Overview
ISO 20471:2013 - "High visibility clothing - Test methods and requirements" sets international requirements for clothing intended to visually signal a wearer’s presence in high‑risk situations. The standard defines performance criteria for colour, retroreflection, minimum material areas and placement to ensure conspicuity in daylight and under vehicle headlight illumination at night. It applies to high-risk (not medium/low-risk) situations and includes test methods, marking and manufacturer information requirements.
Key topics and technical requirements
- Classification: garments are grouped into three classes (1, 2, 3) linked to risk and minimum visible areas. The class determines minimum areas of background (fluorescent) and retroreflective materials (see Table 1 in the standard).
- Example minimums (from Table 1): Background material: Class 3 = 0.80 m², Class 2 = 0.50 m², Class 1 = 0.14 m². Retroreflective: Class 3 = 0.20 m², Class 2 = 0.13 m², Class 1 = 0.10 m².
- Design and placement: garments must provide 360° visibility - horizontal retroreflective bands and fluorescent materials should encircle the torso, trousers and sleeves. Class 3 garments must cover the torso and include sleeves or full-length trouser legs with retroreflective bands.
- Photometric and colour performance: requirements and measurement methods for retroreflective photometric performance, fluorescent colour values and colour fastness (including ageing and Xenon exposure).
- Material and durability tests: tensile, tear, abrasion, dimensional change, thermal and water‑vapour resistance (e.g., ISO 11092), and specific tests for retroreflection after physical and wash exposure.
- Test methods and annexes: sampling/conditioning, measurement procedures (CIE references), wet retroreflection (Annex C), industrial wash positioning (Annex B) and design guidelines (Annex D).
- Marking and manufacturer information: required labeling and user information, including garment class and instructions for use and care.
Practical applications and users
ISO 20471 is used by:
- Manufacturers and designers of high‑visibility garments to certify products meet international performance criteria.
- Testing laboratories and conformity assessment bodies to perform standardized tests.
- Procurement teams, safety managers and regulators specifying PPE for road workers, emergency responders, construction, airports, railways and other high‑risk environments.
- Employers and safety officers conducting risk assessments to select the appropriate garment class for specific work conditions.
Practical notes: selection should be based on risk assessment; laboratory test results can differ from real‑world performance (dirt, wear, cleaning and storage affect conspicuity).
Related standards
ISO 20471 references multiple textile and photometric standards (ISO 105 series for colour fastness, ISO 11092 for thermal/water‑vapour resistance, CIE colorimetry and retroreflection measurement standards). These referenced standards support the required test methods and measurements.
