TS ISO 3864-4

TS ISO 3864-4 is the standard concerned with the colorimetric and photometric properties of the materials used for safety signs in workplaces and public areas. This part of ISO 3864 defines the colorimetric and photometric requirements and the corresponding test methods for the safety and contrast colours identified in ISO 3864-1. In practical terms, it addresses not just the symbol or sign layout, but the measurable optical behaviour of the sign material itself.

Why colour performance matters in safety signs

In safety signage, colour carries meaning as well as visibility. Colourimetric concepts describe the measurable appearance of colour, while photometric concepts deal with how a material behaves under light, including aspects that affect perceived brightness and visibility. Named safety colours such as red, yellow or green, together with contrast colours, are therefore not only design choices but also controlled technical properties. This standard provides a common basis for assessing those properties.

What this part covers

• Applies to safety signs used in workplaces and public areas.
• Focuses on the specified safety and contrast colours named in ISO 3864-1.
• Sets out colorimetric and photometric requirements for those colours.
• Includes test methods for evaluating those properties.

In general technical terms, reliable colour control helps keep signs visually consistent across production batches and helps preserve intended recognition under different lighting conditions. In printed, coated or film-based sign materials, pigments, surface finish and light reflection can all influence the result. The value of this standard is that it gives manufacturers, test labs and specifiers a shared measurement framework for safety-sign colour performance.