior on visual performance.

Related standards and implementation notes

• ISO 18526-2 is a test-method part of the broader eye and face protection standardization landscape and is used alongside product requirements standards (national/regional standards or ISO requirement parts). Alternative test methods can be accepted only if equivalence and measurement uncertainty are demonstrated.

Keywords: ISO 18526-2:2020, eye and face protection, optical properties, luminous transmittance, UV transmittance, blue-light, IR transmittance, scattered light, polarization, photochromic lenses, test methods.