This International Standard specifies requirements for protective clothing visually signalling the user's presence with the intent of providing conspicuity of the wearer in dangerous situations in any daylight condition and under illumination of headlights in the dark. Conspicuity is the property describing an object's capability of attracting visual attention. This is a particularly important feature in complex environments which have visually competing objects. Conspicuity is contingent on luminance contrast, colour contrast, pattern and design, and an object's motion characteristics relative to the ambient background against which this object is seen. Performance requirements are included in this International Standard for colour and retroreflection as well as for the minimum areas and for the placement of the materials in protective clothing. This standard is not applicable for high visibility clothing for sports and recreation. Other standards exist for this field (see EN 1150:1999 and EN 13356:2001). This standard is not applicable for classical worker clothing for which the manufacturer has designated that this is not protective clothing and that it does not comply with the essential requirements, even if small amounts of conspicuity-enhancing materials have been used for another purpose. Potential users of this standard are testing institutions, certifications institutions and manufacturers. This standard has been prepared by Technical Committee ISO/TC 94 "Personal safety - Protective clothing and equipment" in collaboration with Technical Committee CEN/TC 162 "Protective clothing including hand and arm protection and lifejackets" (secretariat: DIN, Germany). The responsible German standardization committee is Working Committee NA 075-05-07 AA "Spezielle Schutzkleidung (Warnkleidung und Zubehör)" ("Special protective clothing (Visibility clothing and accessories)") at the Personal Protective Equipment Standards Committee (NPS).