TS ISO 3864-4

TS ISO 3864-4 addresses the colorimetric and photometric properties of the materials used for safety signs in workplaces and public areas. The technical focus is not only the visual design of the sign itself, but also how the sign material supports consistent colour appearance and visible contrast in real use.

The standard gives colorimetric and photometric requirements and test methods for the named safety and contrast colours defined in ISO 3864-1. In general technical terms, colorimetry is concerned with measuring and specifying colour numerically, while photometry deals with light-related properties such as brightness, luminous response and reflectance. That distinction matters because the same colour designation can look different depending on the substrate, coating, print process or viewing conditions.

What this part adds to safety sign design

Safety signs are used to convey warnings, prohibitions, mandatory actions and emergency information. For that reason, colour recognisability and contrast are not cosmetic details: they are part of the sign’s ability to communicate quickly and clearly. This part of ISO 3864 provides a technical framework for measuring those material properties, helping manufacturers and specifiers assess whether a sign material matches the intended visual performance.

• It applies to safety sign materials used in workplaces and public areas.
• It covers the named safety and contrast colours referenced in ISO 3864-1.
• It combines colour specification with visibility-related photometric characteristics.
• It includes requirements and test methods for evaluating those properties.