To the average person one piece of hi-vis clothing is much the same as any other. What they do not realise is the strict requirements that this type of apparel has to conform to. All most people tend to notice are the colour and generalised design, while the wearer probably does not consider it all.
The main purpose of hi-vis wear is to make the wearer “ . . .capable of visually signalling the user’s presence.” It is designed and made to make the wearer conspicuous in any light conditions to operators of any kind of vehicle during daylight hours and in darkness when headlights are in use.
Any item of hi-vis wear that carries CE markings and approval has to conform to some very strict standards. Not least of these are: –
These garments are not made to with any form of power source to make them light up or have any means of producing light. They are designed and made to reflect any available light in order to make them easy to see in virtually any light conditions.
They must, however conform to quite definitive standards as set out in EN ISO 20471:2013.
This standard is reviewed every five years and updated as required. As with all forms of technology, as new materials are developed they are tested to see whether they are appropriate for use and granted authorisation as applicable. It is thanks to this regular review process that modern hi-vis wear is more comfortable and easier to maintain than older apparel.
Materials that are used for the manufacture of hi-vis wear undergo rigorous testing that measures a variety of elements. These include; burst testing, tear resistance and reflectivity. Depending on the intended application of the material it can also be tested for rainfall performance, UV exposure and even how well it washes.
The above diagram illustrates how two Class 2 garments can be combined to make a Class 3 ensemble. Class 3 being the highest level as it provides the greatest degree of conspicuity.
While under certain circumstances a single Class 2 garment may be considered sufficiently visible, it is advised that Class 3 ensembles are (in general) worn where the risk of vehicle impact is more likely.
Although many height safety harnesses are now available in hi-vis colours, they are excluded from EN ISO 20471:2013 as they cannot provide adequate coverage of the torso with fluorescent material.