This International Standard specifies requirements for high-visibility clothing which is capable of signalling the user's presence visually, intended to provide conspicuity of the user in high-risk situations under any light conditions by day and under illumination by vehicle headlights in the dark. For further information concerning risk situations see Annex A. This standard does not apply to medium-risk and low-risk situations Performance requirements are included for colour and retroreflection as well as for the minimum areas and for the placement of the materials in protective clothing.